file which includes the original illustrations and sound recordings of clock chimes4 ,see #fadid-;h4htm or #fadid-;h4zip3 7https3_/_/www4gutenberg4org_/cache_/epu b_/#fadid_/pg#fadid-;images4html7 or 7https3_/_/www4gutenberg4org_/files_/#fa did_/fadid-;h4zip7 ,images of the original pages are available through ,internet ,archive4 ,see https3_/_/archive4org_/details_/moderncl ockstudy#jj;good ,some characters might not display properly in this ,,utf-#h text file 7e4g41 empty squares74 ,if so1 the reader should consult the html version or the original page images noted above4 ,transcriber's note3 ,text enclosed by underscores is in italics 7italics74 ,text enclosed by equal signs is in bold face 7bold74 ,small capitals have been converted to ,,solid capitals4 ,the ,modern ,clock ,a ,study of ,time ,keeping ,mechanism2 ,its ,construction1 ,regulation and ,repair4 by ,,ward ,l4 ,,goodrich ,author of the ,watchmaker's ,lathe1 ,its ,use and ,abuse4 ,with ,numerous ,illustrations and ,diagrams ,,chicago ,hazlitt ,walker1 ,publishers #aije ,copyrighted #aije by ,hazlitt ,walker4 ,,table ,,of ,,contents ,,chap4 ,,page ,i4 ,,the ,,necessity ,,for ,,better ,,skill ,,among ,,clockmakers4 #c ,,ii4 ,,the ,,natural ,,laws ,,governing ,,pendulums4 #aj ,,iii4 ,,compensating ,,pendulums4 #bc ,,iv4 ,,the ,,construction ,,of ,,mercurial ,,pendulums4 #ec ,v4 ,,regulations1 ,,suspensions1 ,,crutches ,,and ,,minor ,,points4 #gi ,,vi4 ,,torsion ,,pendulums ,,for ,,four-,,hundred ,,day ,,clocks4 #ia ,,vii4 ,,peculiarities ,,of ,,angular ,,measurement-- ,,how ,,to ,,read ,,drawings4 #ih ,,viii4 ,,the ,,graham ,,or ,,dead ,,beat ,,escapement4 #aji ,,ix4 ,,le ,,paute',s ,,pin ,,wheel ,,escapement4 #ace ,x4 ,,the ,,recoil ,,or ,,anchor ,,escapement4 #ada ,,xi4 ,,the ,,dennison ,,or ,,gravity ,,escapement4 #aej ,,xii4 ,,the ,,cylinder ,,escapement ,,as ,,applied ,,to ,,clocks4 #afc ,,xiii4 ,,the ,,detached ,,lever ,,escapement ,,as ,,applied ,,to ,,clocks4 #ahd ,,xiv4 ,,plates1 ,,pivots ,,and ,,time ,,trains4 #aih ,,xv4 ,,springs1 ,,weights ,,and ,,power4 #bfd ,,xvi4 ,,motion ,,work ,,and ,,striking ,,trains4 #bic ,,xvii4 ,,cleaning ,,and ,,repairing ,,cuckoo ,,clocks4 #cai ,,xviii4 ,,snail ,,striking ,,work1 ,,english1 ,,french ,,and ,,american4 #ccj ,,xix4 ,,the ,,construction ,,of ,,simple ,,and ,,perpetual ,,calendars4 #cdg ,,xx4 ,,hammers1 ,,gongs ,,and ,,bells4 #cfg ,,xxi4 ,,electric ,,clocks ,,and ,,batteries4 #cgf ,,xxii4 ,,the ,,construction ,,and ,,repair ,,of ,,dials4 #dbf ,,xxiii4 ,,clock ,,casing ,,and ,,case ,,repairs4 #ddf ,,xxiv4 ,,some ,,hints ,,on ,,making ,a ,,regulator4 #dfc ,,list ,,of ,,illustrations #die ,,index #dig ,,chapter ,i4 ,,the ,,necessity ,,for ,,better ,,skill ,,among ,,clockmakers4 ,the need for information of an exact and reliable character in regard to the hard worked and much abused clock has1 we presume1 been felt by every one who entered the trade4 ,this information exists1 of course1 but it is scattered through such a wide range of publications and is found in them in such a fragmentary form that by the time a workman is sufficiently acquainted with the literature of the trade to know where to look for such information he no longer feels the necessity of acquiring it4 ,the continuous decrease in the prices of watches and the consequent rapid increase in their use has caused the neglect of the pendulum timekeepers to such an extent that good clock men are very scarce1 while botches are universal4 ,when we reflect that the average #8life' of a worker at the bench is rarely more than twenty years1 we can readily see that information by verbal instruction is rapidly being lost1 as each apprentice rushes through clock work as hastily as possible in order to do watch work and consequently each 8watchmaker0 knows less of clocks than his predecessor and is therefore less fitted to instruct apprentices in his turn4 ,the striking clock will always continue to be the timekeeper of the household and we are still dependent upon the compensating pendulum1 in conjunction with the fixed stars1 for the basis of our timekeeping system1 upon which our commercial and legal calendars and the movements of our ships and railroad trains depend1 so that an accurate knowledge of its construction and behavior forms the essential basis of the largest part of our business and social systems1 while the watches for which it is slighted are themselves regulated and adjusted at the factories by the compensated pendulum4 ,the rapid increase in the dissemination of 8standard time0 and the compulsory use of watches having a maximum variation of five seconds a week by railway employees has so increased the standard of accuracy demanded by the general public that it is no longer possible to make careless work 8go0 with them1 and1 if they accept it at all1 they are apt to make serious deductions from their estimate of the watchmaker's skill and immediately transfer their custom to some one who is more thorough4 ,the apprentice1 when he first gets an opportunity to examine a clock movement1 usually considers it a very mysterious machine4 ,later on1 if he handles many clocks of the simple order1 he becomes tolerably familiar with the time train2 but he seldom becomes confident of his ability regarding the striking part1 the alarm and the escapement1 chiefly because the employer and the older workmen get tired of telling him the same things repeatedly1 or because they were similarly treated in their youth1 and consider clocks a nuisance1 any how1 never having learned clock work thoroughly1 and therefore being unable to appreciate it4 ,in consequence of such treatment the boy makes a few spasmodic efforts to learn the portions of the business that puzzle him1 and then gives it up1 and thereafter does as little as possible to clocks1 but begs continually to be put on watch work4 ,we know of a shop where two and sometimes three workmen 7the best in the shop1 too7 are constantly employed upon clocks which country jewelers have failed to repair4 ,if clock work is dull they will go upon watch work 7and they do good work1 too71 but they enjoy the clocks and will do them in preference to watches1 claiming that there is greater variety and more interest in the work than can be found in fitting factory made material into watches1 which consist of a time train only4 ,two of these men have become famous1 and are frequently sent for to take care of complicated clocks1 with musical and mechanical figure attachments1 tower1 chimes1 etc4 ,the third is much younger1 but is rapidly perfecting himself1 and is already competent to rebuild minute repeaters and other sorts of the finer kinds of ,french clocks4 ,he now totally neglects watch work1 saying that the clocks give him more money and more fun4 ,we are confident that this would be also the case with many another ,american youth if he could find some one to patiently instruct him in the few indispensable facts which lie at the bottom of so much that is mysterious and from which he now turns in disgust4 ,the object of these articles is to explain to the apprentice the mysteries of pendulums1 escapements1 gearing of trains1 and the whole technical scheme of these measurers of time1 in such a way that hereafter he may be able to answer his own questions1 because he will be familiar with the facts on which they depend4 ,many workmen in the trade are already incompetent to teach clockwork to anybody1 owing to the slighting process above referred to2 and the frequent demands for a book on clocks have therefore induced the writer to undertake its compilation4 ,works on the subject--nominally so1 at least--are in existence1 but it will generally be found on examination that they are written by outsiders1 not by workmen1 and that they treat the subject historically1 or from the standpoint of the artistic or the curious4 ,any information regarding the mechanical movements is fragmentary1 if found in them at all1 and they are better fitted for the amusement of the general public than for the youth or man who wants to know 8how and why40 ,these facts have impelled the writer to ignore history and art in considering the subject2 to treat the clock as an existing mechanism which must be understood and made to perform its functions correctly2 and to consider cases merely as housings of mechanism1 regardless of how beautiful1 strange or commonplace those housings may be4 ,we have used the word 8compile0 advisedly4 ,the writer has no new ideas or theories to put forth1 for the reason that the mechanism we are considering has during the last six hundred years had its mathematics reduced to an exact science2 its variable factors of material and mechanical movements developed according to the laws of geometry and trigonometry2 its defects observed and pointed out2 its performances checked and recorded4 ,to gather these facts1 illustrate and explain them1 arrange them in their proper order1 and point out their relative importance in the whole sum of what we call a clock1 is therefore all that will be attempted4 ,in doing this free use has been made of the observations of ,saunier1 ,reid1 ,glasgow1 ,ferguson1 ,britten1 ,riefler and others in ,europe and of ,jerome1 ,playtner1 ,finn1 ,learned1 ,ferson1 ,howard and various other ,americans4 ,the work is therefore presented as a compilation1 which it is hoped will be of service in the trade4 ,in thus studying the modern ,american clocks1 we use the word ,american in the sense of ownership rather than origin1 the clocks which come to the ,american workmen to-day have been made in ,germany1 ,france1 ,england and ,america4 ,the ,german clocks are generally those of the ,schwartzwald 7or ,black ,forest7 district1 and differ from others in their structure1 chiefly in the following particulars3 ,the movement is supported by a horizontal seatboard in the upper portion of the case4 ,the wooden trains of many of the older type instead of being supported by plates are held in position by pillars1 and these pillars are held in position by top and bottom boards4 ,in the better class of wooden clocks the pivot holes in the pillars are bushed with brass tubing1 while the movement has a brass 'scape wheel1 steel wire pivots and lantern pinions of wood1 with steel trundles4 ,in all these clocks the front pillars are friction-tight1 and are the ones to be removed when taking down the trains4 ,both these and the modern ,swartzwald brass movements use a sprocket wheel and chain for the weights and have exposed pendulums and weights4 ,the ,french clocks are of two classes1 pendules and carriage clocks1 and both are liable to develop more hidden crankiness and apparently causeless refusals to go than ever occurred to all the ,english1 ,german and ,american clocks ever put together4 ,there are many causes for this1 and unless a man is very new at the business he can tell stories of perversity1 that would make a timid apprentice want to quit4 ,yet the ,french clocks1 when they do go1 are excellent timekeepers1 finely finished1 and so artistically designed that they make their neighbors seem very clumsy by comparison4 ,they are found in great variety1 time1 half-hour and quarter-hour strike1 musical and repeating clocks being a few of the general varieties4 ,the pendulums are very short1 to accommodate themselves to the artistic needs of the cases1 and nearly all have the snail strike instead of the count wheel4 ,the carriage clocks have watch escapements of cylinder or lever form1 and the escapement is frequently turned at right angle by means of bevel gears1 or contrate wheel and pinion1 and placed on top of the movement4 ,the ,english clocks found in ,america are generally of the 8,hall0 variety1 having heavy1 well finished movements1 with seconds pendulum and frequently with calendar and chime movements4 ,they1 like the ,german1 are generally fitted with weights instead of springs4 ,there are a few ,english carriage clocks1 fitted with springs and fuzees1 though most of them1 like the ,french1 have springs fitted in going barrels4 ,the ,american clocks1 with which the apprentice will naturally have most to do1 may be roughly divided into time1 time alarm1 time strike1 time strike alarm1 time calendar and electric winding4 ,the ,american factories generally each make about forty sizes and styles of movements1 and case them in many hundreds of different ways1 so that the workman will frequently find the same movement in a large number of clocks1 and he will soon be able to determine from the characteristics of the movement what factory made the clock1 and thus be able to at once turn to the proper catalogue if the name of the maker be erased1 as frequently happens4 ,this comparative study of the practice of different factories will prove very interesting1 as the movement comes to the student after a period of prolonged and generally severe use1 which is calculated to bring out any existing defects in construction or workmanship2 and having all makes of clocks constantly passing through his hands1 each exhibiting a characteristic defect more frequently than any other1 he is in a much better position to ascertain the merits and defects of each maker than he would be in any factory4 ,having thus briefly outlined the kinds of machinery used in measuring time1 we will now turn our attention to the examination of the theoretical and mechanical construction of the various parts4 ,the man who starts out to design and build a clock will find himself limited in three particulars3 ,it must run a specified time2 the arbor carrying the minute hand must turn once in each hour2 the pendulum must be short enough to go in the case4 ,two of these particulars are changeable according to circumstances2 the length of time run may be thirty hours1 eight1 thirty1 sixty or ninety days4 ,the pendulum may be anywhere from four inches to fourteen feet1 and the shorter it is the faster it will go4 ,the one definite point in the time train is that the minute hand must turn once in each hour4 ,we build or alter our train from this point both ways1 back through changeable intermediate wheels and pinions to the spring or weight forming the source of power1 and forward from it through another changeable series of wheels and pinions to the pendulum4 ,now as the pendulum governs the rate of the clock we will commence with that and consider it independently4 ,,chapter ,,ii4 ,,the ,,natural ,,laws ,,governing ,,pendulums4 ,,length ,,of ,,pendulum4--,a pendulum is a falling body and as such is subject to the laws which govern falling bodies4 ,this statement may not be clear at first1 as the pendulum generally moves through such a small arc that it does not appear to be falling4 ,yet if we take a pendulum and raise the ball by swinging it up until the ball is level with the point of suspension1 as in ,fig4 #a1 and then let it go1 we shall see it fall rapidly until it reaches its lowest point1 and then rise until it exhausts the momentum it acquired in falling1 when it will again fall and rise again on the other side2 this process will be repeated through constantly smaller arcs until the resistance of the air and that of the pendulum spring shall overcome the other forces which operate to keep it in motion and it finally assumes a position of rest at the lowest point 7nearest the earth7 which the pendulum rod will allow it to assume4 ,when it stops1 it will be in line between the center of the earth 7center of gravity7 and the fixed point from which it is suspended4 ,true1 the pendulum bob1 when it falls1 falls under control of the pendulum rod and has its actions modified by the rod2 but it falls just the same1 no matter how small its arc of motion may be1 and it is this influence of gravity--that force which makes any free body move toward the earth's center--which keeps the pendulum constantly returning to its lowest point and which governs very largely the time taken in moving4 ,hence1 in estimating the length of a pendulum1 we must consider gravity as being the prime mover of our pendulum4 ,illustration3 ,fig4 #a4 ,dotted lines show path of pendulum4 ,the next forces to consider are mass and weight1 which1 when put in motion1 tend to continue that motion indefinitely unless brought to rest by other forces opposing it4 ,this is known as momentum4 ,a heavy bob will swing longer than a light one1 because the momentum stored up during its fall will be greater in proportion to the resistance which it encounters from the air and the suspension spring4 ,as the length of the rod governs the distance through which our bob is allowed to fall1 and also controls the direction of its motion1 we must consider this motion4 ,referring again to ,fig4 #a1 we see that the bob moves along the circumference of a circle1 with the rod acting as the radius of that circle2 this opens up another series of facts4 ,the circumference of a circle equals #c4adaf times its diameter1 and the radius is half the diameter 7the radius in this case being the pendulum rod74 ,the areas of circles are proportional to the squares of their diameters and the circumferences are also proportional to their areas4 ,hence1 the lengths of the paths of bobs moving along these circumferences are in proportion to the squares of the lengths of the pendulum rods4 ,this is why a pendulum of half the length will oscillate four times as fast4 ,now we will apply these figures to our pendulum4 ,a body falling in vacuo1 in ,london1 moves #cb4b feet in one second4 ,this distance has by common consent among mathematicians been designated as g4 ,the circumference of a circle equals #c4adaf times its diameter4 ,this is represented as 4 ,now1 if we call the time t1 we shall have the formula3 -------------- t 7#a_/;g7 ,substituting the time1 one second1 for t1 and doing the same with the others1 we shall have3 7#cb4b ft47 #a ---------------------- #c4bfaf feet4 7#c4adaf7 ,turning this into its equivalent in inches by multiplying by #ab1 we shall have #ci4acic inches as the length of a one-second pendulum at ,london4 ,now1 as the force of gravity varies somewhat with its distance from the center of the earth1 we shall find the value of g in the above formula varying slightly1 and this will give us slightly different lengths of pendulum at different places4 ,these values have been found to be as follows3 ,inches4 ,the ,equator is #ci ,rio de ,janeiro #ci4ja ,madras #ci4jb ,new ,york #ci4ajab ,paris #ci4ac ,london #ci4ad ,edinburgh #ci4ae ,greenland #ci4bj ,north and ,south ,pole #ci4bjf ,now1 taking another look at our formula1 we shall see that we may get the length of any pendulum by multiplying 7which is #c4adaf7 by the square of the time required3 ,to find the length of a pendulum to beat three seconds3 #c #i4 #ci4acic #i #ceb4becg inches #bi4cedd feet4 ,a pendulum beating two-thirds of a second1 or #ij beats3 77 _/ #ci4acic #d ------------------------ #ag4cieb inches4 #i ,a pendulum beating half-seconds or #abj beats3 77 #ci4acic #a ---------------------- #i4ghdh inches4 #d ,,center ,,of ,,oscillation4--,having now briefly considered the basic facts governing the time of oscillation of the pendulum1 let us examine it still further4 ,the pendulum shown in ,fig4 #a has all its weight in a mass at its end1 but we cannot make a pendulum that way to run a clock1 because of physical limitations4 ,we shall have to use a rod stiff enough to transmit power from the clock movement to the pendulum bob and that rod will weigh something4 ,if we use a compensated rod1 so as to keep it the same length in varying temperature1 it may weigh a good deal in proportion to the bob4 ,how will this affect the pendulum8 ,if we suspend a rod from its upper end and place along-side of it our ideal pendulum1 as in ,fig4 #b1 we shall find that they will not vibrate in equal times if they are of equal lengths4 ,why not8 ,because when the rod is swinging 7being stiff7 a part of its weight rests upon the fixed point of suspension and that part of the rod is consequently not entirely subject to the force of gravity4 ,now1 as the time in which our pendulum will swing depends upon the distance of the effective center of its mass from the point of suspension1 and as1 owing to the difference in construction1 the center of mass of one of our pendulums is at the center of its ball1 while that of the other is somewhere along the rod1 they will naturally swing in different times4 ,illustration3 ,fig4 #b4 ,two pendulums of equal length but unequal vibration4 ,b1 center of oscillation for both pendulums4 ,illustration3 ,fig4 #c4 ,our other pendulum 7the rod7 is of the same size all the way up and the center of its effective mass would be the center of its weight 7gravity7 if it were not for the fact which we stated a moment ago that part of the weight is upheld and rendered ineffective by the fixed support of the pendulum rod1 all the while the pendulum is not in a vertical position4 ,if we support the rod in a horizontal position1 as in ,fig4 #c1 by holding up the lower end1 the point of suspension1 ,a1 will support half the weight of the rod2 if we hold it at #de degrees the point of suspension will hold less than half the weight of the rod and more of the rod will be affected by gravity2 and so on down until we reach the vertical or up and down position4 ,thus we see that the force of gravity pulling on our pendulum varies in its effects according to the position of the rod and consequently the effective center of its mass also varies with its position and we can only calculate what this mean 7or average7 position is by a long series of calculations and then taking an average of these results4 ,we shall find it simpler to measure the time of swing of the rod which we will do by shortening our ball and cord until it will swing in the same time as the rod4 ,this will be at about two-thirds of the length of the rod1 so that the effective length of our rod is about two-thirds of its real length4 ,this effective length1 which governs the time of vibration1 is called the theoretical length of the pendulum and the point at which it is located is called its center of oscillation4 ,the distance from the center of oscillation to the point of suspension is called the theoretical length of the pendulum and is always the distance which is given in all tables of lengths of pendulums4 ,this length is the one given for two reasons3 ,first1 because1 it is the timekeeping length1 which is what we are after1 and second1 because1 as we have just seen in ,fig4 #c1 the real length of the pendulum increases as more of the weight of the instrument is put into the rod4 ,this explains why the heavy gridiron compensation pendulum beating seconds so common in regulators and which measures from #ef to #fj inches over all1 beats in the same time as the wood rod and lead bob measuring #de inches over all1 while one is apparently a third longer than the other4 ,table ,showing the ,length of a ,simple ,pendulum ,that performs in one hour any given number of oscillations1 from #a to #bj1jjj1 and the variation in this length that will occasion a difference of #a minute in #bd hours4 ,calculated by ,e4 ,gourdin4 ,length ,variation in ,length ,number of in for ,one ,minute in #bd ,oscillations per ,hour4 ,millimeters4 ,hours in ,millimeters4 ---------------------------------------- ------------------ #bj1jjj #cb4b #j4jd #ai1jjj #ce4g #j4je #ah1jjj #ci4h #j4je #ag1ijj #dj4b #j4jf #ag1hjj #dj4g #j4jf #ag1gjj #da4a #j4jf #ag1fjj #da4f #j4jf #ag1ejj #db4a #j4jf #ag1djj #db4d #j4jf #ag1cjj #dc4j #j4jf #ag1bjj #dc4e #j4jf #ag1ajj #dd4j #j4jf #ag1jjj #dd4f #j4jf #af1ijj #de4a #j4jf #af1hjj #de4g #j4jf #af1gjj #df4c #j4jf #af1fjj #df4g #j4jg #af1ejj #dg4c #j4jg #af1djj #dg4i #j4jg #af1cjj #dh4e #j4jg #af1bjj #di4a #j4jg #af1ajj #di4g #j4jg #af1jjj #ej4j #j4jg #ae1ijj #ea4j #j4jg #ae1hjj #ea4f #j4jg #ae1gjj #eb4c #j4jg #ae1fjj #eb4i #j4jg #ae1ejj #ec4f #j4jg #ae1djj #ed4c #j4jh #ae1cjj #ee4j #j4jh #ae1bjj #ee4g #j4jh #ae1ajj #ef4e #j4jh #ae1jjj #eg4c #j4jh #ad1ijj #eh4j #j4jh #ad1hjj #eh4h #j4jh #ad1gjj #ei4f #j4jh #ad1fjj #fj4d #j4jh #ad1ejj #fa4c #j4jh #ad1djj #fb4a #j4ji #ad1cjj #fc4j #j4ji #ad1bjj #fc4i #j4ji #ad1ajj #fd4h #j4ji #ad1jjj #fe4g #j4ji #ac1ijj #ff4g #j4ji #ac1hjj #fg4f #j4ji #ac1gjj #fh4f #j4ji #ac1fjj #fi4f #j4ji #ac1ejj #gj4g #j4ji #ac1djj #ga4g #j4aj #ac1cjj #gb4h #j4aj #ac1bjj #gc4i #j4aj #ac1ajj #ge4a #j4aj #ac1jjj #gf4b #j4aj #ab1ijj #gg4d #j4aa #ab1hjj #gh4f #j4aa #ab1gjj #gi4i #j4aa #ab1fjj #ha4a #j4aa #ab1ejj #hb4d #j4aa #ab1djj #hc4h #j4aa #ab1cjj #he4a #j4ab #ab1bjj #hf4e #j4ab #ab1ajj #hh4j #j4ab #ab1jjj #hi4e #j4ab #aa1ijj #ia4j #j4ab #aa1hjj #ib4e #j4ac #aa1gjj #id4a #j4ac #aa1fjj #ie4g #j4ac #aa1ejj #ig4d #j4ac #aa1djj #ii4a #j4ac #aa1cjj #ajj4i #j4ad #aa1bjj #ajb4g #j4ad #aa1ajj #ajd4e #j4ad #aa1jjj #ajf4e #j4ad #aj1ijj #ajh4d #j4ae #aj1hjj #aaj4e #j4ae #aj1gjj #aab4e #j4ae #aj1fjj #aad4f #j4af #aj1ejj #aaf4h #j4af #aj1djj #aai4a #j4af #aj1cjj #aba4d #j4ag #aj1bjj #abc4h #j4ag #aj1ajj #abf4c #j4ag #aj1jjj #abh4h #j4ah #i1ijj #aca4d #j4ah #i1hjj #acd4a #j4ah #i1gjj #acf4i #j4ai #i1fjj #aci4h #j4ai #i1ejj #adb4g #j4ai #i1djj #ade4h #j4bj #i1cjj #adh4i #j4bj #i1bjj #aeb4b #j4ba #i1ajj #aee4e #j4ba #i1jjj #aei4j #j4bb #h1ijj #afb4f #j4bb #h1hjj #aff4c #j4bc #h1gjj #agj4b #j4bc #h1fjj #agc4g #j4bd #h1ejj #agh4c #j4bd #h1djj #ahb4e #j4be #h1cjj #ahg4j #j4be #h1bjj #aia4e #j4bf #h1ajj #aif4c #j4bg #h1jjj #bja4c #j4bg #g1ijj #bjf4d #j4bh #g1hjj #baa4g #j4bi #g1gjj #bag4b #j4cj #g1fjj #bbc4j #j4cj #g1ejj #bbi4j #j4ca #g1djj #bce4b #j4cb #g1cjj #bda4g #j4cc #g1bjj #bdh4e #j4cd #g1ajj #bee4g #j4ce #g1jjj #bfb4i #j4cf #f1ijj #bgj4e #j4cg #f1hjj #bgh4f #j4ch #f1gjj #bhf4i #j4ci #f1fjj #bie4g #j4dj #f1ejj #cjd4i #j4da #f1djj #cad4e #j4dc #f1cjj #cbd4e #j4dd #f1bjj #cce4a #j4df #f1ajj #cdf4b #j4dg #f1jjj #ceg4h #j4dh #e1ijj #cgj4j #j4ej #e1hjj #chb4i #j4eb #e1gjj #cif4d #j4ed #e1fjj #daj4g #j4ef #e1ejj #dbe4h #j4eh #e1djj #ddj4a #j4fj #e1cjj #deh4e #j4fb #e1bjj #dgf4c #j4fe #e1ajj #die4b #j4fg #e1jjj #eae4b #j4gj #d1ijj #ecf4e #j4gc #d1hjj #eei4a #j4gf #d1gjj #ehc4a #j4gi #d1fjj #fjh4g #j4hc #d1ejj #fcf4a #j4hf #d1djj #ffe4c #j4ij #d1cjj #fif4g #j4ie #d1bjj #gcj4b #j4ii #d1ajj #gff4c #a4jd #d1jjj #hje4j #a4ji #c1iej #hbe4e #a4ab #c1ijj #hdf4h #a4ae #c1hej #hfi4j #a4af #c1hjj #hib4j #a4ba #c1gej #iae4i #a4be #c1gjj #idj4a #a4bh #c1fej #iff4h #a4ca ---------------------------------------- ------------------ ,table of the ,length of a ,simple ,pendulum1 7,,continued47 ---------------------------------------- ---------------- ,to ,produce in #bd ,hours #a ,minute4 ---------------------------- ,number of ,length ,loss1 ,gain1 ,oscillations in ,lengthen by ,shorten by per ,hour4 ,meters4 ,millimeters4 ,millimeters4 ---------------------------------------- --------------- #c1fjj #j4iici #a4ch #a4cb #c1eej #a4jbba #a4db #a4cf #c1ejj #a4jeae #a4df #a4dj #c1dej #a4jhbb #a4ej #a4dd #c1djj #a4aadc #a4ee #a4dh #c1cej #a4adgg #a4fj #a4ec #c1cjj #a4ahbh #a4fd #a4eg #c1bej #a4baid #a4fi #a4fb #c1bjj #a4begh #a4ge #a4fg #c1aej #a4biha #a4hj #a4gc #c1ajj #a4cdjc #a4hf #a4gh #c1jej #a4chdf #a4ic #a4hd #c1jjj #a4dcab #a4ii #a4ij #b1ijj #a4ecaf #b4ac #b4jd #b1hjj #a4fdbi #b4bh #b4ah #b1gjj #a4gffi #b4df #b4ce #b1fjj #a4ijed #b4fe #b4ec #b1ejj #b4jfji #b4hg #b4gd #b1djj #b4bcfb #c4aa #b4ig #b1cjj #b4dcdi #c4ch #c4bd #b1bjj #b4ffab #c4gj #c4ed #b1ajj #b4ibjg #d4jf #c4hh #b1jjj #c4bbja #d4dh #d4bh #a1ijj #c4efh #j4jjej #j4jjdh #a1hjj #c4ige #j4jjee #j4jjec #a1gjj #d4deg #j4jjfb #j4jjei #a1fjj #e4jca #j4jjgj #j4jjfg #a1ejj #e4gbe #j4jjhj #j4jjgf #a1djj #f4egb #j4jjia #j4jjhg #a1cjj #g4fbb #j4jajf #j4jaja #a1bjj #h4ide #j4jabd #j4jaai #a1ajj #aj4fde #j4jadh #j4jadb #a1jjj #ab4hhj #j4jagi #j4jaga #ijj #ae4ijb #j4jbba #j4jbaa #hjj #bj4abf #j4jbhj #j4jbfh #gjj #bf4bhg #j4jcfe #j4jcej #fjj #ce4ggi #j4jdig #j4jdgf #ejj #ea4eba #j4jgaf #j4jfhe #djj #hj4ejb #j4aaai #j4ajga #cjj #adc4aae #j4aihi #j4aijc #bjj #cbb4jjh #j4ddgf #j4dbhb #ajj #a1bhh4jcd #a4gijd #a4gaca #fj #c1egg4hga #d4igcb #d4gehf #ej #e1aeb4ace #g4afac #f4heba #a #ab1hhj1ccg4icj #ag1ijc4fgjj #ag1acj4hejj ---------------------------------------- --------------- ,in the foregoing tables all dimensions are given in meters and millimeters4 ,if it is desirable to express them in feet and inches1 the necessary conversion can be at once effected in any given case by employing the following conversion table1 which will prove of considerable value to the watchmaker for various purposes3 ,conversion ,table of ,inches1 ,millimeters and ,french ,lines4 ,inches expressed in ,millimeters and ,french ,lines4 ------------------------------- ,equal to ----------------------- ,inches4 ,millimeters4 ,french ,lines4 ----------------------------- #a #be4ciied #aa4beiea #b #ej4giijh #bb4eaijc #c #gf4aihfb #cc4gghed #d #aja4eihaf #de4jchjf #e #abf4iigga #ef4bigeg #f #aeb4cigbe #fg4eegji #g #agg4gifgi #gh4haffj #h #bjc4aifcc #ij4jgfab #i #bbh4eiehg #aja4ccefc #aj #bec4iieda #aab4eieaf ------------------------------- ,millimeters expressed in ,inches and ,french ,lines4 -------------------------------- ,equal to -------------------- ,millimeters4 ,inches4 ,french ,lines4 ------------------------------ #a #j4jcicgjh #j4ddcbi #b #j4jghgdaf #j4hhfei #c #j4aahaabd #a4cbihi #d #j4aegdhcb #a4ggcah #e #j4aifheci #b4bafdh #f #j4bcfbbdg #b4feigh #g #j4bgeeiee #c4ajcjg #h #j4cadiffd #c4edfcg #i #j4cedccga #c4ihiff #aj #j4cicgjgi #d4dcbif -------------------------------- ,french ,lines expressed in ,inches and ,millimeters4 ------------------------------ ,equal to ----------------------- ,french ,inches4 ,millimeters4 ,lines4 ---------------------------- #a #j4jhhdad #b4beehc #b #j4aggfbh #d4eaaff #c #j4bffdda #f4gfgdi #d #j4ceebee #i4jbccb #e #j4dddjfi #aa4bgiae #f #j4ecbhhc #ac4ecdig #g #j4fbafig #ae4gijhj #h #j4gajeaj #ah4jdffc #i #j4giicbd #bj4cjbdf #aj #j4hhhach #bb4eehbi #aa #j4igfieb #bd4hadab #ab #a4jfegff #bg4jfiie ------------------------------ ,,center ,,of ,,gravity4--,the watchmaker is concerned only with the theoretical or timekeeping lengths of pendulums1 as his pendulum comes to him ready for use2 but the clock maker who has to build the pendulum to fit not only the movement1 but also the case1 needs to know more about it1 as he must so distribute the weight along its length that it may be given a length of #fj inches or of #dd inches1 or anything between them1 and still beat seconds1 in the case of a regulator4 ,he must also do the same thing in other clocks having pendulums which beat other numbers than #fj4 ,therefore he must know the center of his weights2 this is called the center of gravity4 ,this center of gravity is often confused by many with the center of oscillation as its real purpose is not understood4 ,it is simply used as a starting point in building pendulums1 because there must be a starting point1 and this point is chosen because it is always present in every pendulum and it is convenient to work both ways from the center of weight or gravity4 ,in ,fig4 #b we have two pendulums1 in one of which 7the ball and string7 the center of gravity is the center of the ball and the center of oscillation is also at the center 7practically7 of the ball4 ,such a pendulum is about as short as it can be constructed for any given number of oscillations4 ,the other 7the rod7 has its center of gravity manifestly at the center of the rod1 as the rod is of the same size throughout2 yet we found by comparison with the other that its center of oscillation was at two-thirds the length of the rod1 measured from the point of suspension1 and the real length of the pendulum was consequently one-half longer than its timekeeping length1 which is at the center of oscillation4 ,this is farther apart than the center of gravity and oscillation will ever get in actual practice1 the most extreme distance in practice being that of the gridiron pendulum previously mentioned4 ,the center of gravity of a pendulum is found at that point at which the pendulum can be balanced horizontally on a knife edge and is marked to measure from when cutting off the rod4 ,the center of oscillation of a compound pendulum must always be below its center of gravity an amount depending upon the proportions of weight between the rod and the bob4 ,where the rod is kept as light as it should be in proportion to the bob this difference should come well within the limits of the adjusting screw4 ,in an ordinary plain seconds pendulum1 without compensation1 with a bob of eighteen or twenty pounds and a rod of six ounces1 the difference in the two points is of no practical account1 and adjustments for seconds are within the screw of any ordinary pendulum1 if the screw is the right length for safety1 and the adjusting nut is placed in the middle of the length of the screw threads when the top of the rod is cut off1 to place the suspension spring by measurement from the center of gravity as has been already described2 also a zinc and iron compensation is within range of the screw if the compensating rods are not made in undue weight to the bob4 ,the whole weight of the compensating parts of a pendulum can be safely made within one and a half pounds or lighter1 and carry a bob of twenty-five pounds or over without buckling the rods1 and the two points1 the center of gravity and the center of oscillation1 will be within the range of the screw4 ,there are still some other forces to be considered as affecting the performance of our pendulum4 ,these are the resistance to its momentum offered by the air and the resistance of the suspension spring4 ,,barometric ,,error4--,if we adjust a pendulum in a clock with an air-tight case so that the pendulum swings a certain number of degrees of arc1 as noted on the degree plate in the case at the foot of the pendulum1 and then start to pump out the air from the case while the clock is running1 we shall find the pendulum swinging over longer arcs as the air becomes less until we reach as perfect a vacuum as we can produce4 ,if we note this point and slowly admit air to the case again we shall find that the arcs of the pendulum's swing will be slowly shortened until the pressure in the case equals that of the surrounding air1 when they will be the same as when our experiment was started4 ,if we now pump air into our clock case1 the vibrations will become still shorter as the pressure of the air increases1 proving conclusively that the resistance of the air has an effect on the swinging of the pendulum4 ,we are accustomed to measure the pressure of the air as it changes in varying weather by means of the barometer and hence we call the changes in the swing of the pendulum due to varying air pressure the 8barometric error40 ,the barometric error of pendulums is only considered in the very finest of clocks for astronomical observatories1 master clocks for watch factories1 etc41 but the resistance of the air is closely considered when we come to shape our bob4 ,this is why bobs are either double-convex or cylindrical in shape1 as these two forms offer the least resistance to the air and 7which is more important7 they offer equal resistance on both sides of the center of the bob and thus tend to keep the pendulum swinging in a straight line back and forth4 ,illustration3 ,fig4 #d4 ,a1 arc of circle4 ,b1 cycloid path of pendulum1 exaggerated4 ,,the ,,circular ,,error4--,as the pendulum swings over a greater arc it will occupy more time in doing it and thus the rate of the clock will be affected1 if the barometric changes are very great4 ,this is called the circular error4 ,in ancient times1 when it was customary to make pendulums vibrate at least fifteen degrees1 this error was of importance and clock makers tried to make the bob take a cycloidal path1 as is shown in ,fig4 #d1 greatly exaggerated4 ,this was accomplished by suspending the pendulum by a cord which swung between cycloidal checks1 but it created so much friction that it was abandoned in favor of the spring as used to-day4 ,it has since been proved that the long and short arcs of the pendulum's vibration are practically isochronous 7with a spring of proper length and thickness7 up to about six degrees of arc 7three degrees each side of zero on the degree plate at the foot of the pendulum7 and hence small variations of power in spring operated clocks and also the barometric error are taken care of1 except for greatly increased variations of power1 or for too great arcs of vibration4 ,here we see the reasons for and the amount of swing we can properly give to our pendulum4 ,,temperature ,,error4--,the temperature error is the greatest which we shall have to consider4 ,it is this which makes the compound pendulum necessary for accurate time1 and we shall consequently give it a great amount of space1 as the methods of overcoming it should be fully understood4 ,,expansion ,,of ,,metals4--,the materials commonly used in making pendulums are wood 7deal1 pine and mahogany71 steel1 cast iron1 zinc1 brass and mercury4 ,wood expands 4#jjjd of its length between #cb and #bab ,f42 lead1 4#jjbh2 steel1 4#jjaa2 mercury1 4#jahj2 zinc1 4#jjbh2 cast iron1 4#jjaa2 brass1 4#jjbj4 ,now the length of a seconds pendulum1 by our tables 7#cfjj beats per hour7 is #j4iici meter2 if the rod is brass it will lengthen 4#jjb with such a range of temperature4 ,as this is practically two-thousandths of a meter1 this is a gain of two millimeters1 which would produce a variation of one minute and forty seconds every twenty-four hours2 consequently a brass rod would be a very bad one4 ,if we take two of these materials1 with as wide a difference in expansion ratios as possible1 and use the least variable for the rod and the other for the bob1 supporting it at the bottom1 we can make the expansion of the rod counterbalance the expansion of the bob and thus keep the effective length of our pendulum constant1 or nearly so4 ,this is the theory of the compensating pendulum4 ,,chapter ,,iii4 ,,compensating ,,pendulums4 ,as the pendulum is the means of regulating the time consumed in unwinding the spring or weight cord by means of the escapement1 passing one tooth of the escape wheel at each end of its swing1 it will readily be seen that lengthening or shortening the pendulum constitutes the means of regulating the clock2 this would make the whole subject a very simple affair1 were it not that the reverse proposition is also true2 viz42 ,changing the length of the pendulum will change the rate of the clock and after a proper rate has been obtained further changes are extremely undesirable4 ,this is what makes the temperature error spoken of in the preceding chapter so vexatious where close timing is desired and why as a rule1 a well compensated pendulum costs more than the rest of the clock4 ,the sole reason for the business existence of watch and clockmakers lies in the necessity of measuring time1 and the accuracy with which it may be done decides in large measure the value of any watchmaker in his community4 ,hence it is of the utmost importance that he shall provide himself with an accurate means of measuring time1 as all his work must be judged finally by it1 not only while he is working upon time-measuring devices1 but also after they have passed into the possession of the general public4 ,a good clock is one of the very necessary foundation elements1 contributing very largely to equip the skilled mechanic and verify his work4 ,without some reliable means to get accurate mean time a watchmaker is always at sea--without a compass--and has to trust to his faith and a large amount of guessing1 and this is always an embarrassment1 no matter how skilled he may be in his craft1 or adept in guessing4 ,what ,i want to call particular attention to is the unreliable and worthless character of the average regulator of the present day4 ,a good clock is not necessarily a high priced instrument and it is within the reach of most watchmakers4 ,a thoroughly good and reliable timekeeper of ,american make is to be had now in the market for less than one hundred dollars1 and the only serious charge that can be made against these clocks is that they cost the consumer too much money4 ,any of them are thirty-three and a third per cent higher than they should be4 ,about seventy-five dollars will furnish a thoroughly good clock4 ,the average clock to be met with in the watchmakers' shops is the ,swiss imitation gridiron pendulum1 pin escapement1 and these are of the low grades as a rule2 the best grades of them rarely ever get into the ,american market4 ,almost without exception1 the ,swiss regulator1 as described1 is wholly worthless as a standard1 as the pendulums are only an imitation of the real compensated pendulum4 ,they are an imitation all through1 the bob being hollow and filled with scrap iron1 and the brass and steel rods composing the compensating element1 along with the cross-pieces or binders1 are all of the cheapest and poorest description4 ,if one of these pendulums was taken away from the movement and a plain iron bob and wooden rod put to the movement1 in its place1 the possessor of any such clock would be surprised to find how much better average rate the clock would have the year through1 although there would then be no compensating mechanism1 or its semblance1 in the make-up of the pendulum4 ,in brief1 the average imitation compensation pendulum of this particular variety is far poorer than the simplest plain pendulum1 such as the old style1 grandfather clocks were equipped with4 ,a wood rod would be far superior to a steel one1 or any metal rod1 as may be seen by consulting the expansion data given in the previous chapter4 ,many other pendulums that are sold as compensating are a delusion in part1 as they do not thoroughly compensate1 because the elements composing them are not in equilibrium or in due proportion to one another and to the general mechanism4 ,to all workmen who have a ,swiss regulator1 ,i would say that the movement1 if put into good condition1 will answer very well to maintain the motion of a good pendulum1 and that it will pay to overhaul these movements and put to them good pendulums that will pretty nearly compensate4 ,at least a well constructed pendulum will give a very useful and reliable rate with such a motor1 and be a great help and satisfaction to any man repairing and rating good watches4 ,the facts are1 that one of the good grade of ,american adjusted watch movements will keep a much steadier rate when maintained in one position than the average regulator4 ,without a reliable standard to regulate by1 there is very little satisfaction in handling a good movement and then not be able to ascertain its capabilities as to rate4 ,very many watch carriers are better up in the capabilities of good watches than many of our ,american repairers are1 because a large per cent of such persons have bought a watch of high grade with a published rate1 and naturally when it is made to appear to entirely lack a constant rate when compared with the average regulator1 they draw the conclusion that the clock is at fault1 or that the cleaning and repairing are4 ,many a fair workman has lost his watch trade1 largely on account of a lack of any kind of reliable standard of time in his establishment4 ,there are very few things that a repairer can do in the way of advertising and holding his customers more than to keep a good clock1 and furnish good watch owners a means of comparison and thus to confirm their good opinions of their watches4 ,we have along our railroads throughout the country a standard time system of synchronized clocks1 which are an improvement over no standard of comparison2 but they cannot be depended upon as a reliable standard1 because they are subject to all the uncertainties that affect the telegraph lines--bad service1 lack of skill1 storms1 etc4 ,the clocks furnished by these systems are not reliable in themselves and they are therefore corrected once in twenty-four hours by telegraph1 being automatically set to mean time by the mechanism for that purpose1 which is operated by a standard or master clock at some designated point in the system4 ,now all this is good in a general way2 but as a means to regulate a fine watch and use as a standard from day to day1 it is not adequate4 ,a standard clock1 to be thoroughly serviceable1 must always1 all through the twenty-four hours1 have its seconds hand at the correct point at each minute and hour1 or it is unreliable as a standard4 ,the reason is that owing to train defects watches may vary back and forth and these errors cannot be detected with a standard that is right but once a day4 ,no man can compare to a certainty unless his standard is without variation1 substantially2 and ,i do not know of any way that this can be obtained so well and satisfactorily as through the means of a thoroughly good pendulum4 ,compensating seconds pendulums are1 it might be said1 the standard time measure4 ,mechanically such a pendulum is not in any way difficult of execution1 yet by far the greater portion of pendulums beating seconds are not at all accurate time measures1 as independently of their slight variations in length1 any defects in the construction or fitting of their parts are bound to have a direct effect upon the performance of the clock4 ,the average watchmaker as a mechanic has the ability to do the work properly1 but he does not fully understand or realize what is necessary1 nor appreciate the fact that little things not attended to will render useless all his efforts4 ,the first consideration in a compensated pendulum is to maintain the center of oscillation at a fixed distance from the point of suspension and it does not matter how this is accomplished4 ,so1 also1 the details of construction are of little consequence1 so long as the main points are well looked after--the perfect solidity of all parts1 with very few of them1 and the free movement of all working surfaces without play1 so that the compensating action may be constantly maintained at all times4 ,where this is not the case the sticking1 rattling1 binding or cramping of certain parts will give different rates at different times under the same variations of temperature1 according as the parts work smoothly and evenly or move only by jerks4 ,the necessary and useful parts of a pendulum are all that are really admissible in thoroughly good construction4 ,any and all pieces attached by way of ornament merely are apt to act to the prejudice of the necessary parts and should be avoided4 ,in this chapter we shall give measurements and details of construction for a number of compensated pendulums of various kinds1 as that will be the best means of arriving at a thorough understanding of the subject1 even if the reader does not desire to construct such a pendulum for his own use4 ,,principles ,,of ,,construction4--,compensation pendulums are constructed upon two distinct principles4 ,first1 those in which the bob is supported by the bottom1 resting on the adjusting screw with its entire height free to expand upward as the rod expands downward from its fixed point of suspension4 ,in this class of pendulums the error of the bob is used to counteract that of the rod and if the bob is made of sufficiently expansible metal it only remains to make the bob of sufficient height in proportion to its expansibility for one error to offset the other4 ,in the second class the attempt is made to leave out of consideration any errors caused by expansion of the bob1 by suspending it from the center1 so that its expansion downward will exactly balance its expansion upward and hence they will balance each other and may be neglected4 ,having eliminated the bob from consideration by this means we must necessarily confine our attempt at compensation to the rod in the second method4 ,the wood rod and lead bob and the mercurial pendulums are examples of the first-class and the wood rod with brass sleeve having a nut at the bottom and reaching to the center of the iron bob and the common gridiron1 or compound tubular rod1 or compound bar of steel and brass1 or steel and zinc1 are examples of the second class4 ,,wood ,,rod ,,and ,,zinc ,,bob4--,we will suppose that we have one of the ,swiss imitation gridiron pendulums which we want to discard1 while retaining the case and movement4 ,as these cases are wide and generally fitted with twelve-inch dials1 we shall have about twenty inches inside our case and we may therefore use a large bob1 lens-shaped1 made of cast zinc1 polished and lacquered to look like brass4 ,the bobs in such imitation gridiron pendulums are generally about thirteen inches in diameter and swing about five inches 7two and a half inches each side74 ,the pendulums are generally light1 convex in front and flattened at the rear1 and the entire pendulum measures about #ef inches from the point of suspension to the lower end of the adjusting screw4 ,we will also suppose that we desire to change the appearance of the clock as little as possible1 while improving its rate4 ,this will mean that we desire to retain a lens-shaped bob of about the same size as the one we are going to remove4 ,we shall first need to know the total length of our pendulum1 so that we can calculate the expansion of the rod4 ,a seconds pendulum measures #ci4b inches from the point in the suspension spring at the lower edge of the chops to the center of oscillation4 ,with a lens-shaped bob the center of gravity will be practically at the center of the bob1 if we use a light wooden rod and a steel adjusting screw and brass nut1 as these metal parts1 although short1 will be heavy enough to nearly balance the suspension spring and that portion of the rod which is above the center4 ,we shall also gain a little in balance if we leave the steel screw long enough to act as an index over the degree plate1 in the case1 at the bottom of the pendulum1 by stripping the thread and turning the end to a taper an inch or so in length4 ,we shall only be able to use one-half of the expansion upwards of our bob1 because the centers of gravity and oscillation will be practically together at the center of the bob4 ,we shall find the center of gravity easily by balancing the pendulum on a knife edge and thus we will be able to make an exceedingly close guess at the center of oscillation4 ,now1 looking over our data1 we find that we have a suspension spring of steel1 then some wood and steel again at the other end4 ,we shall need about one inch of suspension spring4 ,the spring will1 of course1 be longer than one inch1 but we shall hold it in iron chops and the expansion of the chops will equal that of the spring between them1 so that only the free part of the spring need be considered4 ,now from the adjusting screw1 where it leaves the last pin through the wood1 to the middle position of the rating nut will be about one inch1 so we shall have two inches of steel to consider in our figures of expansion4 ,now to get the length of the rod4 ,we want to keep our bob about the size of the other1 so we will try #ad inches diameter1 as half of this is an even number and makes easy figuring in our trials4 #ci4b inches1 plus #g 7half the diameter of the bob7 gives us #df4b inches2 now we have an inch of adjustment in our screw1 so we can discard the 4#b2 this leaves us #df inches of wood and steel for which we must get the expansion4 ,wood expands 4#jjjd of its length between #cb and #bab ,f4 ,steel expands 4#jjaa of its length between #cb and #bab ,f4 ,lead expands 4#jjbh of its length between #cb and #bab ,f4 ,brass expands 4#jjbj of its length between #cb and #bab ,f4 ,zinc expands 4#jjbh of its length between #cb and #bab ,f4 ,tin expands 4#jjba of its length between #cb and #bab ,f4 ,antimony expands 4#jjaa of its length between #cb and #bab ,f4 ,total length of pendulum to adjusting nut #df inches4 ,total length of steel to adjusting nut #b inches4 ,total length of wood to adjusting nut #dd inches4 4#jjaa #b 4#jjbb inch1 expansion of our steel4 4#jjjd #dd 4#jagf inch1 expansion of our wood4 -------- 4#jaih total expansion of rod4 ,we have #g inches as half the diameter of our bob 4#jaih #g 4#jjbh1 _/1 which we find from our tables is very close to the expansion of zinc1 so we will make the bob of that metal4 ,now let us check back2 the upward expansion of #g inches of zinc equals 4#jjbh #g 4#jaif inch1 as against 4#jaih inch downward expansion of the rod4 ,this gives us a total difference of 4#jjjb inch between #cb and #bab or a range of #ahj ,f4 ,this is a difference of 4#jjja inch for #ij of temperature and is closer than most pendulums ever get4 ,the above figures are for dry1 clear white pine1 well baked and shellacked1 with steel of average expansion1 and zinc of new metal1 melted and cast without the admixtures of other metals or the formation of oxide4 ,the presence of tin1 lead1 antimony and other admixtures in the zinc would of course change the results secured2 so also will there be a slight difference in the expansion of the rod if other woods are used4 ,still the jeweler can from the above get a very close approximation4 ,illustration3 ,fig4 #e4 ,zinc bob and wood rod to replace imitation gridiron pendulum4 ,such a bob1 #ad inches diameter and #a4e inches thick1 alike on both sides1 with an oval hole #a 4#e inches through its center1 see ,fig4 #e1 would weigh about #cj to #cb pounds1 and would have to be hung from a cast iron bracket1 ,fig4 #f1 bolted through the clock case to the wall behind it1 so as to get a steady rate4 ,it would be nearly constant1 as the metal is spread out so as to be quickly affected by temperature2 and the shape would hold it well in its plane of oscillation1 if both sides were of exactly the same curvature1 while the weight would overcome minor disturbances due to vibration of the building4 ,it would require a little heavier suspension spring1 in order to be isochronous in the long and short arcs and this thickening of the spring would need the addition of from one and a half to two pounds more of driving weight4 ,illustration3 ,fig4 #f4 ,cast iron bracket for heavy pendulums and movements4 ,if so heavy a pendulum is deemed undesirable1 the bob would have to be made of cylindrical form1 retaining the height1 as necessary to compensation1 and varying the diameter of the cylinder to suit the weight desired4 ,illustration3 ,fig4 #g4 ,wood rod and lead bob4 ,fig4 #h4 ,bob of metal casing filled with shot4 ,,wood ,,rod ,,and ,,lead ,,bob4--,the wood should be clear1 straight-grained and thoroughly dried1 then given several coats of shellac varnish1 well baked on4 ,it may be either flat1 oval or round in section1 but is generally made round because the brass cap at the upper end1 the lining for the crutch1 and the ferrule for the adjusting screw at the lower end may then be readily made from tubing4 ,for pendulums smaller than one second1 the wood is generally hard1 as it gives a firmer attachment of the metal parts4 ,inches4 ,length1 top of suspension spring to bottom of bob #dd4e ,length to bottom of nut #de4be ,diameter of bob #b4j ,length of bob #aj4e ,weight of bob1 #h lbs4 ,acting length of suspension spring #a4j ,width of spring 4#de ,thickness 4#jjh ,diameter of rod 4#e ,the top of the rod should have a brass collar fixed on it by riveting through the rod and it should extend down the rod about three inches1 so as to make a firm support for the slit to receive the lower clip of the suspension spring4 ,the lower end should have a slit or a round hole drilled longitudinally three inches up the rod to receive the upper end of the adjusting screw and this should also fit snugly and be well pinned or riveted in place4 ,see ,fig4 #g4 ,a piece of thin brass tube about one inch in length is fitted over the rod where the crutch works4 ,in casting zinc and lead bobs1 especially those of lens-shapes1 the jeweler should not attempt to do the work himself1 but should go to a pattern maker1 explain carefully just what is wanted and have a pattern made1 as such patterns must be larger than the casting in order to take care of the shrinkage due to cooling the molten metal4 ,it will also be better to use an iron core1 well coated with graphite when casting1 as the core can be made smooth throughout and the exact shape of the pendulum rod1 and there will then be no work to be done on the hole when the casting is made4 ,the natural shrinkage of the metal on cooling will free the core1 which can be easily driven out when the metal is cold and it will then leave a smooth1 well shaped hole to which the rod can be fitted to work easily1 but without shake4 ,lens-shaped bobs1 particularly1 should be cast flat1 with register pins on the flask1 so as to get both sides central with the hole1 and be cast with a deep riser large enough to put considerable pressure of melted metal on the casting until it is chilled1 so as to get a sound casting2 it should be allowed to remain in the sand until thoroughly cold1 for the same reason1 as if cooled quickly the bob will have internal stresses which are liable to adjust themselves sometime after the pendulum is in the clock and thus upset the rate until such interior disturbances have ceased4 ,cylinders may be cast in a length of steel tubing1 using a round steel core and driven out when cold4 ,if using oval or flat rods of wood1 the adjusting screw should be flattened for about three inches at its upper end1 wide enough to conform to the width of the rod2 then saw a slot in the center of the rod1 wide and deep enough to just fit the flattened part of the screw2 heat the screw and apply shellac or lathe wax and press it firmly into the slot with the center of the screw in line with the center of the rod2 after the wax is cold select a drill of the same size as the rivet wire2 drill and rivet snugly through the rod1 smooth everything carefully and the job is complete4 ,if by accident you have got the rod too small for the hole1 so that there is any play1 give the rod another coat of shellac varnish and after drying thoroughly1 sand paper it down until it will fit properly4 ,round rods may be treated in the same manner1 but it is usual to drill a round hole in such a rod to just fit the wire1 then insert and rivet as before after the wax is cold1 finishing with a ferrule or cap of brass at the end of the rod4 ,the slot for the suspension spring is fitted to the upper end of the rod in the same manner4 ,,pendulum ,,with ,,shot4--,still another method of making a compensating pendulum1 which gives a lighter pendulum1 is to make a case of light brass or steel tubing of about three inches diameter4 ,fig4 #h1 with a bottom and top of equal weight1 so as to keep the center of oscillation about the center of gravity1 for convenience in working4 ,the bottom may be turned to a close fit1 and soldered1 pinned1 or riveted into the tube4 ,it is pierced at its center and another tube of the same material as the outer tube1 with an internal diameter which closely fits the pendulum rod is soldered or riveted into the center of the bottom1 both bottom and top being pierced for its admission and the other parts fitted as previously described4 ,the length of the case or canister should be about #aa4e inches so as to give room for a column of shot of #aj4e inches 7the normal compensating height for lead7 and still leave room for correction4 ,make a tubular case for the driving weight also and then we have a flexible system4 ,if it is necessary to add or subtract weight to obtain the proper arcs of oscillation of the pendulum1 it can be readily done by adding to or taking from the shot in the weight case4 ,fill the pendulum to #aj4e inches with ordinary sportsmen's shot and try it for rate4 ,if it gains in heat and loses in cold it is over-compensated and shot must be taken from it4 ,if it loses in heat and gains in cold it is under-compensated and shot should be added4 ,the methods of calculation were given in full in describing the zinc pendulum and hence need not be repeated here1 but attention should be called to the fact that there are three materials here1 wood1 steel or brass and lead and each should be figured separately so that the last two may just counterbalance the first4 ,if the case is made light throughout the effect upon the center of oscillation will be inappreciable as compared with that of the lead1 but if made heavier than need be1 it will exert a marked influence1 particularly if its highest portion 7the cover7 be heavy1 as we then have the effect of a shifting weight high up on the pendulum rod4 ,if made of thin steel throughout and nickel plated1 we shall have a light and handsome case for our bob4 ,if this is not practicable1 or if the color of brass be preferred1 it may be made of that material4 ,the following table of weights will be of use in making calculations for a pendulum or for clock weights4 ,weight of ,lead1 ,zinc and ,cast ,iron ,cylinders ,one-,half ,inch ,long4 ----------------------------------- ,weight in ,pounds4 ,diameter ---------------------- in ,inches4 ,lead ,zinc ,iron --------------------------------- 4#be 4#jbj 4#jab 4#jab 4#e 4#jhj 4#jdi 4#jej 4#ge 4#ahj 4#aaa 4#aad #a4 4#cba 4#aih 4#bjd #a4be 4#ejc 4#caj 4#cai #a4e 4#gbd 4#ddg 4#dei #a4ge 4#ihd 4#fjg 4#fbd #b4 #a4bhg 4#gid 4#haf #b4be #a4fcj #a4jje #a4jcc #b4e #b4jji #b4bci #a4bgd #b4ge #b4dcd #a4ejb #a4edd #c4 #b4hig #a4ghh #a4hcg #c4be #c4djj #b4jih #b4aef #c4e #c4idd #b4dcd #b4dia #c4ge #d4ea #b4ghc #b4hfe #d4 #e4adi #c4agg #c4bfe #d4be #e4hac #c4ehg #c4fhf #d4e #f4eai #c4ibb #d4acd #d4ge #g4bfe #d4dhc #d4fjg #e4 #h4jdh #d4iff #e4ajc #e4be #h4hgb #e4dgd #e4fbf #e4e #i4gcg #f4jjh #e4age #e4ge #aj4fdc #f4efg #f4gdi #f4 #aa4eij #g4aeb #g4cej --------------------------------- ,example3--,required1 the weight of a lead pendulum bob1 #c inches diameter1 #i inches long1 which has a hole through it 4#ge inch in diameter4 ,the weight of a lead cylinder #c inches diameter in the table is #b4hig1 which multiplied by #i 7the length given7 #bf4jg lbs4 ,then the weight in the table of a cylinder 4#ge inch diameter is 4#ah and 4#ah #i #a4fb lbs4 ,and #bf4jg - #a4fb #bd4de1 the weight required in lbs4 ,,auxiliary ,,weights4--,if for any reason our pendulum does not turn out with a rating as calculated and we find after getting it to time that it is over-compensated1 it is a comparatively simple matter to turn off a portion from the bottom of a solid bob4 ,by doing this in very small portions at a time and then testing carefully for heat and cold every time any amount has been removed1 we shall in the course of a few weeks arrive at a close approximation to compensation1 at least as close as the ordinary standards available to the jeweler will permit4 ,this is a matter of weeks1 because if the pendulum is being rated by the standard time which is telegraphed over the country daily at noon1 the jeweler1 as soon as he gets his pendulum nearly right1 will begin to discover variations in the noon signal of from 4#b to #e seconds on successive days4 ,then it becomes a matter of averages and reasoning1 thus3 ,if the pendulum beats to time on the first1 second1 third1 fifth and seventh days1 it follows that the signal was incorrect--slow or fast--on the fourth and sixth days4 ,if the pendulum shows a gain of one second a week on the majority of the days1 the observation must be continued without changing the pendulum for another week4 ,if the pendulum shows two seconds gain at the end of this time1 we have two things to consider4 ,is the length right1 or is the pendulum not fully compensated8 ,we cannot answer the second query without a record of the temperature variations during the period of observations4 ,to get the temperature record we shall require a set of maximum and minimum thermometers in our clock case4 ,they consist of mercurial thermometer tubes on the ordinary ,fahrenheit scales1 but with a marker of colored wood or metal resting on the upper end of the column of mercury in the tube4 ,the tube is not hung vertically1 but is placed in an inclined position so that the mark will stay where it is pushed by the column of mercury4 ,thus if the temperature rises during the day to #hd degrees the mark in the maximum thermometer will be found resting in the tube at #hd whether the mercury is there when the reading is taken or not4 ,similarly1 if the temperature has dropped during the night to #dj1 the mark in the minimum thermometer will be found at #dj1 although the temperature may be #gj when the reading is taken4 ,after reading1 the thermometers are shaken to bring the marks back to the top of the column of mercury and the thermometers are then restored to their positions1 ready for another reading on the following day4 ,these records should be set down on a sheet every day at noon in columns giving date1 rate1 plus or minus1 maximum1 minimum1 average temperature and remarks as to regulation1 etc41 and with these data to guide us we shall be in a position to determine whether to move the rating nut or not4 ,if the temperature has been fairly constant we can get a closer rate by moving the nut and continuing the observations4 ,if the temperature has been increasing steadily and our pendulum has been gaining steadily it is probably over-compensated and the bob should be shortened a trifle and the observations renewed4 ,it is best to 8make haste slowly0 in such a matter4 ,first bring the pendulum to time in a constant temperature2 that will take care of its proper length4 ,then allow the temperature to vary naturally and note the results4 ,if the pendulum is under-compensated1 so that the bob is too short to take care of the expansion of the rod1 auxiliary weights of zinc in the shape of washers 7or short cylinders7 are placed between the bottom of the bob and the rating nut4 ,this of course makes necessary a new adjustment and another course of observations all around1 but it will readily be seen that it places a length of expansible metal between the nut and the center of oscillation and thus makes up for the deficiency of expansion of the bob4 ,zinc is generally chosen on account of its high rate of expansion1 but brass1 aluminum and other metals are also used4 ,it is best to use one thick washer1 rather than a number of thinner ones1 as it is important to keep the construction as solid at this point as possible4 ,,top ,,weights4--,after bringing the pendulum as close as possible by the compensation and the rating nuts1 astronomers and others requiring exact time get a trifle closer rating by the use of top weights4 ,these are generally ,u-shaped pieces of thin metal which are slipped on the rod above the bob without stopping the pendulum4 ,they raise the center of oscillation by adding to the height of the bob when they are put on1 or lower it when they are removed1 but they are never resorted to until long after the pendulum is closer to time than the jeweler can get with his limited standards of comparison4 ,they are mentioned here simply that their use may be understood when they may be encountered in cleaning siderial clocks4 ,mercurial pendulums also belong to the class of compensation by expansion of the bobs1 but they are so numerous and so different that they will be considered separately1 later on4 ,,compensated ,,pendulum ,,rods4--,we will now consider the second class1 that in which an attempt is made to obtain a pendulum rod of unvarying length4 ,the oldest form of compensated rod is undoubtedly the gridiron of either nine1 five or three rods4 ,as originally made it was an accurate but expensive proposition1 as the coefficients of expansion of the brass or zinc and iron or steel had all to be determined individually for each pendulum4 ,each rod had to be sized accurately1 or if this was not done1 then each rod had to be fitted carefully to each hole in the cross bars so as to move freely1 without shake4 ,the rods were spread out for two purposes1 to impress the public and to secure uniform and speedy action in changes of temperature4 ,the weight1 which increased rapidly with the increase of diameter of the rod1 made a long and large seconds pendulum1 some of them measuring as much as sixty-two inches in length1 and needing a large bob to look in proportion4 ,various attempts were made to ornament the great expanse of the gridiron1 harps1 wreaths and other forms in pierced metal being screwed to the bars4 ,the next advance was in substituting tubes for rods in the gridiron1 securing an apparently large rod that was at the same time stiff and light4 ,then came the era of imitation1 in which the rods were made of all brass1 the imitation steel portion being nickel plated4 ,with the development of plating they were still further cheapened by being made of steel1 with the supposedly brass rods plated with brass and the steel ones with nickel4 ,thousands of such pendulums are in use to-day2 they have the rods riveted to the cross-pieces and are simply steel rods1 subject to change of length with every change in temperature4 ,it does no harm to ornament such pendulums1 as the rods themselves are merely ornaments1 usually all of one metal1 plated to change the color4 ,as three rods were all that were necessary1 the clockmaker who desired a pendulum that was compensated soon found his most easily made rod consisted of a zinc bar1 wide1 thin and flat1 placed between two steel parts1 like the meat and bread of a sandwich4 ,this gives a flat and apparently solid rod of metal which if polished gives a pleasing appearance1 and combines accurate performance with cheapness of construction1 so that any watchmaker may make it himself1 without expensive tools4 ,illustration3 ,fig4 #i4 ,pendulum with compensated rod of steel and zinc4 ,a1 the lens-shaped bob2 ,t ,p1 the total length of the compensating part4 ,r1 the upper round part of rod4 ,the side showing the heads of the screws is the face side and is finished4 ,the screws #a1 #b1 #c1 #d hold the three pieces from separating1 but do not confine the front and middle sections in their lengthwise expansion along the rod1 but are screwed into the back iron section1 while the holes in the other two sections are slotted smaller than the screw heads4 ,the holes at the lower extreme of combination #e1 #f1 #g1 #h1 #i are for adjustments in effecting a compensation4 ,the pin at #aj is the steel adjusting pin1 and is only tight in the front bar and zinc bars1 being loose in the back bar4 ,o and ,p show the angles in the back rod1 ,t shows the angle in the rod at the top1 m shows the pin as placed in the iron and zinc sections where they have been soldered as described4 h shows the regulating nut carried by the tube1 as described1 and terminating in the nut ,d4 l and i show the screw of #cf threads4 ,the nut ,d is to be divided on its edge into #cj divisions4 n is the angle of the back bar to which zinc is soldered4 ,,flat ,,compensated ,,rod4--,one of the most easily made zinc and iron compensating pendulums1 shown in detail in ,fig4 #i1 is as follows3 ,a lead or iron bob1 lens-shaped1 that is1 convex equally on each side1 #i inches diameter and an inch and one-quarter thick at the center4 ,a hole to be made straight through its diameter inch4 ,one-half through the diameter this hole is to be enlarged to inch diameter4 ,this will make the hole for half of its length inch and the remaining half inch diameter4 ,the hole must have a thin tube1 just fitting it1 and #e inches long4 ,at one end of this tube is soldered in a nut1 with a hole tapped with a tap of thirty-six threads to the inch1 and inch diameter1 and at the other end of the tube is soldered a collar or disc one inch diameter1 which is to be divided into thirty divisions1 for regulating purposes1 as will be described later on4 ,the whole forms a nut into which the rod screws1 and the tube allows the nut to be pushed up to the center of the diameter of the bob1 through the large hole1 and the nut can be operated then by means of the disc at its lower end4 ,the rod1 of flat iron1 is in two sections1 as follows3 ,that section which enters the bob and terminates in the regulating screw is flat for twenty-six inches1 and then rounded to inch for six inches1 and a screw cut on its end for two inches1 to fit the thread in the nut4 ,the upper end of this section is then to be bent at a right angle1 flatwise4 ,this angle piece will be long enough if only _/ inch long1 so that it covers the thickness of the zinc center rod4 ,the zinc center rod is a bar of the metal1 hammered or rolled1 #be inches long1 _/ inch thick1 and inch wide1 and comes up against the angle piece bent on the flat part of the lower section of the rod4 ,now the upper section of the rod may be an exact duplicate of the lower section1 with the flat part only a little longer than the zinc bar1 say inch1 and the angle turned on the end1 as previously described4 ,the balance of the bar may be forged into a rod of _/ inch diameter4 ,as has been stated1 the zinc bar is placed against the angle piece bent on the upper end of the lower section of the rod1 ,p1 n1 ,fig4 #i1 and pins must be put through this angle piece into the end of the zinc bar1 to hold it in close contact with the iron bar4 ,the upper section of the rod is now to be laid on the opposite side of the zinc bar1 with its angle at the other end of the zinc1 but not in contact with it1 say _/ inch left between the angle and the zinc bar4 ,now all is ready to clamp together--the two flat iron bars with the zinc between them4 ,after clamping1 taking care to have the pinned end of the zinc in contact with the angle and the free1 or lower end1 removed from the other angle about _/ inch1 three screws should be put through all three bars1 with their heads all on the side selected for the front1 and one screw may be an inch from the top1 another #c inches from the bottom1 and one-half way between the two first mentioned4 ,now the rod is complete in its composite form1 and there is left only the little detail to attend to4 ,two flat bars1 with their ends angled in one case and rounded in the other into rods of given diameter1 confining between them1 as described1 a flat bar of wrought zinc of stated length and of the same thickness and width as the iron bars1 comprises the active or compensating elements of the pendulum's rod4 ,the screws that are put through the three bars are each to pass through the front iron bar1 without threads in the bar1 and only the back iron bar is to have the holes tapped1 fitting the screws4 ,all the corresponding holes in the zinc are to be reamed a little larger than the diameter of the screws1 and to be freed lengthwise of the bar1 to allow of the bar's contracting and expanding without being confined in this action by the screws4 ,at the lower or free end of the zinc bar are to be holes carried clear through all three bars1 while the combination is held firmly together by the screws4 ,these holes are to start at inch from the end of the zinc1 and each carried straight through all three bars1 and then broached true and a steel pin made to accurately fit them from the front side4 ,these holes may be from three to five in number1 extending up to a safe distance from the lower screw4 ,the holes in the back bar1 after boring1 are to be reamed larger than those in the front bar and zinc bar4 ,these holes and the pin serve for adjusting the compensation4 ,the pin holds the front bar and zinc from slipping1 or moving past one another at the point pinned1 and also allows the back bar to be free of the pin1 and not under the influence of the two front bars4 ,the upper end of the second iron section is1 as has been mentioned1 forged into a round rod about _/ inch diameter1 and this rod or upper end is to receive the pendulum suspension spring1 which may be one single spring1 or a compound spring1 as preferred4 ,now that the pendulum is all ready to balance on the knife edge1 proceed as in the case of the simple pendulum1 and ascertain at what point up the rod the spring must be placed4 ,in this pendulum the rod will be heavier in proportion than the wood rod was to its bob1 and the center of gravity of the whole will be found higher up in the bob4 ,however1 wherever in the bob the center of gravity is found1 that is the starting point to measure from to find the total length of the rod1 and the point for the spring4 ,the heavier the rod is in relation to the bob1 the higher will the center of gravity of the whole rise in the bob1 and the greater will be the total length of the entire pendulum4 ,in getting up a rod of the kind just described1 the main item is to get the parts all so arranged that there will be very little settling of the joints in contact1 particularly those which sustain the weight of the bob and the whole dead weight of the pendulum4 ,the nut in the center of the pendulum holds the weight of the bob only1 but it should fit against the shoulder formed for the purpose by the juncture of the two holes1 and the face of the nut should be turned true and flat1 so that there may not be any uneven motion1 and only the one imparted by the progressive one of the threads4 ,when this nut is put to its place for the last time1 and after all is finished1 there should be a little tallow put on to the face of the nut just where it comes to a seat against the shoulder of the bob1 as this shoulder being not very well finished1 the two surfaces coming in contact1 if left dry1 might cut and tear each other1 and help to make the nut's action slightly unsteady and unreliable4 ,a finished washer can be driven into this lower hole up to the center1 friction-tight1 and serve as a reliable and finished seat for the nut4 ,in reality1 the zinc at the point of contact1 where pinned to the angle piece at the top of the lower section1 is the point of greatest importance in the whole combination1 and if the joint between the angle and the end of the zinc bar is soldered with soft solder1 the result will be that of greater certainty in the maintenance of a steady rate4 ,this joint just mentioned can be soldered as follows3 ,file the end of the zinc and the inside surface of the angle until they fit so that no appreciable space is left between them4 ,then1 with a soldering iron1 tin the end of the zinc thoroughly and evenly1 and then put into the holes already made the two steady pins4 ,now tin in the same manner the surface of the angle1 and see that the holes are free of solder1 so that the zinc bar will go to its place easily2 then between the zinc and the iron1 place a piece of thin writing paper1 so that the flat surfaces of the zinc and iron may not become soldered4 ,set the iron bar upright on a piece of charcoal1 and secure it in this position from any danger of falling1 and then put the zinc to its place and see that the pins enter and that the paper is between the surfaces1 as described4 ,put the screws into their places1 and screw down on the zinc just enough to hold it in contact with the iron bar1 but not so tight that the zinc will not readily move down and rest firmly on the angle4 ,put a little soldering fluid on the tinned joint1 and blow with a blow pipe against the iron bar 7not touching the zinc with the flame74 ,when the solder in the joint begins to flow1 press the zinc down in close contact with the angle1 and then cool gradually1 and if all the points described have been attended to the joint will be solidly soldered1 and the two bars will be as one solid bar bent against itself4 ,the tinning leaves surplus solder on the surfaces sufficient to make a solid joint1 and to allow some to flow into the pin holes and also solder the pin to avoid any danger of getting loose in after time1 and helps make a much stronger joint4 ,at the time the solder is melted the zinc is sufficiently heated to become quite malleable1 and care must be taken not to force it down against the angle in making the joint1 or it may be distorted and ruined at the joint4 ,if carefully done the result will be perfect4 ,the paper between the surfaces burns1 and is got rid of in washing to remove the soldering fluid4 ,soda or ammonia will help to remove all traces of the fluid4 ,however1 it is best1 as a last operation1 to put the joint in alcohol for a minute4 ,this soldering makes the lower section and the zinc practically one piece and without loose joint1 and the next joint is that made by the pin pinning the outside bar and the zinc together4 ,this is necessarily formed this way1 as in this stage of the operation we do not know just what length the zinc bar will be to exactly compensate for the expansion and contraction of the balance of the pendulum4 ,by the changing of the pin into the different holes1 #e1 #f1 #g1 #h1 #i1 #aj1 ,fig4 #i1 the zinc is made relatively longer or shorter1 and so a compensation is arrived at in time after the clock has been running4 ,after it is definitely settled where the pin will remain to secure the compensation of the rod1 then that hole can have a screw put in to match the three upper ones4 ,this screw must be tapped into the front bar and the zinc1 and be very free in the back bar to allow of its expansion4 ,it is supposed that in this example given of a zinc and steel compensation seconds pendulum that there has been due allowance made in the lengths of the several bars to allow for adjustment to temperature by the movements of the pin along the course of the several holes described1 but the zinc is a very uncertain element1 and its ultimate action is largely influenced by its treatment after being cast4 ,differences of working cast zinc under the hammer or rolls produce wide differences practically1 and therefore materially change the results in its combination with iron in their relative expansive action4 ,wrought zinc can be obtained of any of the brass plate factories1 of any dimensions required1 and will be found to be satisfactory for the purpose in hand4 ,the adjusting pin should be well fitted to the holes in the front iron bar1 and also fit the corresponding ones in the zinc bar closely1 and if the holes are reamed smooth and true with an ,english clock broach1 then the pin will be slightly tapering and fit the iron hole perfectly solid4 ,after one pair of these holes have been reamed1 fit the pin and drive it in place perfectly firm1 and then with the broach ream all the remaining holes to just the same diameter1 and then the pin will move along from one set of holes to another with mechanically accurate results4 ,otherwise1 if poorly fitted1 the full effect would not be obtained from the compensating action in making changes in the pin from one set of holes to another4 ,this pin1 if made of cast steel1 hardened and drawn to a blue1 will on the whole be a very good device mechanically4 ,many means are used to effect the adjustments for compensation1 of more or less value1 but whatever the means used1 it must be kept in mind that extra care must be taken to have the mechanical execution first class1 as on this very much depends the steady rate of the pendulum in after time4 ,,tubular ,,compensated ,,rods4--,there are tubular pendulums in the market which have a screw sleeve at the top of the zinc element1 and by this means the adjustments are effected1 and this is thought to be a very accurate mechanism4 ,the most common form of zinc and iron compensation is where the zinc is a tube combined with one iron tube and a central rod1 as shown in ,figs4 #aj1 #aa1 #ab4 ,the rod is the center piece1 the zinc tube next1 followed by the iron tube enveloping both4 ,the relative lengths may be the same as those just given in the foregoing example with the compensating elements flat4 ,the relative lengths of the several members will be virtually the same in both combinations4 ,,tubular ,,compensation ,,with ,,aluminum4--,the pendulum as seen by an observer appears to him as being a simple single rod pendulum4 ,figs4 #aj and #ab are front and side views2 ,fig4 #aa is an enlarged view of its parts1 the upper being a sectional view4 ,its principal features are3 ,the steel rod ,s1 ,fig4 #aa1 #d mm4 in diameter1 having at its upper end a hook for fastening to the suspension spring in the usual way2 the lower end has a pivot carrying the bushing1 ,t1 which solidly connects the steel rod1 ,s1 with the aluminum tube1 ,a1 the latter being #aj mm4 in diameter and its sides #a4e mm4 in thickness of the wall4 ,the upper end of the aluminum tube is very close to the pendulum hook and is also provided with a bushing1 ,p1 ,fig4 #aa4 ,this bushing is permanently connected at the upper end of the aluminum tube with a steel tube1 ,r1 #af mm4 in diameter and #a mm4 in thickness4 ,the outer steel tube is the only one that is visible and it supports the bob1 the lower part being furnished with a fine thread on which the regulating nut1 ,o1 is movable1 at the center of the bob4 ,for securing a central alignment of the steel rod1 ,s1 at its lowest part1 where it is pivoted1 a bushing1 ,m1 ,fig4 #aa1 is screwed into the steel tube1 ,r4 ,the lower end of the steel tube1 ,r1 projects considerably below the lenticular bob 7compare ,figs4 #aj and #ab72 and is also provided with a thread and regulating weight1 ,g 7,figs4 #aj and #ab71 of #ajj grammes in weight1 which is only used in the fine regulation of small variations from correct time4 ,the steel tube is open at the bottom and the index at its lower end is fastened to a bridge4 ,furthermore all three of the bushings1 ,p1 ,t and ,m1 have each three radial cuts1 which will permit the surrounding air to act equally and at the same time on the steel rod1 ,s1 the aluminum tube4 ,a1 and the steel tube1 ,r1 and as the steel tube1 ,r1 is open at its lower end1 and as there is also a certain amount of space between the tubes1 the steel rod1 and the radial openings in the bushings1 there will be a draught of air passing through them1 which will allow the thin-walled tubes and thin steel rod to promptly and equally adapt themselves to the temperature of the air4 ,illustration3 ,fig4 #aj4 ,fig4 #aa4 ,fig4 #ab4 ,the lenticular pendulum bob has a diameter of #bd cm41 and is made of red brass4 ,the bob is supported at its center by the regulating nut1 ,o1 ,figs4 #aj and #ab4 ,that the bob may not turn on the cylindrical pendulum rod1 the latter is provided with a longitudinal groove and working therein are the ends of two shoulder screws which are placed on the back of the bob above and below the regulating nut1 ,o2 and thus properly controlling its movements4 ,from the foregoing description the action of the compensation is readily explained4 ,for the purpose of illustration of its action we will accept the fact that there has been a sudden rise in temperature4 ,the steel rod1 ,s1 and the tube1 ,r1 will lengthen in a downward direction 7including the suspension spring and the pendulum hook71 conversely the aluminum tube1 ,a1 which is fastened to the steel rod at one end and the steel tube at the other1 will lengthen in an upward direction and thus equalize the expansion of the tube1 ,r1 and rod1 ,s4 ,as the coefficients of expansion of steel and aluminum are approximately at the ratio of #a3b4jcac we find that with such a pendulum construction--accurate calculations presumed--we shall have a complete and exact coincidence in its compensation2 in other words1 the center of oscillation of the pendulum will be under all conditions at the same distance from the bending point of the suspension spring4 ,this style of pendulum is made for astronomical clocks in ,europe and is furnished in two qualities4 ,in the best quality1 the tubes1 steel rod1 and the bob are all separately and carefully tested as to their expansion1 and their coefficients of expansion fully determined in a laboratory2 the bushings1 ,p and ,m1 are jeweled1 all parts being accurately and finely finished4 ,in the second quality the pendulum is constructed on a general calculation and finished in a more simple manner without impairing its ultimate efficiency4 ,at the upper part of the steel tube1 ,r1 there is a funnel-shaped piece 7omitted in the drawing7 in which are placed small lead and aluminum balls for the final regulation of the pendulum without stopping it4 ,the regulation of this pendulum is effected in three ways3 #a4 ,the preliminary or coarse regulation by turning the regulating nut1 ,o1 and so raising or lowering the bob4 #b4 ,the finer regulation by turning the #ajj grammes weight1 g1 having the shape of a nut and turning on the threaded part of the tube1 ,r4 #c4 ,the precision regulation is effected by placing small lead or aluminum balls in a small funnel-shaped receptacle attached to the upper part of the tube1 ,r1 or by removing them therefrom4 ,it will readily be seen that this form of pendulum can be used with zinc or brass instead of aluminum1 by altering the lengths of the inner rod and the compensating tube to suit the expansion of the metal it is decided to use2 also that alterations in length may be made by screwing the bushings in or out1 provided that the tube be long enough in the first place4 ,after securing the right position the bushings should have pins driven into them through the tube1 in order to prevent further shifting4 ,,chapter ,,iv4 ,,the ,,construction ,,of ,,mercurial ,,pendulums4 ,owing to the difficulty of calculating the expansive ratios of metal which 7particularly with brass and zinc7 vary slightly with differences of manufacture1 the manufacture of compensated pendulums from metal rods cannot be reduced to cutting up so many pieces and assembling them from calculations made previously1 so that each must be separately built and tested4 ,while this is not a great draw-back to the jeweler who wants to make himself a pendulum1 it becomes a serious difficulty to a manufacturer1 and hence a cheaper combination had to be devised to prevent the cost of compensated pendulums from seriously interfering with their use4 ,the result was the pendulum composed of a steel rod and a quantity of mercury1 the latter forming the principal weight for the bob and being contained in steel or glass jars1 or jars of cast iron for the heavier pendulums4 ,other metals will not serve the purpose1 as they are corroded by the mercury1 become rotten and lose their contents4 ,mercury has one deficiency which1 however1 is not serious1 except for the severe conditions of astronomical observatories4 ,it will oxidize after long exposure to the air1 when it must be strained and a fresh quantity of metal added and the compensation freshly adjusted4 ,to an astronomer this is a serious objection1 as it may interfere with his work for a month1 but to the jeweler this is of little moment as the rates he demands will not be seriously affected for about ten years1 if the jars are tightly covered4 ,to construct a reliable gridiron pendulum would cost about fifty dollars while a mercurial pendulum can be well made and compensated for about twenty-five dollars1 hence the popularity of the latter form4 ,zinc will lengthen under severe variations of temperature as the following will show3 ,zinc has a decided objectionable quality in its crystalline structure that with temperature changes there is very unequal expansion and contraction1 and furthermore1 that these changes occur suddenly2 this often results in the blending of the zinc rod1 causing a binding to take place1 which naturally enough prevents the correct working of the compensation4 ,it is probably not very well known that zinc can change its length at one and the same temperature1 and that this peculiar quality must not be overlooked4 ,the ,u4 ,s4 ,lake ,survey1 which has under its charge the triangulation of the great lakes of the ,united ,states1 has in its possession a steel meter measure1 ,r1 #ahgf2 a metallic thermometer composed1 of a steel and zinc rod1 each being one meter in length1 marked ,m4 ,t41 #ahgfs1 and ,m4 ,t4 #ahgfz2 and four metallic thermometers1 used in connection with the base apparatus1 which likewise are made of steel and zinc rods1 each of these being four meters in length4 ,all of these rods were made by ,repsold1 of ,hamburg4 ,comparisons between these different rods show peculiar variations1 and which point to the fact that their lengths at the same degree of temperature are not constant4 ,for the purpose of determining these variations accurate investigations were undertaken4 ,the metallic thermometer ,m4 ,t4 #ahgf was removed from an observatory room having an equal temperature of about #b ,c4 and placed for one day in a temperature of #bd ,c41 and also for the same period of time in one of -#bj ,c2 it was then replaced in the observatory room1 where it remained for twenty-four hours1 and comparisons were made during the following three days with the steel thermometer #ahgf1 which had been left in the room4 ,from these observations and comparisons the following results were tabulated1 which give the mean lengths of the zinc rods of the metallic thermometer4 ,the slight variations of temperature in the observatory room were also taken into consideration in the calculations3 ,m4 ,t4 #ahgfs4 ,m4 ,t4 #ahgfz4 mm4 mm4 ,february #af-bd - #j4jjjf #j4jaeb1 previous #g days at #bd;,c ,february #be-bg - #j4jjag - #j4jjaa1 previous #a day at - #bj;,c4 ,march #b-d #j4jjje #j4jaed1 previous #a day at #bd;,c4 ,march #e-h - #j4jjeh - #j4jjbb1 previous #a day at - #bj;,c4 ,these investigations clearly indicate1 without doubt1 that the zinc rod at one and the same temperature of about #b ,c41 is #j4jah mm4 longer after having been previously heated to #bd ,c4 than when cooled before to -#bj ,c4 ,a similar but less complete examination was made with the metallic thermometer four meters in length4 ,these trials were made by that efficient officer1 ,general ,comstock1 gave the same results1 and completely prove that in zinc there are considerable thermal after-effects at work4 ,to prove that zinc is not an efficient metal for compensation pendulums when employed for the exact measurement of time1 a short calculation may be made--using the above conclusions--that a zinc rod one meter in length1 after being subjected to a difference of temperature of #dd ,c4 will alter its length #j4jah mm4 after having been brought back to its initial degree4 ,for a seconds pendulum with zinc compensation each of the zinc rods would require a length of #fd4i cm4 ,with the above computations we get a difference in length of #j4jaag mm4 at the same degree of temperature4 ,since a lengthening of the zinc rods without a suitable and contemporaneous expansion of the steel rods is synonymous with a shortening of the effectual pendulum length1 we have1 notwithstanding the compensation1 a shortening of the pendulum length of #j4jag mm41 which corresponds to a change in the daily rate of about #j4e seconds4 ,this will sufficiently prove that zinc is unquestionably not suitable for extremely accurate compensation pendulums1 and as neither is permanent under extremes of temperature the advantages of first cost and of correction of error appear to lie with the mercurial form4 ,the average mercurial compensation pendulums1 on sale in the trade are often only partially compensated1 as the mercury is nearly always deficient in quantity relatively1 and not high enough in the jar to neutralize the action of the rigid metallic elements1 composing the structure4 ,the trouble generally is that the mercury forms too small a proportion of the total weight of the pendulum bob4 ,there is a fundamental principle governing these compensating pendulums that has to be kept in mind1 and that is that one of the compensating elements is expected to just undo what the other does and so establish through the medium of physical things the condition of the ideal pendulum1 without weight or elements outside of the bob4 ,as iron and mercury1 for instance1 have a pretty fixed relative expansive ratio1 then whatever these ratios are after being found1 must be maintained in the construction of the pendulum1 or the results cannot be satisfactory4 ,first1 there are #ci4b inches of rod of steel to hold the bob between the point of suspension and the center of oscillation1 and it has been found that1 constructively1 in all the ordinary forms of these pendulums1 the height of mercury in the bob cannot usually be less than #g4e inches4 ,second1 that in all seconds pendulums the length of the metal is fixed substantially1 while the height of the mercury is a varying one1 due to the differing weights of the jars1 straps1 etc4 ,third1 the mercury1 at its minimum1 cannot with jars of ordinary weight be less in height in the jar than #g4e inches1 to effectually counteract what the #ci4b inches of iron does in the way of expanding and contracting under the same exposure4 ,whoever observes the great mass of pendulums of this description on sale and in use will find that the height of the mercury in the jar is not up to the amount given above for the least quantity that will serve under the most favorable circumstances of construction4 ,the less weight there is in the rod1 jar and frame1 the less is the height of mercury which is required2 but with most of the pendulums made in the present day for the market1 the height given cannot be cut short without impairing the quality and efficiency of the compensation4 ,any amount less will have the effect of leaving the rigid metal in the ascendancy2 or1 in other words1 the pendulum will be under compensated and leave the pendulum to feel heat and cold by raising and lowering the center of oscillation of the pendulum and hence only partly compensating4 ,a jar with only six inches in height of mercury will in round numbers only correct the temperature error about six-sevenths4 ,,calculations ,,of ,,weights4--,as to how to calculate the amount of mercury required to compensate a seconds pendulum1 the following explanation should make the matter clear to anyone having a fair knowledge of arithmetic only1 though there are several points to be considered which render it a rather more complicated process than would appear at first sight4 #ast4 ,the expansion in length of steel and cast iron1 as given in the tables 7these tables differ somewhat in the various books71 is respectively 4#jjfd and 4#jjff1 while mercury expands 4#a in bulk for the same increase of temperature4 ,if the mercury were contained in a jar which itself had no expansion in diameter1 then all its expansion would take place in height1 and in round numbers it would expand sixteen times more than steel1 and we should only require 7neglecting at present the allowance to be explained under head #c7 to make the height of the mercury--reckoned from the bottom of the jar 7inside7 to the middle of the column of mercury contained therein--one-sixteenth of the total length of the pendulum measured from the point of suspension to the bottom of the jar1 assuming that the rod and the jar are both of steel1 and that the center of oscillation is coincident with the center of the column of mercury4 ,practically in these pendulums1 the center of oscillation is almost identical with the center of the bob4 #b;d4 ,as we cannot obtain a jar having no expansion in diameter1 we must allow for such expansion as follows1 and as cast iron or steel jars of cylindrical shape are undoubtedly the best1 we will consider that material and form only4 ,as above stated1 cast iron expands 4#jjff1 so that if the original diameter of the jar be represented by #a1 its expanded diameter will be #a4jjff4 ,now the area of any circle varies as the square of its diameter1 so that before and after its expansion the areas of the jar will be in the ratio of #a to #a4jjff2 that is1 in the proportion of #a to #a4jacbdc2 or in round numbers it will be one-seventy-sixth larger in area after expansion than before4 ,it is evident that the mercury will then expand sideways1 and that its vertical rise will be diminished to the same extent4 ,deduct1 therefore1 the one-seventy-sixth from its expansion in bulk 7one-tenth7 and we get one-eleventh 7or more exactly 4#jhfgeg7 remaining4 ,this1 then1 is the actual vertical rise in the jar1 and when compared with the expansion of steel in length it will be found to be about thirteen and a half times greater 7more exactly #ac4eef74 ,the mercury1 therefore 7still neglecting head ,no4 #c71 must be thirteen and a half times shorter than the length of the pendulum1 both being measured as explained above4 ,the pendulum will probably be #dc4e inches long to the bottom of the jar2 but as about nine inches of it is cast iron1 which has a slightly greater rate of expansion than steel1 we will call the length #dd inches1 as the half inch added will make it about equivalent to a pendulum entirely of steel4 ,if the height of the mercury be obtained by dividing #dd by #ac4e1 it will be #c4be inches high to its center1 or #f4e inches high altogether2 and were it not for the following circumstance1 the pendulum would be perfectly compensated4 #c;d4 ,the mercury is the only part of the bob which expands upwards2 the jar does not rise1 its lower end being carried downward by the expansion of the rod1 which supports it4 ,in a well-designed pendulum1 the jar1 straps1 etc41 will be from one-fourth to one-third the weight of the mercury4 ,assume them to be seven pounds and twenty-eight pounds respectively2 therefore1 the total weight of the bob is thirty-five pounds2 but as it is only the mercury 7four-fifths7 of this total that rises with an increase of temperature1 we must increase the weight of the mercury in the proportion of five to four1 thus #f4e #e #d #h inches4 ,or1 what is the same thing1 we add one-fourth to the amount of mercury1 because the weight of the jar is one-fourth of that of the mercury4 ,eight and one-eighth inches is1 therefore1 the ultimate height of the mercury required to compensate the pendulum with that weight of jar4 ,if the jar had been heavier1 say one-third the weight of the mercury1 then the latter would have to be nearly #h4ge inches high4 ,if the jar be required to be of glass1 then we substitute the expansion of that material in ,no4 #b and its weight in ,no4 #c4 ,in the above method of calculating1 there are two slight elements of uncertainty3 #ast4 ,in assuming that the center of oscillation is coincident with the center of the bob2 however1 ,i should suppose that they would never be more than 4#be inch apart1 and generally much nearer4 #b;d4 ,the weight of the jar cannot well be exactly known until after it is finished 7i4 e41 bored smooth and parallel inside1 and turned outside true with the interior71 so that the exact height of the mercury cannot be easily ascertained till then4 ,i may explain that the reason 7in ,nos4 #a and #b7 we measure the mercury from the bottom to the center of the column1 is that it is its center which we wish to raise when an increase of temperature occurs1 so that the center may always be exactly the same distance from the point of suspension2 and we have seen that #c4be inches is the necessary quantity to raise it sufficiently4 ,now that center could not be the center without it had as much mercury over it as it has under it2 hence we double the #c4be and get the #f4e inches stated4 ,from the foregoing it will be seen that the average mercury pendulums are better than a plain rod1 from the fact that the mercury is free to obey the law of expansion1 and so1 to a certain degree1 does counteract the action of the balance of the metal of the pendulum1 and this with a degree of certainty that is not found in the gridiron form1 provided always that the height and amount of the mercury are correctly proportional to the total weight of the pendulum4 ,,compensating ,,mercurial ,,pendulums4--,to compensate a pendulum of this kind takes time and study4 ,the first thing to do is to place maximum and minimum thermometers in the clock case1 so that you can tell the temperature4 ,then get the rate of the clock at a given temperature4 ,for example1 say the clock gains two seconds in twenty-four hours1 the temperature being at #gj4 ,then see how much it gains when the temperature is at #hj4 ,we will say it gains two seconds more at #hj than it does when the temperature is at #gj4 ,in that case we must remove some of the mercury in order to compensate the pendulum4 ,to do this take a syringe and soak the cotton or whatever makes the suction in the syringe with vaseline4 ,the reason for doing this is that mercury is very heavy and the syringe must be air-tight before you can take any of the mercury up into it4 ,you want to remove about two pennyweights of mercury to every second the clock gains in twenty-four hours4 ,now1 after removing the mercury the clock will lose time1 because the pendulum is lighter4 ,you must then raise the ball to bring it to time4 ,you then repeat the same operation by getting the rate at #gj and #hj again and see if it gains4 ,when the temperature rises1 if the pendulum still gains1 you must remove more mercury2 but if it should lose time when the temperature rises you have taken out too much mercury and you must replace some4 ,continue this operation until the pendulum has the same rate1 whether the temperature is high or low1 raising the bob when you take out mercury to bring it to time1 and lowering the bob when you put mercury in to bring it to time4 ,to compensate a pendulum takes time and study of the clock1 but if you follow out these instructions you will succeed in getting the clock to run regularly in both summer and winter4 ,besides the oxidation1 which is an admitted fault1 there are two theoretical questions which have to do with construction in deciding between the metallic and mercurial forms of compensation4 ,we will present the claims of each side1 therefore1 with the preliminary statement that 7for all except the severest conditions of accuracy7 either form1 if well made will answer every purpose and that therefore1 except in special circumstances1 these objections are more theoretical than real4 ,the advocates of metallic compensation claim that where there are great differences of temperature1 the compensated rod1 with its long bars will answer more quickly to temperature changes as follows3 ,the mercurial pendulum1 when in an unheated room and not subjected to sudden temperature changes1 gives very excellent results1 but should the opposite case occur there will then be observed an irregularity in the rate of the clock4 ,the causes which produce these effects are various4 ,as a principal reason for such a condition it may be stated that the compensating mercury occupies only about one-fifth the pendulum length1 and it inevitably follows that when the upper strata of the air is warmer than the lower1 in which the mercury is placed1 the steel pendulum rod will expand at a different ratio than the mercury1 as the latter is influenced by a different degree of temperature than the upper part of the pendulum rod4 ,the natural effect will be a lengthening of the pendulum rod1 notwithstanding the compensation1 and therefore1 a loss of time by the clock4 ,two thermometers1 agreeing perfectly1 were placed in the case of a clock1 one near the point of suspension1 and the other near the middle of the ball1 and repeated experiments1 showed a difference between these two thermometers of #g to #aj ,f41 the lower one indicating less than the higher one4 ,the thermometers were then hung in the room1 one at twenty-two inches above the floor1 and the other three feet higher1 when they showed a difference of #g between them4 ,the difference of #b4e more which was found inside the case proceeds from the heat striking the upper part of the case2 and the wood1 though a bad conductor1 gradually increases in temperature1 while1 on the contrary1 the cold rises from the floor and acts on the lower part of the case4 ,the same thermometers at the same height and distance in an unused room1 which was never warmed1 showed no difference between them2 and it would be the same1 doubtless1 in an observatory4 ,from the preceding it is very evident that the decrease of rate of the clock since ,december #ac proceeded from the rod of the pendulum experiencing #g to #aj4e ,f4 greater heat than the mercury in the bob1 thus showing the impossibility of making a mercurial pendulum perfectly compensating in an artificially heated room which varies greatly in temperature4 ,i should remark here that during the entire winter the temperature in the case is never more than #fh ,f41 and during the summer1 when the rate of the clock was regular1 the thermometer in the case has often indicated #gb to #gg ,f4 ,the gridiron pendulum in this case would seem preferable1 for if the temperature is higher at the top than at the lower part1 the nine compensating rods are equally affected by it4 ,but in its compensating action it is not nearly as regular1 and it is very difficult to regulate it1 for in any room 7artificially heated7 it is impossible to obtain a uniform temperature throughout its entire length1 and without that all proofs are necessarily inexact4 ,these facts can also be applied to pendulums situated in heated rooms4 ,in the case of a rapid change in temperature taking place in the observatory rooms1 under the domes of observatories1 especially during the winter months1 and which are of frequent occurrence1 a mercurial compensation pendulum1 as generally made1 is not apt to give a reliable rate4 ,let us accept the fact1 as an example1 of a considerable fall in the temperature of the surrounding air2 the thin pendulum rod will quickly accept the same temperature1 but with the great mass of mercury to be acted upon the responsive effects will only occur after a considerable lapse of time4 ,the result will be a shortening of the pendulum length and a gain in the rate until the mercury has had time to respond1 notwithstanding the compensation4 ,others who have expressed their views in writing seem to favor the idea that this inequality in the temperature of the atmosphere is unfavorable to the accurate action of the mercurial form of compensation2 and however plausible and reasonable this idea may seem at first notice1 it will not take a great amount of investigation to show that1 instead of being a disadvantage1 its existence is beneficial1 and an important element in the success of mercurial pendulums4 ,it appears that the majority of those who have proposed1 or have tried to improve ,graham's pendulum have overlooked the fact that different substances require different quantities of heat to raise them to the same temperature4 ,in order to warm a certain weight of water1 for instance1 to the same degree of heat as an equal weight of oil1 or an equal weight of mercury1 twice as much heat must be given to the water as to the oil1 and thirty times as much as to the mercury2 while in cooling down again to a given temperature1 the oil will cool twice as quick as the water1 and the mercury thirty times quicker than the water4 ,this phenomenon is accounted for by the difference in the amount of latent heat that exists in various substances4 ,on the authority of ,sir ,humphrey ,davy1 zinc is heated and cooled again ten and three-quarters times quicker than water1 brass ten and a half times quicker1 steel nine times1 glass eight and a half times1 and mercury is heated and cooled again thirty times quicker than water4 ,from the above it will be noticed that the difference in the time steel and mercury takes to rise and fall to a given temperature is as nine to thirty1 and also that the difference in the quantity of heat that it takes to raise steel and mercury to a given temperature is in the ratio of nine to thirty4 ,now1 without entering into minute details on the properties which different substances possess for absorbing or reflecting heat1 it is plain that mercury should move in a proportionally different atmosphere from steel in order to be expanded or contracted a given distance in the same length of time2 and to obtain this result the amount of difference in the temperature of the atmosphere at the opposite ends of the pendulum must vary a little more or less according to the nature of the material the mercury jars are constructed from4 ,differences in the temperature of the atmosphere of a room will generally vary according to its size1 the height of the ceiling1 and the ventilation of the apartment2 and if the difference must continue to exist1 it is of importance that the difference should be uniformly regular4 ,we must not lose sight of the fact1 however1 that clocks having these pendulums1 and placed in apartments every way favorable to an equal temperature1 and in some instances1 the clocks and their pendulums encased in double casing in order to more effectually obtain this result1 still the rates of the clock show the same eccentricities as those placed in less favorable position4 ,this clearly shows that many changes in the rates of fine clocks are due to other causes than a change in the temperature of the surrounding atmosphere4 ,still it must be admitted that any change in the condition of the atmosphere that surrounds a pendulum is a most formidable obstacle to be overcome by those who seek to improve compensated pendulums1 and it would be of service to them to know all that can possibly be known on the subject4 ,the differences spoken of above have resulted in some practical improvements1 which are3 #ast1 the division of the mercury into two1 three or four jars in order to expose as much surface as possible to the action of the air1 so that the expansion of the mercury should not lag behind that of the rod1 which it will do if too large amounts of it are kept in one jar4 #bnd1 the use of very thin steel jars made from tubing1 so that the transmission of heat from the air to the mercury may be hastened as much as possible4 #crd1 the increase in the number of jars makes a thinner bob than a single jar of the same total weight and hence gives an advantage in decreasing the resistant effect of air friction in dense air1 thereby decreasing somewhat the barometric error of the pendulum4 ,the original form of mercurial pendulums1 as made by ,graham1 and still used in tower and other clocks where extraordinary accuracy is not required1 was a single jar which formed the bob and had the pendulum rod extending into the mercury to assist in conducting heat to the variable element of the pendulum4 ,it is shown in section in ,fig4 #ac1 which is taken from a working drawing for a tower clock4 ,the pendulum1 ,fig4 #ac1 is suspended from the head or cock shown in the figure1 and supported by the clock frame itself1 instead of being hung on a wall1 since the intention is to set the clock in the center of the clockroom1 and also because the weight1 forty pounds1 is not too much for the clock frame to carry4 ,the head1 ,a1 forms a revolving thumb-nut1 which is divided into sixty parts around the circumference of its lower edge1 and the regulating screw1 ,b1 is threaded ten to the inch4 ,a very fine adjustment is thus obtained for regulating the time of the pendulum4 ,the lower end of the regulating screw1 ,b1 holds the end of the pendulum spring1 ,e1 which is riveted between two pieces of steel1 ,c1 and a pin1 ,c1 is put through them and the end of the regulating screw1 by which to suspend the pendulum4 ,the cheeks or chops are the pieces ,d1 the lower edges of which form the theoretical point of suspension of the pendulum4 ,these pieces must be perfectly square at their lower edges1 otherwise the center of gravity would describe a cylindrical curve4 ,the chops are clamped tightly in place by the setscrews1 ,d1 after the pendulum has been hung4 ,the lower end of the regulating screw is squared to fit the ways and slotted on one side1 sliding on a pin to prevent its turning and therefore twisting the suspension spring when it is raised or lowered4 ,the spring is three inches long between its points of suspension1 one and three-eighths inches wide1 and one-sixtieth of an inch thick4 ,its lower end is riveted between two small blocks of steel1 ,f1 and suspended from a pin1 ,f1 in the upper end of the cap1 ,g1 of the pendulum rod4 ,the tubular steel portion of the pendulum rod is seven-eighths of an inch in diameter and one-thirty-second of an inch thickness of the wall4 ,it is enclosed at each end by the solid ends1 ,g and ,l1 and is made as nearly air-tight as possible4 ,illustration3 ,fig4 #ac4 ,the compensation is by mercury inclosed in a cast iron bob4 ,the mercury1 the bob and the rod together weigh forty pounds4 ,the bob of the pendulum is a cast iron jar1 ,k1 three inches in diameter inside1 one-quarter inch thick at the sides1 and five-sixteenths thick at the bottom1 with the cap1 ,j1 screwed into its upper end4 ,the cap1 ,j1 forms also the socket for the lower end of the pendulum rod1 ,h4 ,the rod1 ,l1 one-quarter inch in diameter1 screws into the cap1 ,j1 and its large end at the same time forms a plug for the lower end of the pendulum tube1 ,h4 ,the pin1 ,j1 holds all these parts together4 ,the rod1 ,l1 extends nearly to the bottom of the jar1 and forms a medium for the transmission of the changes in temperature from the pendulum tube to the mercury4 ,the screw in the cap1 ,j1 is for filling or emptying the jar4 ,the jar is finished as smoothly as possible1 outside and inside1 and should be coated with at least three coats of shellac inside4 ,of course if one was building an astronomical clock1 it would be necessary to boil the mercury in the jar in order to drive off the layer of air between the mercury and the walls of the jar1 but with the smooth finish the shellac will give1 in addition to the good work of the machinist1 the amount of air held by the jar can be ignored4 ,the cast iron jar was decided upon because it was safer to handle1 can be attached more firmly to the rod with less multiplication of parts1 and also on account of the weight as compared with glass1 which is the only other thing that should be used1 the glass requiring a greater height of jar for equal weight4 ,in making cast iron jars1 they should always be carefully turned inside and out in order that the walls of the jar may be of equal thickness throughout2 then they will not throw the pendulum out of balance when they are screwed up or down on the pendulum rod in making the coarse regulation before timing by the upper screw4 ,the thread on the rod should have the cover of the jar at about the center of the thread when nearly to time and that portion which extends into the jar should be short enough to permit this4 ,ignoring the rod and its parts for the present1 and calling the jar one-third of the weight of the mercury1 we shall find that thirty pounds of mercury1 at 4#di pounds per cubic inch1 will fill a cylinder which is three inches inside diameter to a height of #h4haf inches1 after deducting for the mass of the rod ,l1 when the temperature of the mercury is #fj degrees ,f4 ,mercury expands one-tenth in bulk1 while cast iron expands 4#jjff in diameter3 so the sectional area increases as #a4jjff or #a4jacb to #a1 therefore the mercury will rise 4#a-4jacbdc1 or 4#jhfgeg2 then the mercury in our jar will rise 4#gfg of an inch in the ordinary changes of temperature1 making a total height of #i4eh inches to provide for2 so the jar was made ten inches long4 ,pendulums of this pattern as used in the high grade ,english clocks1 are substantially as follows3 ,rod of steel _/ inch diameter2 jar about #b4a inches diameter inside and #h inches deep inside4 ,the jar may be wrought or cast iron and about of an inch thick with the cover to screw on with fine thread1 making a tight joint4 ,the cover of the jar is to act as a nut to turn on the rod for regulation4 ,the thread cut on the rod should be thirty-six to the inch1 and fit into the jar cover easily1 so that it may turn without binding4 ,with a thirty-six thread one turn of the jar on the rod changes the rate thirty seconds per day and by laying off on the edge of the cover #cj divisions1 a scale is made by which movements for one second per day are obtained4 ,we will now describe 7,fig4 #ad7 the method of making a mercurial pendulum to replace an imitation gridiron pendulum for a ,swiss1 pin escapement regulator1 such as is commonly found in the jewelry stores of the ,united ,states1 that is1 a clock in which the pendulum is supported by the plates of the movement and swings between the front plate and the dial of the movement4 ,in thus changing our pendulum1 we shall desire to retain the upper portion of the old rod1 as the fittings are already in place and we shall save considerable time and labor by this course4 ,as the pendulum is suspended from the movement1 it must be lighter in weight than if it were independently supported by a cast iron bracket1 as shown in ,fig4 #f1 so we will make the weight about that of the one we have removed1 or about twelve pounds4 ,if it is desired to make the pendulum heavier1 four jars of the dimensions given would make it weigh about twenty pounds1 or four jars of one inch diameter would make a thinner bob and one weighing about fourteen pounds4 ,as the substitution of a different number or different sizes of jars merely involves changing the lengths of the upper and lower bars of the frame1 further drawings will be unnecessary1 the jeweler having sufficient mechanical capacity to be able to make them for himself4 ,i might add1 however1 that the late ,edward ,howard1 in building his astronomical clocks1 used four jars containing twenty-eight pounds of mercury for such movements1 and the perfection of his trains was such that a seven-ounce driving weight was sufficient to propel the thirty pound pendulum4 ,the two jars are filled with mercury to a height of #g inches1 are #a inches in diameter outside and #h inches in height outside4 ,the caps and foot pieces are screwed on and when the foot pieces are screwed on for the last time the screw threads should be covered with a thick shellac varnish which1 when dry1 makes the joint perfectly air-tight4 ,the jars are best made of the fine1 thin tubing1 used in bicycles1 which can be purchased from any factory1 of various sizes and thickness4 ,in the pendulum shown in the illustration1 the jar stock is close to #ad wire gauge1 or about #b mm4 in thickness4 ,in cutting the threads at the ends of the jars they should be about #cf threads to the inch1 the same number as the threads on the lower end of the rod used to carry the regulating nut4 ,a fine thread makes the best job and the tightest joints4 ,the caps to the jars are turned up from cold rolled shafting1 it being generally good stock and finishes well4 ,the threads need not be over _/ inch1 which is ample4 ,cut the square shoulder so the caps and foot pieces come full up and do not show any thread when screwed home4 ,these jars will hold ten pounds of mercury and this weight is about right for this particular style of pendulum4 ,the jars complete will weigh about seven ounces each4 ,illustration3 ,fig4 #ad4 ,the frame is also made of steel and square finished stock is used as far as possible and of the quality used in the caps4 ,the lower bar of the frame is six inches long and inch square at the center and tapered1 as shown in the illustration4 ,it is made light by being planed away on the under side1 an end view being shown at #c4 ,the top bar of the frame1 shown at #d1 is planed away also and is one-half inch square the whole length and is six inches long4 ,the two side rods are to bind the two bars together1 and with the four thumb nuts at the top and bottom make a strong light frame4 ,the pendulum described is nickel plated and polished1 except the jars1 which are left half dead2 that is1 they are frosted with a sand blast and scratch brushed a little4 ,the effect is good and makes a good contrast to the polished parts4 ,the side rods are five inches apart1 which leaves one-half inch at the ends outside4 ,the rod is _/ of an inch in diameter and #cc inches long from the bottom of the frame at a point where the regulating nut rests against it to the lower end of the piece of the usual gridiron pendulum shown in ,fig4 #ad at #aj4 ,this piece shown is the usual style and size of those in the majority of these clocks and is the standard adopted by the makers4 ,this piece is #aa inches long from the upper leaf of the suspension spring1 which is shown at #ab1 to the lower end marked #aj4 ,by cutting out the lower end of this piece1 as shown at #aj1 and squaring the upper end of the rod1 pinning it into the piece as shown1 the union can be made easily and any little adjustments for length can be made by drilling another set of holes in the rod and raising the pendulum by so doing to the correct point4 ,a rod whose total length is #cg inches will leave #b inches for the prolongation below the frame carrying the regulating nut1 #i1 and for the portion squared at the top1 and will then be so long that the rate of the clock will be slow and leave a surplus to be cut off either at the top or bottom1 as may seem best4 ,the screw at the lower end carrying the nut should have #cf threads to the inch and the nut graduated to #cj divisions1 each of which is equal in turning the nut to one minute in #bd hours1 fast or slow1 as the case may be4 ,the rod should pass through the frame bars snugly and not rattle or bind4 ,it also should have a slot cut so that a pin can be put through the upper bar of the frame to keep the frame from turning on the rod and yet allow it to move up and down about an inch4 ,the thread at the lower end of the rod should be cut about two inches in length and when cutting off the rod for a final length1 put the nut in the middle of the run of the thread and shorten the rod at the top4 ,this will be found the most satisfactory method1 for when all is adjusted the nut will stand in the middle of its scope and have an equal run for fast or slow adjustment4 ,with the rod of the full length as given1 this pendulum had to be cut at the top about one inch to bring to a minute or two in twenty-four hours1 and this left all other points below corrected4 ,the pin in the rod should be adjusted the last thing1 as this allows the rod to slide on the pin equal distances each way4 ,one inch in the raising or lowering of the frame on the rod will alter the rate for twenty-four hours about eighteen minutes4 ,many attempts have been made to combine the good qualities of the various forms of pendulums and thus produce an instrument which would do better work under the severe exactions of astronomical observatories and master clocks controlling large systems4 ,the reader should understand that1 just as in watch work1 the difficulties increase enormously the nearer we get towards absolute accuracy1 and while anybody can make a pendulum which will stay within a minute a month1 it takes a very good one to stay within five seconds per month1 under the conditions usually found in a store1 and such a performance makes it totally unfit for astronomical work1 where variations of not over five-thousandths of a second per day are demanded4 ,in order to secure such accuracy every possible aid is given to the pendulum4 ,barometric errors are avoided by enclosing it in an air-tight case1 provided with an air pump2 the temperature is carefully maintained as nearly constant as possible and its performance is carefully checked against the revolutions of the fixed stars1 while various astronomers check their observations against each other by correspondence1 so that each can get the rate of his clock by calculations of observations and the law of averages1 eliminating personal errors4 ,one of the successful attempts at such a combination of mercury and metallic pendulums is that of ,riefler1 as shown in ,fig4 #ae1 which illustrates a seconds pendulum one-thirtieth of the actual size4 ,it consists of a ,mannesmann steel tube 7rod71 bore #af mm41 thickness of metal #a mm41 filled with mercury to about two-thirds of its length1 the expansion of the mercury in the tube changing the center of weight an amount sufficient to compensate for the lengthening of the tube by heat1 or vice versa4 ,the pendulum1 has further1 a metal bob weighing several kilograms1 and shaped to cut the air4 ,below the bob are disc shaped weights1 attached by screw threads1 for correcting the compensation1 the number of which may be increased or diminished as appears necessary4 ,whereas in the ,graham pendulum regulation for temperature is effected by altering the height of the column of mercury1 in this pendulum it is effected by changing the position of the center of weight of the pendulum by moving the regulating weights referred to1 and thus the height of the column of mercury always remains the same1 except as it is influenced by the temperature4 ,illustration3 ,,column ,,of ,,mercury ,fig4 #ae4 ,a correction of the compensation should be effected1 however1 only in case the pendulum is to show sidereal time1 instead of mean solar time1 for which latter it is calculated4 ,in this case a weight of #aaj to #abj grams should be screwed on to correct the compensation4 ,in order to calculate the effect of the compensation1 it is necessary to know precisely the coefficients of the expansion by heat of the steel rod1 the mercury1 and the material of which the bob is made4 ,the last two of these coefficients of expansion are of subordinate importance1 the two adjusting screws for shifting the bob up and down being fixed in the middle of the latter4 ,a slight deviation is1 therefore1 of no consequence4 ,in the calculation for all these pendulums the co-efficient for the bob is1 therefore1 fixed at #j4jjjjah1 and for the mercury at #j4jjjahacf1 being the closest approximation hitherto found for chemically pure mercury1 such as that used in these pendulums4 ,the co-efficient of the expansion of the steel rod is1 however1 of greater importance4 ,it is therefore1 ascertained for every pendulum constructed in ,mr4 ,riefler's factory1 by the physikalisch-technische ,reichsanstalt at ,charlottenburg1 examinations showing1 in the case of a large number of similar steel rods1 that the co-efficient of expansion lies between #j4jjjjajcd and #j4jjjjaafb4 ,the precision with which the measurements are carried out is so great that the error in compensation resulting from a possible deviation from the true value of the co-efficient of expansion1 as ascertained by the ,reichsanstalt1 does not amount to over #j4jjag2 and1 as the precision with which the compensation for each pendulum may be calculated absolutely precludes any error of consequence1 ,mr4 ,riefler is in a position to guarantee that the probable error of compensation in these pendulums will not exceed #j4jje seconds per diem and #a variation in temperature4 ,a subsequent correction of the compensation is1 therefore1 superfluous1 whereas1 with all other pendulums it is necessary1 partly because the coefficients of expansion of the materials used are arbitrarily assumed2 and partly because none of the formul hitherto employed for calculating the compensation can yield an exact result1 for the reason that they neglect to notice certain important influences1 in particular that of the weight of the several parts of the pendulum4 ,such formul are based on the assumption that this problem can be solved by simple geometrical calculation1 whereas1 its exact solution can be arrived at only with the aid of physics4 ,this is hardly the proper place for details concerning the lengthy and rather complicated calculations required by the method employed4 ,it is intended to publish them later1 either in some mathematical journal or in a separate pamphlet4 ,here ,i will only say that the object of the whole calculation is to find the allowable or requisite weight of the bob1 i4 e41 the weight proportionate to the coefficients of expansion of the steel rod1 dimensions and weight of the rod and the column of mercury being given in each separate case4 ,to this end the relations of all the parts of the pendulum1 both in regard to statics and inertia1 have to be ascertained1 and for various temperatures4 ,a considerable number of these pendulums have already been constructed1 and are now running in astronomical observatories4 ,one of them is in the observatory of the ,university of ,chicago1 and others are in ,europe4 ,the precision of this compensation which was discovered by purely theoretical computations1 has been thoroughly established by the ascertained records of their running at different temperatures4 ,the adjustment of the pendulums1 which is1 of course1 almost wholly without influence on the compensation1 can be effected in three different ways2 7#a47 ,the rough adjustment1 by screwing the bob up or down4 7#b47 ,a finer adjustment1 by screwing the correction discs up or down4 7#c47 ,the finest adjustment1 by putting on additional weights4 ,these weights are to be placed on a cup attached to a special part of the rod of the pendulum4 ,their shape and size is such that they can be readily put on or taken off while the pendulum is swinging4 ,their weight bears a fixed proportion to the static momentum of the pendulum1 so that each additional weight imparts to the pendulum1 for twenty-four hours1 an acceleration expressed in even seconds and parts of seconds1 and marked on each weight4 ,each pendulum is accompanied with additional weights of ,german silver1 for a daily acceleration of #a second each1 and ditto of aluminum for an acceleration of #j4e and #j4a second respectively4 ,a metal clasp attached on the rear side of the clock case1 may be pushed up to hold the pendulum in such a way that it can receive no twisting motion during adjustment4 ,further1 a pointer is attached to the lower end of the pendulum1 for reading off the arc of oscillation4 ,the essential advantages of this pendulum over the mercurial compensation pendulums are the following3 7#a47 ,it follows the changes of temperature more rapidly1 because a small amount of mercury is divided over a greater length of pendulum1 whereas1 in the older ones the entire 7and decidedly larger7 mass of mercury is situated in a vessel at the lower end of the pendulum rod4 7#b47 ,for this reason differences in the temperature of the air at different levels have no such disturbing influence on this pendulum as on the others4 7#c47 ,this pendulum is not so strongly influenced as the others by changes in the atmospheric pressure1 because the principal mass of the pendulum has the shape of a lens1 and therefore cuts the air easily4 ,,chapter ,v4 ,,regulations1 ,,suspensions1 ,,crutches ,,and ,,minor ,,points4 ,,regulation4--,the reader will have noticed that in describing the various forms of seconds pendulums we have specified either eighteen or thirty-six threads to the inch2 this is because a revolution of the nut with such a thread gives us a definite proportion of the length of the rod1 so that it means an even number of seconds in twenty-four hours4 ,moving the bob up or down _/ inch makes the clock having a seconds pendulum gain or lose in twenty-four hours one minute1 hence the selecting definite numbers of threads has for its reason a philosophical standpoint1 and is not a matter of convenience and chance1 as seems to be the practice with many clockmakers4 ,with a screw of eighteen threads1 we shall get one minute change of the clock's rate in twenty-four hours for every turn of the nut1 and if the nut is divided into sixty parts at its edge1 each of these divisions will make a change of the clock's rate of one second in twenty-four hours4 ,thus by using a thread having a definite relation to the length of the rod regulating is made comparatively easy1 and a clock can be brought to time without delay4 ,suppose1 after comparing your clock for three or four days with some standard1 you find it gains twelve seconds per day1 then1 turning the nut down twelve divisions will bring the rate down to within one second a day in one operation1 if the screw is eighteen threads4 ,with the screw thirty-six threads the nut will require moving just the same number of divisions1 only the divisions are twice as long as those with the screw of eighteen threads4 ,the next thing is the size and weight of the nut4 ,if it is to be placed in the middle of the bob as in ,figs4 #aj1 #ab and #ae1 it should project slightly beyond the surface and its diameter will be governed by the thickness of the bob4 ,if it is an internal nut1 worked by means of a sleeve and disc1 as in ,fig4 #i1 the disc should be of sufficient diameter to make the divisions long enough to be easily read4 ,if the nut is of the class shown in ,fig4 #e1 #f1 #g1 a nut is most convenient1 #a inch in diameter1 and cut on its edge into thirty equal divisions1 each of which is equal to one second in change of rate in twenty-four hours1 if the screw has thirty-six threads to the inch4 ,this gives #c4adaf inches of circumference for the thirty divisions1 which makes them long enough to be subdivided if we choose1 each division being a little over one-tenth of an inch in length1 so that quarter-seconds may be measured or estimated4 ,with some pendulums1 ,fig4 #ac1 the bob rotates on the rod1 and is in the form of a cylinder1 say #h inches long by #b inches in diameter1 and the bob then acts on its rod as the nut does1 and moves up and down when turned1 and in this form of bob the divisions are cut on the outside edge of the cover of the bob1 and are so long that each one is subdivided into five or ten smaller divisions1 each altering the clock 4#b or 4#a second per day4 ,on the top of the bob turn two deep lines1 close to the edge1 about -inch apart1 and divide the whole diameter into thirty equal divisions1 and subdivide each of the thirty into five1 and this will give seconds and fifths of seconds for twenty-four hours4 ,each even seconds division should be marked heavier than the fraction1 and should be marked from one to thirty with figures4 ,just above the cover on the rod should slide a short tube1 friction-tight1 and to this a light index or hand should be fastened1 the point of which just reaches the seconds circle on the bob cover1 and thus indicates the division1 its number and fraction4 ,the tube slides on the rod because the exact place of the hand cannot be settled until it has been settled by experiment4 ,after this it can be fastened permanently1 if thought best1 though as described it will be all sufficient4 ,while the bob is being raised or lowered to bring the clock to its rate1 the bob might get too far away or too near to the index and necessitate its being shifted1 and if friction-tight this can be readily accomplished1 and the hand be brought to just coincide with the divisions and look well and be a means of accomplishing very accurate minute adjustments4 ,,suspensions4--,suspensions are of four kinds1 cord1 wire loop1 knife edges and springs4 ,cords are generally of loosely twisted silk and are seldom found except in the older clocks of ,french or ,swiss construction4 ,they have been entirely displaced in the later makes of ,european manufactures by a double wire loop1 in which the pendulum swings from a central eye in the loop1 while the loop rocks upon a round stud by means of an eye at each end of the loop4 ,the eyes should all be in planes parallel to the plane of oscillation of the pendulum1 otherwise the bob will take an elliptical path instead of oscillating in a plane4 ,they should also be large enough to roll without friction upon the stud and center of the loop1 as any slipping or sliding of either will cause them to soon wear out1 besides affecting the rate of the pendulum4 ,properly constructed loops will give practically no friction and make a very free suspension that will last as long as the clock is capable of keeping time1 although it seems to be a very weak and flimsy method of construction at first sight4 ,care should be taken in such cases to keep the bob from turning when regulating the clock1 or the effect upon the pendulum will be the same as if the eyes were not parallel4 ,knife edge suspensions are also rare now1 having been displaced by the spring1 as it was found the vibrations were too free and any change in power introduced a circular error 7,see ,fig4 #d7 by making the long swings in longer time4 ,they are still to be found1 however1 and in repairing clocks containing them the following points should be observed3 ,the upper surface of the stud on which the pendulum swings should carry the knife edge at its highest point1 exactly central with the line of centers of the stud1 so that when the pendulum hangs at rest the stud shall taper equally on both sides of the center1 thus giving equal freedom to both sides of the swing4 ,care should be taken that the stud is firmly fixed1 with the knife edge exactly at right angles to the movement1 and also to the back of the case4 ,the suspension stud and the block on the rod should be long enough to hold the pendulum firmly in line1 as the angle in the top of the rod must be the sole means of keeping the pendulum swinging in plane4 ,the student will also perceive the necessity of making the angle occupy the proper position on the rod1 especially if the latter be flat4 ,in repairing this suspension it is usual to make the plate1 fasten it in place and then drill and file out the hole1 as it is easier to get the angles exactly in this way than to complete the plate and then attempt to fasten it in the exact position in which it should be4 ,after fastening the plates in position on the rod1 two holes should be drilled1 a small one at the apex of the angle 7which must be exactly square and true with the rod71 and a larger one below it large enough to pass the files easily4 ,the larger hole can then be enlarged to the proper size1 filing the angle at the top in such a way that the small hole first drilled forms the groove at the apex of the angle in which the knife edge of the stud shall work when it is completed4 ,knife edge suspensions are unfitted for heavy pendulums1 as the weight causes the knife edge to work into the groove and cut it1 even if the latter be jeweled4 ,both the edge and groove should be hardened and polished4 ,,pendulum ,,suspension ,,springs4--,next in importance to the pendulum is its suspension spring4 ,this spring should be just stiff enough to make the pendulum swing in all its vibrations in the same time2 that is1 if the pendulum at one time swung at the bottom of the jar #a inch each side of the center1 and at another time it swung only #a inch each side1 that the two should be made in exactly one second4 ,the suspension springs are a point in the construction of a fine pendulum1 that there has been very much theorizing on1 but the experiments have never thus far exactly corroborated the theories and there are no definite rules to go by1 but every maker holds to that plan and construction that gives his particular works the best results4 ,a spring of sufficient strength to materially influence the swing of the pendulum is of course bad1 as it necessitates more power to give the pendulum its proper motion and hence there is unnecessary wear on the pallets and escape wheel teeth1 and too weak a spring is also bad1 as it would not correct any inequalities in the time of swing and would in time break from overloading1 as its granular structure would finally change1 and rupture of the spring would follow4 ,the office of a spring is to sustain the weight without detriment to strength and elasticity1 and if so proportioned to the weight as to be just right1 it will make the long and short swings of the pendulum of equal duration4 ,when a pendulum hung by a cord or knife edge instead of a spring is regulated to mean time and swings just two inches at the bottom1 any change in the power that swings the pendulum will increase its movement or decrease it1 and in either case the rate will change1 but with a proper spring the rate will be constant under like conditions4 ,the action of the spring is this3 ,in the long swings the spring1 as it bends1 lifts the pendulum bob up a little more than the arc of the normal circle in which it swings1 and consequently when the bob descends1 in going to the center of its swing1 it falls a little quicker than it does when held by a cord1 and this extra quick drop can be made to neutralize the extra time taken by the bob in making extra long swings4 ,see ,fig4 #d4 ,this action is the isochronal action of the spring1 the same that is attained in isochronal hair springs in watches4 ,as with the hairspring1 it is quite necessary that the pendulum spring be accurately adjusted to isochronism and my advice to every jeweler is to thoroughly test his regulator1 which can easily be done by changing the weight or motive power4 ,if the test should prove the lack of isochronism he can adjust it by following these simple rules4 ,fig4 #af is the pendulum spring or leaf4 ,if the short arcs should prove the slowest1 make the spring a trifle thinner at ,b2 if fastest1 reduce the thickness of the spring at ,a4 ,continue the test until the long and short arcs are equal4 ,in doing this care must be taken to thin each spring equally1 if it is a double spring1 and each edge equally1 if a single spring1 as if one side be left thicker than the other the pendulum will wabble4 ,illustration3 ,fig4 #af4 ,the cause of a pendulum wobbling is that there must be something wrong with the suspension spring1 or the bridge that holds the spring4 ,if the suspension spring is bent or kinked1 the pendulum will wabble2 or if the spring should be of an unequal thickness it will have the same effect on the pendulum2 but the main cause of the pendulum wobbling in ,american clocks is that the slot in the bridge that holds the spring1 or the slot in the slide that works up and down on the spring 7which is used to regulate the clock7 is not parallel4 ,when this slot is not parallel it pinches the spring1 front or back1 and allows it to vibrate more where it is the freest1 causing the pendulum to wabble4 ,we have found that by making these slots parallel the wobbling of the pendulum has ceased in most all cases4 ,if the pallet staff is not at right angles to the crutch1 wobbling may be caused by the oblique action of the crutch4 ,this often happens when the movement is not set square in the case4 ,it occasionally happens in mantel clocks that the pendulum when brought to time is just too long for the case when too thick a spring is used4 ,in such a case thinning the spring will require the bob to be raised a little and also give a better motion4 ,if compelled to make a spring use a piece of mainspring about 4#jjg thick and wide for small pendulums and the same spring doubled for heavier pendulums1 making the acting part of the spring about #a4e inches long4 ,the suspension spring for a rather heavy pendulum is better divided1 that is1 two springs1 held by two sets of clamps1 and jointly acting as one spring4 ,the length will be the same as to the acting part1 and that part held at each end by the clamps may be inch long2 total length1 #a4e inches with inch at each end held in the clamps4 ,these clamps are best soldered on to the spring with very low flowing solder so as not to draw the temper of the spring1 and then two rivets put through the whole1 near the lower edge of the clamps4 ,the object of securing the clamps so firmly is so that the spring may not bend beyond the edge of the clamps1 as if this should take place the clock will be thrown off of its rate4 ,after a time the rate would settle and become steady1 but it only causes an extra period of regulating that does not occur when the clamps hold the spring immovable at this point4 ,about in the center of each of the clamps1 when soldered and riveted1 is to be a hole bored for a pin1 which pins the clamp into the bracket and holds the weight of the pendulum4 ,the width of this compound spring for a seconds' pendulum of average weight may be 4#fj inch1 from outside to outside1 each spring 4#ae inch wide4 ,this will separate the springs 4#cj inch in the center4 ,with this form of spring1 the lower end of each spring being held in a pair of clamps1 the clamps will have to be let into the top of the rod1 and held in by a stout pin1 or the pendulum finished with a hook which will fit the clamp4 ,in letting the clamp into the rod1 the clamp should just go into the mortise and be without side shake1 but tilt each way from the center a little on the pin1 so that when the pendulum is hung it may hang perpendicular1 directly in the center of both springs4 ,also1 the top pair of clamps should fit into a bracket without shake1 and tilt a little on a pin1 the same as the lower clamps4 ,these two points1 each moving a little1 helps to take any side twist away1 and allows the whole mechanism to swing in line with the center of gravity of the mass from end to end4 ,with the parts well made1 as described1 the bob will swing in a straight line from side to side1 and its path will be without any other motion except the one of slight curvature1 due to being suspended by a fixed point at the upper clamp4 ,,pendulum ,,supports4--,stability in the movement and in the suspension of the pendulum is very necessary in all forms of clocks for accurate timekeeping4 ,the pendulum should be hung on a bracket attached to the back of the case 7see ,fig4 #f71 and not be subject to disturbance when the movement is cleaned4 ,also the movement should rest on two brackets attached to the bracket holding the pendulum and the whole be very firmly secured to the back board of the case4 ,screws should go through the foot pieces of the brackets and into a stone or brick wall and be very firmly held against the wall just back of the brackets4 ,any instability in this part of a clock is very productive of poor rates4 ,the bracket1 to be in its best form1 is made of cast iron1 with a large foot carrying all three separate brackets1 well screwed to a strong back board and the whole secured to the masonry by bolts4 ,too much firmness cannot be attained1 as a lack of it is a very great fault1 and many a good clock is a very poor timekeeper1 due to a lack of firmness in its supports and fastenings4 ,the late ,edward ,howard used to make his astronomical clocks with a heavy cast iron back1 to which the rest of the case was screwed1 so that the pendulum should not swing the case4 ,any external influence that vibrates a wall or foundation on which a clock is placed1 is a disturbing influence1 but an instability in a clock's attachment to such supports is a greater one4 ,many pendulums swing the case in which they hang 7from unstable setting up7 and never get down to or maintain a satisfactory rate from that cause4 ,this is also aggravated by the habit of placing grandfather clocks on stair landings or other places subject to jarring4 ,the writer knows of several clocks which1 after being cleaned1 kept stopping until raised off the floor and bolted to the wall1 when they at once took an excellent rate4 ,the appearance of resting on the floor may be preserved1 if desirable1 by raising the clock only half an inch or so1 just enough to free it from the floor4 ,,crutches4--,the impulse is transmitted to the pendulum from the pallet staff by means of a wire1 or slender rod1 fastened at its upper end to the pallet staff and having its lower end terminating in a fork 7crutch71 loop1 or bent at right angles so as to work freely in a slot in the rod4 ,it is also called the verge wire1 owing to the fact that older writers and many of the older workmen called the pallet fork the verge1 thus continuing the older nomenclature1 although of necessity the verge disappeared when the crown wheel was discarded4 ,in order to avoid friction at this very important point1 the centers of both axes of oscillation1 that of the pallet arbor and that of the pendulum spring1 where it bends1 should be in a straight horizontal line4 ,if1 for instance1 the center of suspension of the pendulum be higher1 then the fork and the pendulum describe two different arcs of circles2 that of the pendulum will be greater than that of the fork at their meeting point4 ,if1 however1 the center of suspension of the pendulum be lower than that of the fork1 they will also describe two different arcs1 and that of the pendulum will be smaller than that of the fork at their point of meeting4 ,this1 as can be readily understood1 will cause friction in the fork1 the pendulum going up and down in it4 ,this is prevented when1 as stated before1 the center of suspension of the pendulum is in the prolonged straight imaginary line going through the center of the pivots of the fork1 which will cause the arcs described by the fork and the pendulum to be the same4 ,it will be well understood from the foregoing that the pendulum should neither be suspended higher nor lower1 nor to the left1 nor to the right of the fork4 ,if the centers of motion do not coincide1 as is often the case with cheap clocks with recoil escapements1 any roughness of the pendulum rod where it slides on the crutch will stop the clock1 and repairers should always see to it that this point is made as smooth as possible and be very slightly oiled when setting up4 ,if putting in a new verge wire1 the workman can always tell where to bend it to form the loop by noticing where the rod is worn and forming the loop so that it will reach the center of that old crutch or loop mark on the pendulum rod4 ,if the verge wire is too long1 it will give too great an arc to the pendulum if the latter is hung below the pallet arbor1 as is generally the case with recoil escapements of the cheap clocks1 and if it is too short there will not be sufficient power applied to the pendulum when the clock gets dirty and the oil dries1 in which case the clock will stop before the spring runs down4 ,an important thing to look after when repairing is in the verge wire and loop 7the slot the pendulum rod goes through74 ,after the clock is set up and oiled1 put it on a level shelf2 have a special adjusted shelf for this level adjusting1 one that is absolutely correct4 ,have the dial off4 ,if the beat is off on one side1 so that it bangs up heavily on one side of the escape wheel1 bend the verge wire the same way4 ,that will reverse the action and put it in beat4 ,so far so good--but don't stop now4 ,just notice whether if that shelf were tipped forward or back1 as perhaps your customer's may1 that the pendulum should still hang plumb and free4 ,now if the top of your clock tips forward1 the pendulum ball inclines to hang out toward the front4 ,we will suppose you put two small wedges under the back of the case4 ,now notice in its hanging out whether the pendulum rod pinches or bears in the throat of the verge2 or if it tips back1 see if the rod hits the other end of the slot4 ,this verge slot should be long enough1 with the rod hanging in the middle when adjusted to beat on a level1 to admit of the clock pitching forward or back a little without creating a friction on the ends of the slot4 ,this little loop should be open just enough to be nice and free2 if open too much1 you will notice the pallet fork will make a little jump when carrying the ball over by hand4 ,this is lost motion4 ,if this little bend of wire is not parallel it may be opened enough inside1 but if pitched forward a little it will bind in the narrowest part of the ,v and then the clock will stop4 ,the clock beat and the tipping out or in of the clock case1 causing a binding or bearing of the pendulum rod in this verge throat1 does more towards stopping clocks just repaired than all other causes4 ,,putting ,,in ,,beat4--,to put a clock in beat1 hang the clock in such a position that when the pendulum is at rest one tooth of the escape wheel will rest on the center of a pallet stone4 ,screwed on the case of the clock at the bottom of the pendulum there is1 or should be1 an index marked with degrees4 ,now1 while the escape wheel tooth is resting on the pallet1 as explained above1 the index of the pendulum should point to zero on the index4 ,move the pendulum until the tooth just escapes and note how many degrees beyond zero the pendulum point is4 ,say it escapes #b to the left2 now move the pendulum until the next tooth escapes--it should escape #b to the right4 ,but let us suppose it does not escape until the index of the pendulum registers #e to the right of zero4 ,in this case the rod attached to the pallets must be bent until the escape wheel teeth escape when the pendulum is moved an even number of degrees to the right and left of zero1 when the clock will be in beat4 ,,close ,,rating ,,with ,,shot4--,very close rating of a seconds' pendulum1 accompanied by records in the book1 may be got with the nut alone1 but there is the inconvenience of stopping the clock to make an alteration4 ,this may be avoided by having a small cup the size of a thimble or small pill box on the pendulum top4 ,this can be lifted off and put back without disturbing the motion of the pendulum4 ,in using it a number of small shot1 selected of equal size1 are put in1 say #fj1 and the clock brought as nearly as possible to time by the nut4 ,after a few days the cup may be emptied and put back1 when on further trial the value of the #fj shot in seconds a day will be found4 ,this value divided by #fj will give the value of a single shot1 by knowing which very small alterations of rate may be made with a definite approach towards accuracy1 and in much less time than by putting in or taking out one or more shot at random4 ,,chapter ,,vi4 ,,torsion ,,pendulums ,,for ,,four-,,hundred ,,day ,,clocks4 ,as this pendulum is only found in the #djj-;day1 or annual wind1 or anniversary clocks 7they are known by all of these names71 it is best to describe the pendulum and movement together1 as its relations to the work to be done may be more easily perceived4 ,rotating pendulums of this kind--that is1 in which the bob rotates by the twisting of the suspension rod or spring--will not bear comparison with vibrating pendulums for accurate timekeeping4 ,they are only used when a long period between windings is required4 ,small clocks to go for twelve months with one winding have the torsion pendulum ribbons of flat steel about six inches long1 making #ae beats per minute4 ,the time occupied in the beat of such a pendulum depends on the power of the suspending ribbon to resist twisting1 and the weight and distance from the center of motion of the bob4 ,in fact1 the action of the bob and suspending ribbon is very analogous to that of a balance and balance spring4 ,illustration3 ,fig4 #ag4 ,in order to get good time from a clock of this character1 it should be made with a dead-beat escapement4 ,with such an escapement there is no motion of the escape wheel1 after the tooth drops on the locking face of the pallet2 the escape wheel is dead and does not move again until it starts to give the pallet impulse4 ,this style of an escapement allows the pendulum as much freedom to vibrate as possible1 as the fork in one form of this escapement may leave the pallet pin as soon as the latter strikes the guard pins1 as in the ordinary lever escapement of a watch1 and it will remain in that position until the return of the fork unlocks the escapement to receive another impulse4 ,b1 ,fig4 #ag1 represents the escape wheel2 ,c1 the pallet2 ,e1 pallet staff2 ,d1 the pallet pin rivetted on to the pallet staff ,e1 which works in the slot or fork ,h2 this fork is screwed fast to the spring4 ,the spring ,g is made of a piece of flat steel wire and looks like a clock hairspring straightened out4 ,g is fast to the collar ,i and rests on a seat screwed to the plate of the clock1 as shown at ,p2 the spring is also fastened to the pendulum ball ,o with screws2 the ball makes about one and one-half revolutions each beat1 which causes the spring to twist4 ,it twists more at the point ,s than it does at ,l2 as it twists at ,l it carries the fork with it1 so that the latter vibrates from one side to the other1 similar to a fork in a watch4 ,this fork ,h carries the pin ,d1 which is fast to the pallet staff ,e1 far enough to allow the teeth to escape4 ,illustration3 ,fig4 #ah4 ,in the most common form of this escapement1 see ,fig4 #ah1 the fork does not allow the pin ,d to leave the slot ,h1 and the beat pins are absent1 the pendulum not being as highly detached as in the form previously mentioned4 ,in this case great care must be taken to have the edges of the slot1 which slide on the pallet pin1 smooth1 parallel and properly beveled1 so as not to bind on the pin4 ,the pendulum ball makes from eight to sixteen vibrations a minute4 ,of course the number depends upon the train of the clock4 ,in suspending the pendulum it is necessary to verify the drop of the teeth of the escape wheel as follows3 ,the pendulum is suspended and the locking position of the pallets marked1 taking as a guiding point the long1 regulating screw1 which1 fixed transversely in the support1 serves for adjusting the small suspension block4 ,an impulse of about a third of a turn is given to the pendulum while observing the escapement4 ,if the oscillations of the pendulum1 measured on the two sides1 taking the locking point as the base1 are symmetrical1 the drop is also equal1 and the rate of the clock regular and exact2 but if the teeth of the escape wheel are unlocked sooner on one side than on the other1 so that the pendulum in its swing passes beyond the symmetrical point on one of the pallets and does not reach it on the other1 it is necessary to correct the unequal drop4 ,illustration3 ,fig4 #ai4 ,the suspension block ,b1 ,fig4 #ah1 between the jaws of which the steel ribbon is pressed by two screws1 has a lower cylindrical portion1 which is fitted in a hole made in the seat1 and is kept immovable by the screw ,a4 ,if the vibration of the pendulum passes beyond the proper point on the left side1 it is necessary to loosen ,a and turn the suspension block slightly to the right4 ,if the deviation is produced in the opposite direction1 it is necessary to turn it to the left4 ,these corrections should be repeated until the drop of the escape wheel teeth on the pallets is exactly equal on the two sides4 ,as the drop is often disturbed by the fact that the long thin steel ribbon has been twisted in cleaning1 taking apart or handling by unskilled persons before coming to the watchmaker1 it is desirable to test the escapement again1 when the clock is put into position on the premises of the buyer4 ,illustration3 ,fig4 #bj4 ,the timing adjustment of the pendulum is effected with the aid of regulating weights1 placed on the ball4 ,by moving these away from the center by means of a right and left hand screw on the center of the disk 7see ,fig4 #ai71 the centrifugal force is augmented1 the oscillations of the pendulum slackened1 and the clock goes slower4 ,the contrary effect is produced if the weights are brought nearer the center4 ,in one form of ball the shifting of the regulating weights is accomplished by a compensating spring of steel and brass like the rim of a watch balance1 ,fig4 #bj4 ,if necessary to replace the pendulum spring1 the adjustment is commenced by shortening or lengthening the steel ribbon to a certain extent4 ,for this purpose the end of the spring is allowed to project above the suspension block as a reserve until adjustment has been completed1 when it may be cut off4 ,if the space between the ball and the bottom of the case1 or the bottom of the movement plates1 does not allow of attaining this end1 it is necessary to increase or decrease the weight of the disk1 adding one or several plates of metal in a depression made in the under side of the ball1 and removing the plates screwed to it1 which are too light4 ,there are some peculiarities of the trains of these clocks4 ,the cannon pinion is provided with a re-enforcing spring1 serving as guide to the dial work1 on which it exercises a sufficient pressure to assure precise working4 ,the pressure of this spring is important1 because if the dial work presses too hard on the pinion of the minute wheel1 the latter engaging directly with the escape wheel1 would transmit to the latter all the force employed in setting the hands4 ,the teeth of the escape wheel would incur damage and the consequent irregularity or even stopping of the clock would naturally follow4 ,in order that it may run for so long a time1 the motive force is transmitted through the train by the intervention of three supplementary wheels between the minute wheel and the barrel1 in order to avoid the employment of too large a barrel2 the third wheel is omitted2 the motion work is geared immediately with the arbor of the escape wheel4 ,it is evident that the system of the three intermediate wheels1 of which we have spoken1 requires for the motive force a barrel spring much stronger than that of ordinary clocks4 ,the points which we have noticed are of the most importance with reference to the repair and keeping in order of an annual clock4 ,it very often happens that when the repairer does not understand these clocks1 irregularities are sought for where they do not exist4 ,the pivot holes are bushed and the depthings altered1 when a more intelligent examination would show that the stopping1 or the irregular rate of the clock1 proceeds only from the condition of the escapement4 ,unless1 however1 they are perfectly adjusted1 a variation of five minutes a week is a close rate for them1 and most of those in use will vary still more4 ,annual clocks are enjoying an increased favor with the public2 their good qualities allow confidence1 the rate being quite regular when in proper order4 ,they are suitable for offices2 their silent running recommends them for the sick chamber1 and the subdued elegance of their decoration causes the best of them to be valued ornaments in the home4 ,,chapter ,,vii4 ,,peculiarities ,,of ,,angular ,,measurement--,,how ,,to ,,read ,,drawings4 ,we now come to a point at which1 if we are to keep our pendulum vibrating1 we must apply power to it1 evenly1 accurately and in small doses4 ,in order to do this conveniently we must store up energy by raising a weight or winding a spring and allow the weight to fall or the spring to unwind very slowly1 say in thirty hours or in eight days4 ,this brings about the necessity of changing rotary motion to reciprocating motion1 and the several devices for doing this are called 8escapements0 in horology1 each being further designated by the names of their inventors1 or by some peculiarity of the devices themselves2 thus1 the ,graham is also called the dead beat escapement2 ,le ,paute's is the pin wheel2 ,dennison's in its various forms is called the gravity2 ,hooke's is known as the recoil2 ,brocot's as the visible escapement1 etc4 ,,the ,,mechanical ,,elements4--,we shall understand this subject more clearly1 perhaps1 if we first separate these mechanical devices into their component parts and consider them1 not as parts of clocks1 but as various forms of levers1 which they really are4 ,this is perhaps the best place to consider the levers we are using to transmit the energy to the pendulum1 as at this point we shall find a greater variety of forms of the lever than in any other place in the clock1 and we shall have less difficulty in understanding the methods of calculating for time and power by a thorough preliminary understanding of leverage and the peculiarities of angular or circular motion4 ,if we take a bar1 ,a1 ,fig4 #ba1 and place under it a fulcrum1 ,b1 then by applying at ,c a given force1 we shall be able to lift at ,d a weight whose amount will be governed by the relative distances of ,c and ,d from the fulcrum ,b4 ,if the distance ,,cb is four times that of ,,bd1 then a force of #aj pounds at ,c will lift #dj pounds at ,d1 for one-fourth of the distance through which ,c moves1 minus the power lost by friction4 ,the reverse of this is also true2 that is1 it will take #dj pounds at ,d to exert a force of #aj pounds at ,c and the #aj pounds would be lifted four times as far as the #dj pound weight was depressed4 ,illustration3 ,fig4 #ba4 ,illustration3 ,fig4 #bb4 ,if instead of a weight we substitute other levers1 ,fig4 #bb1 the result would be the same1 except that we should move the other levers until the ends which were in contact slipped apart4 ,illustration3 ,fig4 #bc4 ,if we divide our lever and attach the long end to one portion of an axle1 as at ,a1 ,fig4 #bc1 and the short end to another part of it at ,b1 the result will be the same as long as the proportions of the lever are not changed4 ,it will still transmit power or impart motion according to the relative lengths of the two parts of the lever4 ,the capacity of our levers1 ,fig4 #bb1 will be limited by that point at which the ends of the levers will separate1 because they are held at the points of the fulcrums and constrained to move in circles by the fulcrums4 ,if we put more levers on the same axles1 so spaced that another set will come into action as the first pair are disengaged1 we can continue our transmission of power1 ,fig4 #bd2 and if we follow this with still others until we can add no more for want of room we shall have wheels and pinions1 the collection of short levers forming the pinion and the group of long levers forming the wheel1 ,fig4 #be4 ,thus every wheel and pinion mounted together on an arbor are simply a collection of levers1 each wheel tooth and its corresponding pinion leaf forming one lever4 ,this explains why the force decreases and the motion increases in proportion to the relative lengths of the radii of the wheels and pinions1 so that eight or ten turns of the barrel of a clock will run the escape wheel all day4 ,illustration3 ,fig4 #bd4 ,we now come to the verge or anchor1 and here we have the same sort of lever in a different form2 the verge wire1 which presses on the pendulum rod and keeps it going is the long arm of our lever1 but instead of many there is only one4 ,the short arm of our lever is the pallet1 and there are two of these4 ,therefore we have a form of lever in which there is one long arm and two short ones2 but as the two are never acting at the same time they do not interfere with each other4 ,illustration3 ,fig4 #be4 ,these systems of levers have another advantage1 which is that one arm need not be on the opposite side of the fulcrum from the other4 ,it may be on the same side as in the verge or at any other convenient point4 ,this enables us to save space in arranging our trains1 as such a collection of wheels and pinions is called1 by placing them in any position which1 on account of other facts1 may seem desirable4 ,,peculiarities ,,of ,,angular ,,motion4--,now our collections of levers must move in certain directions in order to be serviceable and in order to describe these things properly1 we must have names for these movements so that we can convey our thoughts to each other4 ,let us see how they move4 ,they will not move vertically 7up or down7 or horizontally 7sidewise71 because we have taken great pains to prevent them from doing so by confining the central bars of our levers in a fixed position by making pivots on their ends and fitting them carefully into pivot holes in the plates1 so that they can move only in one plane1 and that movement must be in a circular direction in that predetermined plane4 ,consequently we must designate any movement in terms of the portions of a circle1 because that is the only way they can move4 ,these portions of a circle are called angles1 which is a general term meaning always a portion of a circle1 measured from its center2 this will perhaps be plainer if we consider that whenever we want to be specific in mentioning any particular size of angle we must speak of it in degrees1 minutes and seconds1 which are the names of the standard parts into which a circle is divided4 ,now in every circle1 large or small1 there are #cfj degrees1 because a degree is _/th part of a circle1 and this measurement is always from its center4 ,consequently a degree1 or any angle composed of a number of degrees1 is always the same1 because1 being measured from its center1 such measurements of any two circles will coincide as far as they go4 ,if we draw two circles having their centers over each other at ,a1 ,fig4 #bf1 and take a tenth part of each1 we shall have #cfj #aj #cf1 which we shall mark out by drawing radial lines to the circumference of each circle1 and we shall find this to be true2 the radii of the smaller circle ,,ab and ,,ac will coincide with the radii ,,ad and ,,ae as far as they go4 ,this is because each is the tenth part of its circle1 measured from its center4 ,now that portion of the circumference of the circle ,,bc will be smaller than the same portion ,,de of the larger circle1 but each will be a tenth part of its own circle1 although they are not the same size when measured by a rule on the circumference4 ,this is a point which has bothered so many people when taking up the study of angular measurement that we have tried to make it absurdly clear4 ,an angle never means so many feet1 inches or millimeters2 it always means a portion of a circle1 measured from the center4 ,illustration3 ,fig4 #bf4 ,there is one feature about these angular 7or circular7 measurements that is of great convenience1 which is that as no definite size is mentioned1 but only proportionate sizes1 the description of the machine described need not be changed for any size desired1 as it will fit all sizes4 ,it thus becomes a flexible term1 like the fraction 8one-half10 changing its size to suit the occasion4 ,thus1 one-half of #cjj1jjj bushels of wheat is #aej1jjj bushels2 one-half of #aj bushels is #e bushels2 one-half of one bushel is two pecks2 yet each is one-half4 ,it is so with our angles4 ,there are some other terms which we shall do well to investigate before we leave the subject of angular measurements1 which are the relations between the straight and curved lines we shall need to study in our drawings of the various escapements4 ,a radius 7plural radii7 is a straight line drawn from the center of a circle to its circumference4 ,a tangent is a straight line drawn outside the circumference1 touching 7but not cutting7 it at right angles 7#ij degrees7 to a radius drawn to the point of tangency 7point where it touches the circumference74 ,a general misunderstanding of this term 7tangent7 has done much to hinder a proper comprehension of the writers who have attempted to make clear the mysteries of the escapements4 ,its importance will be seen when we recollect that about the first thing we do in laying out an escapement is to draw tangents to the pitch circle of the escape wheel and plant our pallet center where these tangents intersect on the line of centers4 ,they should always be drawn at right angles to the radii which mark the angles we choose for the working portion of our escape wheel4 ,if properly drawn we shall find that the pallet arbor will then locate itself at the correct distance from the escape wheel center for any desired angle of escapement4 ,we shall also discover that it will take a different center distance for every different angle and yet each different position will be the correct one for its angle1 ,fig4 #bg4 ,because an angle is always the same1 no matter how far from the center the radii defining it are carried1 we are able to work conveniently with large drawing instruments on small drawings4 ,thus we can use an eight or ten inch protractor in laying off our angles1 so as to get the degrees large enough to measure accurately1 mark the degrees with dots on our paper and then draw our lines with a straight edge from the center towards the dots1 as far as we wish to go4 ,thus we can lay off the angles on a one-inch escape wheel with a ten inch protractor more easily and correctly than if we were using a smaller instrument4 ,illustration3 ,fig4 #bg4 ,another thing which will help us in understanding these drawings is that the effective length of a lever is its distance from the center to the working point1 measured in a straight line4 ,thus in a pallet of a clock the distance of the pallets from the center of the pallet arbor is the effective length of that arm of the lever1 no matter how it may be curved for ornament or for other reasons4 ,the lines and circles drawn to enable us to take the necessary measurements of angles and center distances are called 8construction lines0 and are generally dotted on the paper to enable us to distinguish them as lines for measurement only1 while the lines which are intended to define the actual shapes of the pieces thus drawn are solid lines4 ,by observing this distinction we are enabled to show the actual shapes of the objects and all their angular measurements clearly on the one drawing4 ,with these explanations the student should be able to read clearly and correctly the many drawings which follow1 and we will now turn our attention to the escapements4 ,in doing this we shall meet with a constant use of certain terms which have a peculiar and special meaning when applied to escapements4 ,,the ,,lift is the amount of angular motion imparted to the verge or anchor by the teeth of the escape wheel pressing against the pallets and pushing first one and then the other out of the way1 so that the escape wheel teeth may pass4 ,according as the angular motion is more or less the 8lift0 is said to be greater or less2 as this motion is circular1 it must be expressed in degrees4 ,the lifting planes are those surfaces which produce this motion2 in clocks with pendulums the lifting planes are generally on the pallets1 being those hard and smoothly polished surfaces over which the points of the escape wheel teeth slide in escaping4 ,in lever escapements the lifting planes are frequently on the escape wheel1 the pallets being merely round pins4 ,such an escape wheel is said to have club teeth1 as distinguished from the pointed teeth used when the lifting planes are on the pallets4 ,in the cylinder escapement the lifting planes are on the escape wheel2 they are curved instead of being straight2 and there is but one pallet1 which is on the lip of the cylinder4 ,in the forms of lever escapement used in watches and some clocks the lift is divided1 part of the lifting planes being also on the pallets2 in this case both sets of planes are shorter than if they were entirely on one or the other1 but they must be long enough so that combined they will produce the requisite amount of angular motion of the pallets1 so as to give the requisite impulse to the pendulum or balance4 ,,the ,,drop is the amount of circular motion1 measured in degrees1 which the escape wheel has from the instant the tooth escapes from one pallet to that point at which it is stopped by the other pallet catching another tooth4 ,during this period the train is running down without imparting any power to the pendulum or balance1 hence the drop is entirely lost motion4 ,we must have it1 however1 as it requires some time for the other pallet to move far enough within the pitch circle of the escape wheel to safely catch and stop the next tooth under all circumstances4 ,it is the freedom and safety of the working plan of our escapement1 but it is advisable to keep the drop as small as is possible with safe locking4 ,,the ,,lock is also angular motion and is measured in degrees from the center of the pallet arbor4 ,it is the distance which the pallet has moved inside of the pitch circle of the escape wheel before being struck by the escape wheel tooth4 ,it is measured from the edge of the lifting plane to the point of the tooth where it rests on the locking face of the pallet4 ,a safe lock is necessary in order to prevent the points of the escape wheel teeth butting against the lifting planes1 stopping the clock and injuring the teeth4 ,we want to point out that from the instant of escaping to the instant of locking we have the two parts of our escapement propelled by different and entirely separate forces and moving at different speeds4 ,the pallets1 after having given impulse to the pendulum1 are controlled by the pendulum and moved by it2 in the case of a heavy pendulum ball at the end of a #dj-;inch lever1 this control is very steady1 powerful and quite slow4 ,the escape wheel1 the lightest and fastest in the train1 is driven by the weight or spring and moves independently of the pallets during the drop1 so that safe locking is important4 ,it should never be too deep1 as it would increase the swing of the pendulum too much2 this is especially true with short and light pendulums and strong mainsprings4 ,,the ,,run4--,after locking the pallet continues to move inward towards the escape wheel center as the pendulum continues its course1 and the amount of this motion1 measured in degrees from the center of the pallet arbor1 is called the run4 ,when the escapement is properly adjusted the lifting planes are of the same length on both pallets1 when they are measured in degrees of motion given to the pallet arbor4 ,they may or may not be equal in length when measured by a rule on the faces of the pallets4 ,there should also be an equal and safe lock on each pallet1 as measured in degrees of movement of the pallet arbor4 ,the run should also be equal4 ,the reason why one lifting plane may be longer than the other and still give the same amount of lift is that some escapements are constructed with unequal lockings1 so that one radius is longer than the other1 and this1 as we explained at length in treating of angles1 ,fig4 #bf1 would make a difference in the length of arc traversed by the longer arm for the same angle of motion4 ,,chapter ,,viii4 ,,the ,,graham ,,or ,,dead ,,beat ,,escapement4 ,this escapement is so-called because the escape wheel remains 8dead0 7motionless7 during the periods between the impulses given to the pendulum4 ,it is the original or predecessor of the well known detached lever escapement so common in watches1 and it is surprising how many watchmakers who are fairly well posted on the latter form exhibit a surprising ignorance of this escapement as used in clocks4 ,it has like the latter a 8lock10 8lift0 and 8run02 the only difference being that it has no 8draw10 the control by the verge wire rendering the draw unnecessary4 ,it may be made to embrace any number of teeth of the escape wheel1 but1 owing to the peculiarities of angular motion referred to in the last chapter1 see ,fig4 #bf1 ,b ,c1 ,d ,e1 the increased arcs traveled as the pallet arms lengthen introduce elements of friction which counterbalance and in some cases exceed the advantage gained by increasing the length of the lever used to propel the pendulum4 ,similarly1 the too short armed escapements were found to cause increased difficulty from faulty fitting of the pivots and their holes1 and other errors of workmanship1 which errors could not be reduced in the same proportion as the arms were shortened1 so that it has been determined by practice that a pallet embracing ninety degrees1 or one-fourth of the circumference of the escape wheel1 offers perhaps the best escapement of this nature that can be made4 ,therefore the factories generally now make them in this way4 ,but as many clocks are coming in for repair with greater or less arcs of escapement and the repairers must fix them satisfactorily1 we will begin at the beginning by explaining how to make the escapement of any angle whatever1 from one tooth up to #adj degrees1 or nearly half of the escape wheel4 ,it is quite a common thing for some workmen to imagine that in making an escapement1 the pallets ought to take in a given number of teeth1 and that the number which they suppose to be right must not be departed from2 but there seems to be no rule that necessarily prescribes any number of teeth to be used arbitrarily4 ,the nearer that the center of motion of the pallets is to the center of the escape wheel1 the less will be the number of teeth that will be embraced by the pallets4 ,fig4 #bh is an illustration of the distances between the center of motion of the pallets and the center of the wheel required for #c1 #e1 #g1 #i and #aa teeth in a wheel of the same size as the circle2 but although we have adopted these numbers so as to make a symmetrical diagram1 any other numbers that may be desirable can be used with equal propriety4 ,all that is necessary to be done to find the proper center of motion of the pallets is first to determine the number of teeth that are to be embraced1 and draw lines 7radii7 from the points of the outside ones of the number to the center of the wheel1 and at right angles to these lines draw other two lines 7tangents71 and the point where they intersect each other on the line of centers will be the center of motion of the pallets4 ,illustration3 ,fig4 #bh4 ,illustration3 ,fig4 #bi4 ,note the difference in length of arc for the same angle4 ,it will be seen by the diagram1 ,fig4 #bh1 that by this method the distance between the centers of motion of the pallets and that of the scape wheel takes care of itself for a given number of teeth and that it is greater when eleven and one-half teeth are to be embraced than for eight or for a less number4 ,these short pallet arms are imagined by some workmen to be objectionable1 on the supposition that it will take a heavier weight to drive the clock2 but it can easily be shown that this objection is altogether imaginary4 ,now1 bearing in mind the principles of leverage1 if the distance between the pallets and escape wheel centers is very long1 as in ,graham's plan1 in which the pallets embraced #ach of the escape wheel1 the value of the impulse received from the scape wheel and communicated through the pallets to the pendulum is no doubt greater with a proper length of verge wire1 for1 the lifting planes being longer1 the leverage is applied to the pendulum for a longer arc of its vibration1 yet we must not suppose that from this fact the clock will go with less weight1 for it is easy to see that the longer the pallet arms are the greater will be the distance the teeth of the escape wheel will have to move 7run7 on the circular part of the pallets4 ,see ,fig4 #bi4 ,the extra amount of friction1 and the consequent extra amount of resistance offered to the pendulum1 caused by the extra distance the points of the teeth run on the circular locking planes of the pallets and back again1 destroys all the value of the extra amount of impulse given to the pendulum in the first instance by means of the long arms of the pallets4 ,the escape wheel tooth resting on the locking plane of the pallet is quite variable in its effective action1 and since it rests on the pallet during a part of each swing of the pendulum and the pendulum is called on to move the pallet back and forth under the tooth1 any change in the friction between the tooth and pallet is felt by the pendulum and when the clock gets dirty and the friction between the tooth and pallet is increased1 the rate of the clock gets slow1 as the friction holds the pendulum from moving as fast as it would without friction4 ,now1 as this friction increases by dirt and thickening of the oil1 all these forms of escapements are subject to changes and so change the clock's rate4 ,an increase of the driving weight1 or force of the mainspring1 of clocks with dead-beat escapements always tends to make their rate slow1 from the action mentioned4 ,it is for this reason that moderately short arms are used in clocks having dead-beat escapements of modern construction4 ,most of the first-class modern makers of astronomical clocks only embrace seven and one-half teeth1 on a #cj-tooth wheel1 with the centers of motion of the pallets and scape wheel proportionately nearer1 as it can be mathematically demonstrated that with the pallets embracing an arc of #ij the application of the power to the pendulum is at right angles to the rod and therefore is most effective4 ,,to ,,draw ,,the ,,escapement4--,in order to make the matter clearer we show in ,fig4 #cj the successive stages of drawing an escapement and also the completed work in ,figs4 #cb and #cc embracing different numbers of teeth4 ,draw a line1 ,a ,b1 ,fig4 #cj1 to serve as a basis for measurements4 ,with a compass draw from some point ,c on this line a circle to represent the diameter of our escape wheel4 ,now we shall require to know how many teeth there will be in our escape wheel4 ,there may be #fj1 #dj1 #cc1 #cb1 #cj1 or any other number we desire to give it2 seconds pendulums generally have #cj teeth in this wheel1 because this allows the second hand to be mounted directly on the escape wheel arbor and thus avoids complications4 ,we divide the number of degrees in a circle 7#cfj7 by the number of teeth we have selected1 say #cj4 #cfj #cj #ab for each tooth and space4 ,one-fourth of #cfj equals #ij and one-fourth of #cj teeth equals seven and one-half teeth2 each tooth equaling #ab degrees1 we have #ab #g #hd1 which gives us six degrees for drop1 to ensure the safety of our actions4 ,illustration3 ,fig4 #cj4 ,we now take #ij and1 dividing it1 set off #de each side of our center line and draw radii1 ,r1 from the center to the circumference of our circle2 this marks the beginnings of our pallets4 ,now to find our pallet center distance we draw tangents1 ,t 7at right angles71 from the ends of these radii toward the line of centers4 ,the point where they intersect on the line of centers is the pallet center4 ,now we must determine how much motion we are going to give our pendulum1 so that we can give the proper lift to our pallets4 ,four degrees of swing is usual for a seconds pendulum1 so we will take four degrees and1 dividing it1 give two degrees of lift to each pallet4 ,to do this we draw a line two degrees inside the tangent1 ,t 7towards the escape wheel center71 from our pallet center on the entering pallet side and another line from the pallet center two degrees outside of the tangent1 ,t1 on the exit pallet side4 ,next1 from the pallet center we draw arcs of circles cutting the tangents1 ,t1 and the radii1 ,r1 where they intersect2 this gives us the locking planes on which the teeth of the escape wheel 8run0 7slide7 during the excursions of the pendulum1 if the escapement is to have unequal lockings2 if the lockings are to be equidistant 7if the pallet arms are to be of equal length7 the arc for the entering pallet is drawn three degrees below 7outside7 the radius1 ,r1 while that on the exit pallet is drawn three degrees above 7inside7 the exit radius4 ,finally the lifting planes are drawn from the intersection of the arcs of circles struck from the pallet center with their tangents1 ,t1 to the lines1 marking the limits of the lift1 two degrees away4 ,these lifting planes should be at an angle of #fj from the radii1 ,r1 and as a tangent is always at right angles 7#ij7 to its radius1 they are consequently at #cj to the tangents running to the pallet center4 ,thus we can measure these angles from either the escape wheel or the pallet center1 as may be most convenient4 ,when making a new pallet fork1 it is most convenient to mark out the lifting planes on the steel at #cj from the tangents1 ,t1 as we then do not have to bother with the escape wheel further than to get its center distance and the degrees of arc the lifting planes are to embrace4 ,the workman who is not familiar with this rule is apt to have his ideas upset at first by the angles of inclination toward the center line which the lifting planes will take for different center distances1 as owing to the fact that the tangents meet on the center line at different angles for different distances1 the lifting planes assume different positions with regard to the center line and he may think that they do not 8look right40 ,they are right1 however1 when drawn at #cj to their tangents4 ,fig4 #ca shows several pallets with different arcs arranged in line for purposes of comparison1 each being drawn according to the above rule1 as measurements with a protractor will show4 ,illustration3 ,fig4 #ca4 ,we have now arrived at the complete escapement1 having finished our pallets4 ,we have1 however1 nothing to hold them in position2 they must be rigidly held in position with regard to each other and the escape wheel1 consequently we will make a yoke to connect them to the pallet arbor out of the same steel1 giving it any desired shape that will not interfere with the working of the clock4 ,two of the most usual forms are shown at ,figs4 #cb and #cc4 ,illustration3 ,fig4 #cb4 ,illustration3 ,fig4 #cc4 ,let us see how this rule will work in repairs4 ,suppose we have a clock brought in with the pallet fork missing1 and that the movement is one of those in which the pallet arbor is held by adjustable cocks which have been misplaced or lost1 so that we don't know the center distance of the pallet arbor and escape wheel4 ,we shall have to make a new part4 ,measure the escape wheel1 getting its diameter carefully1 take half of this as a radius1 and mark out the circle with a fine needle point on some copper1 brass or sheet steel1 drawing the escapement as detailed in ,figs4 #cj and #cb4 ,then measure carefully the angles made by the tangents with the center line2 take the steel which is to be used in making the pallets and fork2 draw on it a center line2 lay off the tangents and the lift lines2 draw the locking arcs and the lifting planes carefully from the tangents and give the rest of the fork a symmetrical shape4 ,use needle points to draw with and have your protractor large enough to measure your angles accurately4 ,then drill or saw out and file to your lines1 except on the locking and lifting planes2 leave these large enough to stand grinding or polishing after hardening4 ,harden2 draw to a straw color and polish the planes4 ,your verge will fit if it has not warped in hardening4 ,if this is the case1 soften the center1 keeping the heat away from the pallets1 and bend or twist the arms until the verge will fit the drawing1 when laid on top of it4 ,in grinding the pallets the fork should be mounted on its arbor and the latter held between the centers of a rounding-up tool while the grinding is done by a lap in the lathe4 ,this insures that the planes will be parallel to the pallet arbor and hence square with the escape wheel teeth1 so that they will not create an end thrust on either escape or pallet arbor4 ,it is also the quickest1 easiest and most reliable way of doing the job4 ,when clocks come in with the pallets badly cut2 soften the center of the fork1 place the ends between the jaws of a vise1 squeeze enough to bring them closer1 mount in the rounding-up tool and lap off the cut planes until they are smooth and stand at the proper angle2 then polish4 ,this is done quickly4 ,illustration3 ,fig4 #cd4 ,drawing escape wheel to fit a tracing from a pallet fork4 ,can we work the rule backwards8 ,suppose we get a clock in which we have the pallet arbor adjustable as before1 and we have the pallet fork all in good shape1 but we have lost the escape wheel1 or it has been butchered by somebody before coming to us1 so that a new one is required4 ,take off the pallet fork2 lay it on a sheet of brass and trace around it carefully with a needle point4 ,fig4 #cd4 ,mark the center carefully at the pallet arbor hole and measure carefully the distance between the pallets and mark that center4 ,draw a center line cutting these centers and extending beyond4 ,now draw the tangent from the beginning of the entering pallet 7as shown by the tracing on our brass7 to the pallet center2 do the same with the exit pallet4 ,now take a metal square and place it on one of the tangents exactly1 with the end at the beginning of the entering pallet2 trace a line cutting the line of centers and we have the radius of our escape wheel4 ,trace a circle from the intersection of the radius and the center line and we have the circumference of our escape wheel4 ,this circle should also cut the intersection of the tangent and radius on the other side if it is drawn correctly2 if it does not do this an error has been made in the drawing4 ,illustration3 ,fig4 #ce4 ,drawing an escape wheel to cut4 ,the last drawing shows the complete wheel4 ,having found the diameter and circumference of our escape wheel it may be sawed out and mounted for wheel cutting2 or1 if we have no wheel cutter and must make the wheel1 we must draw it on the brass by hand with a fine needle point before proceeding to saw it out by hand1 ,fig4 #ce4 ,say that the wheel is to have thirty-two teeth1 which is a common number2 then #cfj #cb #aa as the space between the points of our teeth4 ,take a large protractor1 one with the degrees large enough to be divided 7,i use a ten inch72 place its center on the center of our escape wheel1 set off #aa and mark them on the brass with the needle point1 at the edge of the protractor4 ,then take a straight edge and draw a radius from the center to the circumference2 change the straight edge to the other mark and mark the point where it crosses the circumference2 set your dividers accurately by this mark and space off the teeth on your circumference4 ,if they are set at eleven degrees and fifteen minutes they will come out exactly at the end4 ,now take your protractor and with its center at the junction of the radius and circumference set off ten degrees and draw a line past the center of the wheel2 set off twenty degrees and draw another line the same way4 ,from the center of the escape wheel draw two circles just touching these lines4 ,outside of these draw two circles defining the inner and outer edges of the rim of the wheel4 ,with the straight edge just touching the inner circle draw in the fronts of the teeth2 these will all be set at ten degrees from a radius1 so that only the extreme points will touch the locking planes of the pallets and thus reduce the friction during the run4 ,the backs of the teeth are marked out in the same way from the twenty-degree circle4 ,the hub is made to coincide with the ten-degree circle2 the spokes are traced in and we are ready to begin sawing out4 ,if the workman has a wheel cutter the job is much simpler4 ,a piece of brass is mounted on a cement brass with soft solder1 faced off1 centered and the pitch circle1 inner and outer edges of the rim and the hub are traced with the ,t-rest and graver4 ,the extra metal is then cut away and a suitable index placed on the spindle and locked4 ,the wheel cutter is set up with a fine-toothed1 smooth cutting saw on the spindle1 horizontal1 with its upper edge at the line of centers of the lathe4 ,it is then run out to the circumference of the wheel1 turned upwards ten degrees and the wheel cut around1 ,fig4 #cf4 ,this makes the fronts of the teeth4 ,turn the saw ten degrees more and cut the backs of the teeth4 ,then turn the saw so that it will reach from the front of one tooth to the root of the back of the next one1 without touching either tooth1 and cut round again2 this cuts out a triangular piece of waste metal between the teeth4 ,turn the saw again so that it reaches from the bottom of the front of a tooth to the top of the back of the next one and cut around again1 thus removing another portion of the waste metal1 and leaving only a small triangle between the teeth4 ,lower the saw its own thickness and cut around the wheel again1 repeating the operation until the waste metal is all removed and you have a smooth circular rim between the teeth1 ,fig4 #cf4 ,illustration3 ,fig4 #cf4 ,making an escape wheel with a saw1 showing the successive cuts4 ,set the saw horizontally at the lathe center2 raise it one-half the thickness of the spokes2 set the index pin of the lathe head firmly at ,o2 feed in the saw the thickness of the wheel and make straight cuts across from the circle of the inner rim to the circle marking the hub1 but not cutting either2 set the index pin at #cj and repeat2 next lower your saw and cut the other side of the spokes the same way4 ,next you can mount a lap in place of the saw and smooth the fronts and backs of the teeth and if you have a rather thick disc the outer edge of the rim1 between the teeth1 may also be smoothed4 ,if you have a good strong pivot polisher1 mount a triangular end mill in the spindle1 lock the yoke1 and cut the arcs of circles of the hub and rim from edge to edge of the spokes1 feeding carefully against the mill with the hand on the lathe pulley4 ,put on your jeweling tailstock and open the wheel to fit the pinion1 collet1 or arbor1 if there is no collet4 ,you now have the wheel all done1 except facing the side that was soldered to the cement brass and trimming up the corners of the spokes at the rim and hub1 and you have got it round1 true and correct in much less time than you could have done in any other way1 while an immense amount of work with the file and eye-glass has been avoided4 ,it is true because it was soldered in position at the beginning and has not been removed until finished4 ,sometimes what are known from their appearance as club-shaped teeth are used in the wheels of ,graham's escapements4 ,pendulums receive their impulse from escapements made in this manner partly from the lifting planes on the pallets1 and partly from the planes on the scape wheel4 ,the advantage gained by this method is1 that wheels made in this way will work with the least possible drop1 and consequently1 power is saved2 but the power saved is thrown away again in the increased friction of the planes of the wheel against those of the pallets1 which is considerably more than when plain-pointed teeth are used on the escape wheel4 ,clock pallets are usually made of steel1 and on the finer classes of work jewels are often set into them to prevent the oil from drying1 after the same fashion as jewels are placed in steel pallets in a lever watch2 but it is obvious that stone pallets made in this way have to be finished with polishers held in the hand1 and that1 except in factories1 they cannot be made so perfectly regular1 especially that pallet that is struck downwards1 as the particular action of a fine ,graham escapement requires4 ,when great accuracy is required1 the pallets are usually made of separate pieces1 and the acting circles ground and polished on laps1 running in a lathe4 ,this method of constructing pallets also allows a means of adjustment which in some particular instances is very convenient4 ,there is also a plan of making jeweled pallets adjustable1 which is practiced on fine work1 such as astronomical and master clocks4 ,the pallet fork consists of two pieces of thin1 hard1 sheet brass1 cut out in the usual form and two mounted on one arbor4 ,circular grooves are cut in the sides of both plates1 at the proper distance1 and of the proper size to receive the jewels which are the acting parts of the pallets4 ,when jewels cannot be made of the desired size1 pallets of steel are made1 and the jewels are then set into the steel large enough for the teeth of the wheel to act upon4 ,the two parts of the fork are fastened at a given distance apart1 and the jewels1 or pieces of steel1 go in between them1 and1 after they have been adjusted to the proper position1 are fastened by screws that pull the frames close together and press against the edges of the jewels4 ,pallets made in this manner have a very elegant appearance4 ,another method is to have only one frame1 and to have it thick enough1 where the jewels have to be set in1 to allow a groove to be cut in its side as deep as the jewels 7or the pieces of steel that hold the jewels7 are broad1 and which are held in their proper position by screws4 ,this system of jeweling pallets is frequently adopted by the makers of fine mantel clocks4 ,illustration3 ,fig4 #cg4 ,brocot's visible escapement1 escaping over #abj with pointed teeth4 ,dotted lines on pallets show where they are cut to avoid stopping4 ,,brocot',s ,,visible ,,escapement4--,fig4 #cg represents a system of making and jeweling pallets much used by the ,french in their small work1 especially in visible escapements4 ,the acting parts of the pallets are simply cylinders1 generally of colored stones1 usually garnets1 one-half of each cylinder being cut away4 ,these cylinders extend some distance from the front of the pallet frame1 and work into the escape wheel the same as the pallets of a ,graham escapement--the round parts of the pallets serving as impulse planes4 ,the neck of the brass pallet frame is cut up in the center1 and the width between the pallets is sometimes adjusted by a screw1 sometimes by bending the arms4 ,clock movements with this escapement1 of a careful construction1 will frequently come for repairs1 accompanied by the complaint of constant stopping and that no attempt at closely regulating can succeed with them1 although they appear to have no visible disturbing cause4 ,in such cases the depthing of the escapement is generally wrong4 ,with proper depthing the point of the escape wheel tooth should drop on the center or a little beyond the center of the pallet stone4 ,if it is set in this way the clock will stop when wound1 especially if it has a strong spring1 as the light pendulum will not then have momentum enough to unlock it against the full power of the spring4 ,if the pallets are set shallow1 in order to avoid this difficulty1 then1 the pendulum will take too short a swing and thus the clock will have a gaining rate4 ,generally the pendulum ball cannot be made enough heavier to correct the defect4 ,illustration3 ,fig4 #ch4 ,brocot's visible escapement escaping over #ij with a small lift on the escape wheel teeth4 ,in these movements1 in which the length of the pendulum does not exceed #d inches1 the pallet fork embraces1 generally about #abj1 or the one-third part of the wheel2 it will be seen that unless there are stop works on the barrel of the main spring no manner of regulating is possible with these conditions1 in view of the considerable influence exercised by the mainspring through the train on the very light pendulum1 and by replacing this unduly high anchor by a lower one1 ,i have always been able to produce a very satisfactory rate with movements having pendulums of three and a half to four inches4 ,fig4 #ch shows a #ij escapement with a small lift on the escape wheel teeth4 ,in spite of its incontestable qualities1 the visible escapement possesses one inherent fault4 ,i refer to the formation of its pallets1 the semi-circular shape of which renders unequal the action of the train in giving impulse to the pendulum exceeding #ej centimeters 7#bj inches71 since to make it to describe arcs of from one to two degrees only1 with pendulums of from #fj centimeters to one meter in length1 it became necessary to make the anchor arms extremely long1 which considerably impeded the freedom of action1 especially when the oil became thick1 and this disposition would1 therefore1 stand in direct contradiction with the principles of modern horology4 ,both stopping and the irregularity of rate can be obviated by changing the semi-circular form of the pallets for one of an inclined plane1 either by grinding a new plane or turning the stones in such manner as to offer an inclined plane to the action of the wheel1 analogous to that of the ,graham escapement4 ,see ,fig4 #cg1 the dotted lines on the pallets showing the portion to be ground away4 ,the importance of this transformation will readily be understood2 it suffices to give to these planes a more or less large inclination in order to obtain a greater regularity of lifting1 and1 at desire1 a lifting arc more or less considerable without being compelled to modify the proportions of the fork or to exaggerate the center distance of wheel and pallet arbor4 ,in adjusting an escapement1 perhaps it may be advisable to mention that moving the pallets closer together1 or opening them wider1 will only adjust the drop on one side1 while the other drop can only be affected by altering the distance between the centers of the pallets and scape wheel4 ,this is accomplished in various ways4 ,the ,french method consists of an eccentric bush1 riveted in the frame just tight enough to be turned by a screwdriver4 ,another plan1 common in ,america1 is simply pieces of brass 7cocks7 fastened on the sides of the frames4 ,the pivots of the pallet axis are hung in holes in these cocks1 and an adjustment of great accuracy may be quickly obtained by loosening the clamping screws4 ,lock1 drop and run should be of the same amount on each pallet4 ,however1 we do not approve of adjustments of any kind1 except in the very highest class of clocks1 where they are always likely to be under the care of skillful people1 who understand how to use the adjustments to obtain nicety of action in the various parts4 ,in making escapements1 lightness of all the parts ought to be an object always in view in the mind of the workman1 and such materials should be used as will best serve that purpose4 ,the scape wheel1 and the pallets and fork1 should have no more metal in them than is necessary for stiffness4 ,the pallet arbor1 and also the escape wheel arbor1 should be left pretty thick when the wheel and pallets are placed in the center between the plates1 to prevent their springing when giving impulse to the pendulum4 ,we have often been puzzled to find out the necessity or the utility of placing them in the center between the plates1 as they are so generally done in ,english clockwork4 ,the escapement acts much more firmly when it is placed near one of the plates1 and it is just as easy to make it in this way as in the other4 ,it is often assumed that the friction of the teeth on the circular part of the pallets of a dead-beat escapement is small in amount and unimportant in its value4 ,with respect to its amount1 we believe it is often not far short of being equal to one-half of the combined retarding forces presented to the pendulum2 and with respect to its being unimportant1 this assumption is founded on the supposition that it is always a uniform force1 when it is easy to show that it is not a uniform force4 ,it is very well known that the force transmitted in clock trains1 from each wheel to the next1 is very far from being constant4 ,small defects in the forms of the teeth of the wheels and of the leaves of the pinions1 and also in the depths to which they are set into each other1 cause irregularities in the amount of power transmitted from each wheel to the next2 and the accidental combination of these irregularities in a train of four or five wheels1 makes the force transmitted from the first to the last exceedingly variable4 ,the wearing of the parts and the change in the state of the oil1 are causes of further irregularities2 and1 from these causes1 it must be admitted that the propelling power of the scape wheel on the pallets is of a variable amount1 and a more important question for consideration than it is usually supposed to be4 ,to avoid the consequences of this irregular pressure of the scape wheel on the pallets being communicated to the pendulum1 is a problem that has puzzled skillful mechanicians for many years2 for1 although we find the ,graham escapement to be pronounced both theoretically and mechanically correct1 and by some authorities little short of perfection1 we find some of these same authorities--both theoretically and practically--testify their dissatisfaction with it by endeavoring to improve on it4 ,in ,europe the experience of generations and the expenditure of small fortunes1 in pursuit of this improvement1 through the agency of the gravity1 and other forms of escapements1 proves this fact2 while of late years1 in the ,united ,states1 much time and money has been spent on the same subject1 and results have been reached which have raised questions that ten years ago were little dreamed of by those clockmakers who are generally engaged on the highest class of work4 ,while considering this class of escapements1 we would say a few words in regard to the sizes of escape wheels generally used4 ,small wheels can now be cut as accurately as larger ones and there is now no reason or necessity for continuing the use of a wheel of the size ,graham and ,le ,paute used1 and which has been the size generally adopted by most ,european makers who use these escapements4 ,the ,germans and ,swiss make wheels much smaller for ,graham escapements than the ,english makers do2 and the ,american factories make them smaller still4 ,on the continent of ,europe the wheels of ,le ,paute's escapement are made much larger than they are made in ,england and in the ,united ,states4 ,no wheel1 and more especially a scape wheel1 should be larger than will just give sufficient strength for the number of teeth it has to contain1 in proportion to the amount of work that it has to perform4 ,the amount of work a scape wheel has to perform in giving motion to the pendulum is of the lightest description1 and not more than one-tenth of what it is popularly supposed to be1 which is shown by its variation under slight increase of friction2 therefore we do not consider that we take extreme ground in recommending wheels for these escapements to be made nearly half the size their originators made them1 and the pallets drawn off in proportion to the reduced size of the wheel4 ,it is plain that by reducing the size of the wheel its inertia will be reduced4 ,when the teeth begin to act on the inclined planes of the pallets1 the wheel will be set in motion with greater ease1 as it has a shorter leverage1 and the amount of the dead friction of the scape wheel teeth on the inclined planes and circular part of the pallets will also be proportionately reduced by making the wheel smaller4 ,factory experience and examination of a large number of clocks in repair shops have also shown that smaller and thicker escape wheels will wear much longer than larger and thinner ones1 as all the wear is at the points of the teeth and this is the portion to be protected4 ,,chapter ,,ix4 ,,le ,,paute',s ,,pin ,,wheel ,,escapement4 ,probably in no other escapement1 except the lever1 has there been so many modifications as in the pin wheel2 this is so to such an extent that it will be found by the student that nearly every escapement of this kind which he will examine will differ from its fellows if it has been made by a different maker4 ,they will be found to vary in the lengths of the pallet arms from three-fourths to one and a half times the diameter of the escape wheel2 some of them will have the longer arm of the pallets outside and some inside2 some will have the lift for both pallets laid out on one side of the perpendicular ,p1 ,fig4 #ci1 while others will have the lift divided1 with the perpendicular in the center4 ,very old escapements have the pallet center directly over the escape wheel center1 while the pallet arms work at an angle of #de1 while others have them with the pallet center planted on a perpendicular1 tangent to the pitch line of the escape wheel4 ,some have the circular rest or locking faces of the pallets rounded slightly to hold the oil in position while others have them flat and still others have them made of hard stone1 polished4 ,more than half have the pins in the escape wheel cut away for one-half of their diameters1 leaving the bottoms round1 as shown in ,fig4 #ci1 while others use a wider pin and trim away the bottoms also1 as in ,fig4 #dj1 leaving the lifting surface on the pins not more than one-fourth the arc of the circle4 ,this is especially true of the larger escapements used in tower clocks1 though they are also found in regulators4 ,illustration3 ,fig4 #ci4 ,pin ,wheel ,escapement4 ,illustration3 ,fig4 #dj4 ,pin ,wheel ,with ,flattened ,teeth4 ,in view of the wide variation in practice1 therefore1 we have endeavored to present in ,fig4 #ci a conservative statement of the general practice as found in existing clocks4 ,we say existing1 because very few of these escapements are made now--none at all in ,america--and those in use are generally in imported regulators1 which have come from ,switzerland or ,germany4 ,the ,waterbury ,clock ,co4 at one time made this escapement for its regulators and the ,seth ,thomas ,clock ,company made a number of its early tower clocks with it1 but both have discontinued it for some years1 and it is safe to say that any movement coming into the watchmaker's hands which has this escapement is imported2 or if ,american1 it is out of the market4 ,le ,paute claimed as an advantage the fact that the impact of the escape wheel teeth is downward on both pallets1 whereas in the gravity and recoil escapements one blow is struck upwards and the other downwards4 ,he claimed that by this means a better action was secured after the pivot holes began to wear1 as there was less lost motion with both blows in the same direction and any shake would not affect the amount of impulse given to the pendulum4 ,the difference is more theoretical than practical1 however1 and the escapement possesses one serious fault1 which is that the pins forming the escape wheel teeth conduct the oil away from the pallets1 so that the clock changes its rate in from eight months to one year after being oiled and cleaned4 ,the most effective means of counteracting this is to round the locking planes of the pallets slightly1 so that the oil will be held on them by capillary attraction4 ,another method is to turn the pins so that they are thicker in diameter at the point of contact with the pallets1 but this is seldom tried4 ,the best plan is to keep the pallets as close as they can be to the face of the wheel without touching4 ,,to ,,draw ,,the ,,escapement4--,in laying out this escapement the first thing to consider is the arc of swing of the pendulum1 because one-half of the lift is on the pin and consequently one-half the lift must equal one-half the diameter of the pin1 as shown in ,fig4 #ci4 ,if the pendulum swings four degrees1 then the diameter of each pin must equal four degrees of the pallet movement4 ,this establishes the size of our pin2 it is measured from the pallet staff hole4 ,there are #cj of these pins for a second's pendulum1 and unless it is a very large escapement the pins cannot be made less in diameter than one-fourth the distance between the pins1 or they will be too weak and will spring2 consequently #cfj #cj #ab and #ab #d #c1 so that three degrees of the pitch line of the escape wheel equals the swing of the pallet fork4 ,this establishes the relation as to size between the escape wheel and the opening1 or swing of the pallet fork4 ,draw a perpendicular1 ,p1 from the pallet center and on one side of it lay out the lift lines ,l1 ,l2 draw a line at right angles to the perpendicular and where it crosses the inner lift line draw a circle touching the outer lift line4 ,the diameter of this circle equals three degrees of the circumference of the wheel1 on its pitch line1 and this multiplied by #abj gives #cfj or the pitch circumference of the escape wheel4 ,dividing the sum so found by #c4adaf gives the diameter of the escape wheel and half of this is the radius4 ,after finding the radius draw the pitch circle and set out the other twenty-nine teeth spaced twelve degrees apart1 and drawn in half circles as shown in ,fig4 #ci4 ,now to get the thickness of the pallet arms4 ,when the pin shown in action in ,fig4 #ci has just cleared the lower edge of the inner pallet1 the succeeding pin should fall safely on the upper corner of the outer pallet2 consequently the thickness of these two arms1 the pin between them1 and the drop 7clearance between the pin and the lower edge of the upper pallet7 should just equal the distance between two pins1 from center to center1 or #ab of the escape wheel4 ,with the first or inner lift line as a starting point1 draw the lower arcs of the pallets and draw the upper or locking planes from the perpendicular and the outer lift line4 ,then draw the lifting planes of the pallets by connecting the ends of these arcs4 ,the enlarged view above the escape wheel in ,fig4 #ci will show how this is done more clearly than the main drawing4 ,it is best to make the pallet fork of steel1 in two pieces1 screwed to a collet on the pallet arbor1 as the inner arm must be bent1 or offset1 so that it will clear the pins of the escape wheel1 and the pallets should lie in the same plane1 as close to the wheel as is possible without touching it4 ,the pallets are hardened4 ,in tower clocks the escapement is so large that a pin having a diameter of three degrees of the escape wheel gives a half pin of greater strength than is necessary for the work to be done and such pins are cut away on the bottom1 as in ,fig4 #dj4 ,in making the wheel it should be drilled in the lathe with the proper index to divide the wheel and the pins riveted in2 then the pins are cut with a wheel cutter as if they were teeth of a wheel4 ,pins should be of hard brass4 ,care should be used in handling clocks with this escapement while the pendulum is connected with the pallet fork1 as1 if the motion of the fork should be reversed while a pin was on one of the lifting planes1 it would bend or break the pin4 ,,chapter ,x4 ,,the ,,recoil ,,or ,,anchor ,,escapement4 ,this escapement1 always a favorite with clockmakers1 has had a long and interesting history and development4 ,because it started with a suddenly achieved reputation1 and because it is adapted to obtain fair results with the cheapest and consequently most unfavorable working conditions1 it has won its way into almost universal use in the cheaper classes of clock work2 that is to say1 it is used in about ninety per cent of the pendulum clocks which are manufactured to-day4 ,it achieved a sudden reputation at its birth1 because it was designed to replace the old verge1 which1 with its ninety degree pallets close to the arbor1 and working into the crown wheel1 required a very large swing of the pendulum4 ,this necessitated a light ball1 a short rod1 required a great force to drive it1 and made it impossible to do away with the circular error1 while leaving the clock sensitive to variations in power4 ,the recoil escapement was therefore the first considerable advance in accuracy1 as its use involved a longer and heavier pendulum1 shorter arcs of vibration and less motive power than was practicable with the verge2 and as the pendulum was less controlled by the escapement1 it was less influenced by variations of power4 ,in the early escapements the entrance pallet was convex and the exit pallet concave4 ,escapements of this description may still be met with among the antiquities that occasionally drift into the repair shop4 ,later on both pallets were made straight1 as shown in ,fig4 #da4 ,it will be seen by studying the direction of the forces that the effect is to wear off the points of the teeth very rapidly1 and for this reason the pallets were both made convex 7,see ,fig4 #db71 so as to bring the rubbing action of the recoil more on the sides of the teeth and do away to a large extent with the butting on the points which destroyed them so rapidly4 ,illustration3 ,fig4 #da4 ,recoil ,escapement with ,straight ,lifting ,planes4 ,the rather empirical methods of laying out the recoil escapement1 which have gained general circulation in works on horology1 have had much to do with bad depthings of this escapement and the consequent undue wear of the escape wheel teeth and great variation in timekeeping of the movements in which such faulty depthings occur1 particularly in eight-day movements with short and light pendulums4 ,the escapement will invariably drive the clock faster for an increase of power and slower for a decrease2 an unduly great depthing will greatly increase the arc of vibration of the pendulum1 as the train exerts pressure on the pendulum for a longer period during the vibration2 the consequence is that instead of the pendulum being as highly detached as possible1 we have the opposite state of affairs and a combination of a strong spring1 light pendulum and excessive depthing will easily make a variation of five minutes a week in an eight-day clock4 ,the generally accepted method of laying out this escapement is shown in ,figs4 #da and #db1 as follows3 8,draw a circle representing the escape wheel2 multiply the radius of the escape wheel by #a4d and set off this as the center distance between the pallet and escape wheel centers4 ,from the pallet staff center describe a circle with a radius equal to half the distance between escape wheel and pallet centers4 ,set off on each side of the center line one-half the number of teeth to be embraced by the pallets and from the points of the outside teeth draw lines tangent to the circle described from the pallet center4 ,these lines would then form the faces of the pallets if they were left flat40 ,we wonder how much information this description and the drawing conveys to the average reader4 ,how long should the pallets be8 ,what is the drop8 ,how much will the escape wheel recoil with such a depthing8 ,what arc will the pallets give the pendulum8 ,why should the center distance always be the same 7seven tenths of the diameter of the wheel7 whether the escapement embraces eight1 or ten1 or six teeth8 ,as a matter of fact it should not be the same4 ,we could ask a few more questions as to other details of this formula1 but it will be seen that such a description is practically useless to all but those who are already so skilled that they do not need it4 ,illustration3 ,fig4 #db4 ,recoil ,escapement with ,curved ,lifting ,planes4 ,illustration3 ,fig4 #dc4 ,drawing the ,lock ,lift and ,recoil of the ,usual ,form4 ,let us analyze these drawings4 ,a little study of ,figs4 #da1 #db and #dc will show that there is really only one point of difference between them and ,fig4 #cb1 which shows the elements of the ,graham1 or dead beat4 ,the sole difference is in the fact that there are no separate locking planes in the recoil1 the locking and run taking place on an extension of the lifting planes4 ,otherwise we have the same elements in our problem and it may therefore be laid out and handled in the same manner2 indeed1 if we were to set off on ,fig4 #cb1 the amount of angular motion of the pallet fork which is taken up by the run of the escape wheel teeth on the locking planes1 by drawing dotted lines above the tangents1 ,t1 we should then have measured all the angles necessary to intelligently set out the recoil escapement4 ,we should have the lock at the tangent1 ,t1 the lift and the run 7or recoil7 being defined by the lines on either side of it1 and the length of our running and lifting planes would be found for the entering pallet by drawing a straight line between the points of the two acting teeth of the escape wheel and noting where this line cut the lines of recoil and lift4 ,a similar line traced at right angles to this would in the same way define the limits of run and lift on the exit pallet4 ,it will therefore be seen that our center distances for any desired angle of escapement may be found in the same way 7,fig4 #bh71 for either escapement1 and thus the method of making the pallets for the ordinary ,american clock1 ,fig4 #dc1 becomes readily intelligible4 ,the sole object of curving the pallets1 as explained previously1 was to decrease the butting effect of the run on the points of the teeth4 ,this is accomplished in ,fig4 #dc by straight planes on the pallets and straight sides to the teeth with #bj teeth on the escape wheel2 merely inclining the plane of the entering pallet about six degrees toward the escape wheel center1 thus serving all purposes1 while the gain in the cost of manufacture by using straight instead of curved pallets and wheel teeth is very great4 ,illustration3 ,fig4 #dd4 ,recoil with ,curved ,planes4 ,illustration3 ,fig4 #de4 ,showing the ,usual ,position in ,cheap ,clocks and the ,verge ,wire4 ,one factory in the ,united ,states is turning out #b1jjj1jjj annually of two movements1 or about #a1jjj1jjj of each movement2 there are four other larger factories and several with a less product2 so it will readily be seen that any decrease in cost1 however small it may be on a single movement1 will run up enormously on a year's output4 ,suppose the factory mentioned were enabled to save only one-eighth of a cent on one of its million movements manufactured last year1 this would amount to #a1bej per year1 a little over #ajj per month4 ,thus it will be seen that close figuring on costs of production is a necessity4 ,illustration3 ,fig4 #df4 ,drum ,escapement4 ,fig4 #dd shows the method of drawing the escapement according to the common sense deductions given above4 ,as the methods of laying out the angle of escapement1 lock1 lift1 and run1 were given in detail in ,figs4 #bh to #cb1 they need not be repeated here4 ,fig4 #df shows the escapement frequently used in ,french 8drum0 clocks and hence called the 8,drum0 escapement4 ,these are clocks fitted to go in any hole of the diameter of the dial and hence they have very short1 light pendulums4 ,an attempt is made to gain control over the pendulum by decreasing the arc of escapement to not more than two and sometimes to only one tooth4 ,this gives an impulse to the pendulum only on one-half of the vibrations1 the escape wheel teeth resting and running on the long circular locking pallet during alternate swings of the pendulum4 ,the idea is that the friction of the long lock will tend to reduce the effect of the extra force of the mainspring when the clock is freshly wound4 ,such clocks often stop when the clock is nearly run down1 from deficiency of power1 and stop when wound1 because the friction of the escape wheel teeth on the locking plane is such as to destroy the momentum of the light pendulum4 ,all that can be done in such cases is to alter the locking planes as shown by the dotted lines1 so that the 8drum0 becomes virtually a recoil escapement of two teeth4 ,,chapter ,,xi4 ,,the ,,dennison ,,or ,,gravity ,,escapement4 ,the distinguishing feature of this escapement lies in the fact that it aims to drive the pendulum by applying to it a falling weight at each excursion on each side4 ,as the weight is lifted by the train and applied to the pendulum on its return stroke and there is no other connection1 it follows that the pendulum is more highly detached than in any other form of pendulum escapement4 ,this should make it a better timekeeper1 as the application of the weight should give a constant impulse and hence errors and variations in the power which drives the train may be neglected4 ,on tower clocks this is undoubtedly true1 as these clocks are interfered with by every wind that blows against the hands1 so that a detached pendulum enables a surplus of power to be applied to the train to meet all emergencies4 ,with a watchmaker's regulator1 however1 the case is different4 ,here every effort is made to favor the clock1 vibrations1 variations of temperature1 variations of power1 dirt1 dust1 wind pressure and irregularities of the mechanism are all carefully excluded and the consequence is that the special advantages of the gravity escapement are not apparent1 for the reason that there are practically no variations for the escapement to take care of4 ,added to this we must consider that the double three-legged form1 which is the usual one1 is practically an escape wheel of but six teeth1 so that another wheel and pinion must be added to the train and this1 with the added complications of the fan and the heavier driving weight required1 counterbalance its advantages and bring it back to an equality of performance with the simpler mechanism of the well made and properly adjusted dead beat escapement4 ,theoretically it should work far better than the dead beat1 as it is more detached2 but theory is always modified by working conditions and if the variations are lacking there is no special advantage in constructing a mechanism to take care of them4 ,this is the reason why so many watchmakers have constructed for themselves a regulator with this escapement1 used in the making all the care and skill of which they were capable and then been disappointed to find that it gave no better results with the same pendulum than the dead beat it was to replace4 ,they had eliminated all the conditions under which the detached escapement would have shown superiority4 ,illustration3 ,fig4 #dg4 ,although the gravity escapement will not give a superior performance under the most favorable conditions for timekeeping1 it is distinctly superior when these conditions are unfavorable and therefore fully merits its high place in the estimation of the horological fraternity4 ,we have instanced its value in tower clock work2 it has another advantage in running cheap and poorly made 7home made7 regulators with rough and poor trains2 therefore1 it is a favorite escapement with watchmakers who build their own regulators while they are still working at the bench1 before entering into business for themselves4 ,as the price of a first-class clock for this purpose is about #cjj and the cheapest that is at all reliable is about #ge1 it will be seen that the temptation to build a clock is very strong and many of them are built annually4 ,regulators with the gravity escapement are built by the ,seth ,thomas ,clock ,co41 the ,howard1 and one or two others in this country1 but they are furnished simply to supply the demand and sales are never pushed for the reasons given previously4 ,clocks with this escapement are quite common in ,england and many of them have found their way to ,america4 ,it is one of the anomalies of trade that our clockmakers are supplying ,europe with cheap clocks1 while we are importing practically all the high priced clocks sold in the ,united ,states and among them are a few having the three-legged and four-legged gravity escapements1 therefore the chances are that when a repairer finds such a clock it is likely to be either of ,english origin or homemade1 unless it be a ,german regulator4 ,figs4 #dg and #dh show plans and side views of the three-legged escapement4 ,fig4 #dh also shows an enlarged view of the escape wheel1 showing how the three-leaved pinion between the two escape wheels1 is made where it is worked out of the solid4 ,a1 ,b and ,c and a1 b and c show the escape wheel which is made up of two three-armed wheels1 one on each side of a three-leaved pinion marked ,d and ,d in the enlarged view of ,fig4 #dh4 ,the pallets in this escapement consist of the two arms of metal suspended from points opposite the point of bending of the pendulum spring and the lifting planes are found on the ends of the center arms in these pallets1 which press against the three leaves of the pinion1 while the impulse pins e and e1 ,fig4 #dg and #dh act directly upon the pendulum in place of the verge wire4 ,the pallets act between the wheels in the same plane as each other4 ,the lifting pins or pinion leaves act on the lifting planes after the line of centers when the long teeth or legs of the escape wheels have been released from the stops1 ,f and ,g1 ,figs4 #dg and #dh1 which are placed one on each side of the pallets and act alternately on the wheels4 ,these pallets are pivoted one on each side of the bending point of the suspension spring4 ,to lay out the escapement1 draw a circle representing the escape wheel diameter1 then draw the line of centers and set off on the diameter of the escape wheel from each side of the line of centers #fj of its circumference1 thus marking the positions for the pallet stops #abj apart4 ,draw radii from the center of the escape wheel to these positions and draw tangents from the ends of these radii toward the center line4 ,the point where these meet will be the bending point of the pendulum spring4 ,illustration3 ,fig4 #dh4 ,this is clearly shown at ,h1 ,fig4 #dg4 ,the points of suspension for the pallets are planted on the line of these tangents and a little below the point ,h1 where the tangents meet on the line of centers4 ,this is done to avoid the mechanical difficulty of having the studs for the two pallets occupy the same place at the same time4 ,the arms of the pallets below the stops may be of any length1 but they are generally constructed of the same angle as the upper arms and will be all right if drawn parallel to these upper arms4 ,they are in some instances continued further down1 but this is largely a matter of taste and the lower portion of the escapement is generally drawn so as to be symmetrical4 ,the impulse of the pendulum is given by having pins projecting from the pallet arms and bearing upon the pendulum rod1 which pins may be of brass1 steel or ivory4 ,in the heavier escapements they are made of ivory in order to avoid any chatter from contact with the pendulum rod of a heavy pendulum4 ,these pallets should be as light as it is possible to make them without having them chatter under the impact of the escape wheel arms on the stops4 ,they have only to counteract the force of the pendulum spring and the resistance of the air and for light pendulums this force is much less than is generally understood4 ,two ounces of impulse will maintain a #bej-pound pendulum1 but two pennyweights is more than sufficient for a fifty-pound pendulum4 ,the reader can see that in the case of a pendulum weighing but eight to fourteen pounds1 there will be a still greater proportionate drop1 as the spring itself is thinner1 the rod is thinner1 the pendulum ball offers little resistance to the air and the consequence is that it is difficult to get the pallet arms light enough for an ordinary clock4 ,watchmakers who make this escapement for themselves1 to drive an eight to fourteen pound pendulum1 generally make the escape wheel three inches diameter and make the escape wheel and pallet arms all from the steel obtained by buying an ordinary carpenter's saw4 ,the lifting planes should not be more than one-eighth its diameter from the center of the escape wheel1 as where this is the case the circular motion of the center pins will be so great that the pallet in action will be thrown out too rapidly and will chatter when striking the pendulum rod4 ,on the other hand it should not be less than one-twelfth of the diameter of the escape wheel1 or the pendulum will not be given sufficiently free swing and the motion will be so slow that while such a clock will work under favorable conditions1 jarring1 shaking in wind storms1 etc41 will have a tendency to make the pendulum wabble and stop the clock4 ,from what has been said above1 it will also be seen that the necessity for slow motion of the pallet arms unfits this escapement for use with short pendulums4 ,the action of the escapement is as follows3 ,the pendulum traveling to the right1 when it has thrown the right pallet arm sufficiently far1 will liberate the escape wheel tooth from the stop ,g and the pinion1 acting on the lifting plane1 will raise the pallet arm1 allowing the pendulum to continue its course without doing any further work until it has reached nearly its extreme point of excursion1 when the weight of the pallet will be dropped upon the pendulum rod and remain there1 acting upon the pendulum until it has passed the center when the pallet arm will be stopped by the banking pin ,m2 exactly the same procedure takes place on the left side of the escapement during the swing of the pendulum to the left4 ,the beat pins ,m and ,m should be set so that the impulse pins e and e will just touch the pendulum when the latter is hanging at rest and the escapement will then be in beat4 ,the stops should be cut from sheet steel and the locking faces of the escape wheel arms1 stops on the pallets1 lifting planes of the pallets and the lifting pins should all be hardened4 ,in some of the very fine escapements the faces of the blocks are jeweled4 ,the arms of the inner part of the escape wheel are usually set at equal angular distances between those of the outer1 although this is not absolutely necessary1 and the lifting pins are set on radii to the acting faces of the arms of one of the wheels1 so as to cross the line of centers at the distance from the center1 not exceeding one-eighth of the radius of the wheel1 for the reasons explained above4 ,illustration3 ,fig4 #di4 ,from the comparatively great angle at which the arms are placed1 the distance through which they have to be lifted to give sufficient impulse is less in this escapement than in one with a larger number of teeth acting in the same plane1 as the pallets would then hang more nearly upright4 ,this is a great advantage1 as the contact is shorter4 ,the unlocking is also easier for the same reason1 and from the greater diameter of the wheel in proportion to other parts of the escapement1 the pressure on the stops is considerably less4 ,the two wheels must be squared on the arbor1 so there will be no possibility of slipping4 ,the lifting pins ,d are shouldered between them like a three-tooth lantern pinion4 ,in small escapements the lifting pins are not worked out of the solid arbor1 but are made as hardened screws to connect the two portions of the wheel4 ,in tower clocks the pinion is generally made solid on the shaft ,j1 ,fig4 #dh4 ,the wheel1 ,a1 ,b1 ,c1 is made to pass over the pinion ,d and is fitted to a triangular seat1 the size of the triangle of the leaves1 ,d1 against the collar on the shaft4 ,the other wheel1 a1 b1 c1 is fitted to the inside triangle of the pinion1 so that the leaves1 ,d1 form a shoulder against which it fits4 ,the pallets1 ,e and ,e1 also lie in one plane between the wheels1 but one stop1 ,f1 points forward to receive the ,a1 ,b1 ,c1 teeth and the other1 ,g1 points backward to receive the a1 b1 c teeth alternately4 ,the distance of the pendulum top1 ,h1 or cheeks from the center of the escape wheel1 ,j equals the diameter of the escape wheel4 ,the lifting pins should be so placed that the one which is holding up a pallet and the one which is to lift next will be vertical over each other1 on the line of centers1 the third pin being on the level with the center1 and to one side of it1 see ,fig4 #dh1 enlarged view4 ,the fly is a very essential part of this escapement1 as the angular motion of the escape wheel is such that unless it were checked it would be apt to rebound and unlock2 consequently1 a large fly is always a feature of this escapement and is mounted upon the scape wheel arbor with spring friction in such a way that the fly can continue motion after the scape wheel has been stopped4 ,this is provided for by a spring pressure1 either like the ordinary spring attachment of the fly of striking trains of small clocks1 or as shown in ,fig4 #di for tower clocks4 ,this fly is effective in proportion to its length and hence a long narrow fly will be better than a shorter and wider one1 as the resistance of the air striking against the ends of the fly is much greater the further you get from the center4 ,illustration3 ,fig4 #ej4 ,the pallet stud pins and the impulse pins should on no account be touched with oil or other grease of any kind1 but be left dry whatever they are made of1 because the slightest adhesion between the impulse pins and the pendulum rod is fatal to the whole action of the escapement4 ,care must also be taken that one pallet begins to lift simultaneously with the resting of the other1 neither before nor after4 ,the gravity escapement requires a heavier weight or force to operate the train than a dead beat escapement1 because it must be strong enough to be sure of lifting the pallets quickly and firmly1 and also because the escape wheel having but six teeth necessitates the use of another wheel and pinion between the escape and center and consequently the train is geared back more than it would be for a dead beat escapement1 with the seconds hand mounted on the escape wheel arbor4 ,but with this form of escapement the superfluous force does not work the pendulum and it does no harm if the train is good enough not to waste power in getting over rough places left in cutting the teeth of the wheels or any jamming from those which have unequal widths or spaces4 ,for this reason a high numbered train is better than a low numbered one1 as these defects are greater on the teeth of a low numbered train and any defect in such cases will show itself4 ,in the gravity escapement the escape wheel must have a little run at the pallets before it begins to lift them and in order to do this the banking pins1 ,m1 ,m for the pallet arms to rest on1 should hold them just clear of the lifting pins or leaves of the escape wheel4 ,the escape wheel should be as light as possible1 for every blow heard in the machine means a loss of power and wear of parts4 ,of course1 in an escapement a sudden stop is expected1 but the light wheel will reduce it to a minimum if the fan is large enough4 ,particular attention should therefore be given to the length of this fan and if the stop of the escape wheel seems too abrupt1 the fan should be lengthened4 ,illustration3 ,fig4 #ea4 ,figs4 #ej and #ea show the same escapement with a four-legged wheel instead of the double three-legged4 ,in this case1 where there is but one wheel1 the pallets must of necessity work on opposite sides of the wheel and hence they are not planted in the same plane with each other1 but are placed as close to each side of the wheel as is practicable4 ,to lay out this escapement1 draw the circle of the escape wheel as before1 make your line of centers and mark off on the circle #fg on each side of the line of centers and draw radii to these points1 which will indicate the approximate position of the stops4 ,tangents to these radii1 meeting above the wheel on the line of centers will give the theoretical point of the suspension4 ,one set of the lifting pins is planted on radii to the acting faces of the teeth of the escape wheel4 ,the opposite set1 on the other side of the wheel1 is placed midway between the first set4 ,this secures the lifting at the line of centers4 ,the wheel turns #de at each beat and its arbor likewise carries a fly4 ,in case the locking is not secure1 the stops may be shifted a little up or down1 care being taken to keep them #ace apart4 ,in this way a draw may be given to the locking of the scape wheel arms similar to the draw of the pallets in a detached lever escapement and thus any desired resistance to unlocking may be secured4 ,the stops in either escapement are generally made of steel and it is of the utmost importance that the arms of the escape wheel should leave them without imparting the least suspension of an impulse4 ,therefore1 the stops and the ends of the arms should be cut away 7backed off7 to rather a sharp angle to insure clearance when the arms are leaving the stops4 ,it is also of equal importance that the legs of the wheels should fall on the stops dead true4 ,the fit of each of the legs should be examined on both stops with a powerful eye-glass1 so that they should be correct and also see that when the unlocking takes place the wheel is absolutely free to turn4 ,,chapter ,,xii4 ,,the ,,cylinder ,,escapement ,,as ,,applied ,,to ,,clocks4 ,we remarked in a previous chapter that the lifting planes were sometimes on the wheel and sometimes on the anchor4 ,in another chapter we pointed out clearly that the run on the locking surface of the pallets had an important bearing on the freedom of the escapement and hence on the rate of the dead beat escapement4 ,in considering the cylinder escapement1 so common in carriage clocks1 we shall find that the lift is almost entirely on the curved planes of the escape wheel1 and that the locking planes are greatly extended1 so that they form the outer and inner surfaces of the cylinder walls4 ,thus we have here a form of the dead beat escapement1 which embraces but one tooth of the escape wheel and is adapted to operate a balance instead of a pendulum4 ,therefore the points for us to consider are as before1 the amount of lift1 lock1 drop and run1 and the shapes of our escape wheel teeth to secure the least friction1 as our locking surfaces 7the run7 being so greatly extended this matter becomes important4 ,,action ,,of ,,the ,,escapement4--,fig4 #eb is a plan of the cylinder escapement1 in which the point of a tooth of the escape wheel is pressing against the outside of the shell of the cylinder4 ,as the cylinder1 on which the balance is mounted1 is moved around in the direction of the arrow1 the wedge-shaped tooth of the escape wheel pushes into the cylinder1 thereby giving it impulse4 ,the tooth cannot escape at the other side of the cylinder1 for the shell of the cylinder at this point is rather more than half a circle2 but its point locks against the inner side of the shell and runs there till the balance completes its vibration and returns1 when the tooth which was inside the cylinder escapes1 giving an impulse as it does so1 and the point of the succeeding tooth is caught on the outside of the shell4 ,the teeth rise on stalks from the body of the escape wheel1 and the cylinder is cut away just below the acting part of the exit side1 leaving for support of the balance only one-fourth of a circle1 in order to allow as much vibration as possible4 ,this will be seen very plainly on examining ,fig4 #ec1 which is an elevation of the cylinder to an enlarged scale4 ,illustration3 ,fig4 #eb4 a1 wheel2 b1 cylinder2 f1 stalk on which teeth are mounted4 ,,proportion ,,of ,,the ,,escapement4--,the escape wheel has fifteen teeth1 formed to give impulse to the cylinder during from #bj to #dj of its vibration each way4 ,lower angles are as a rule used with large than with small-sized escapements2 but to secure the best result either extreme must be avoided4 ,in the escapement with very slight inclines to the wheel teeth1 the first part of the tooth does no work1 as the tooth drops on to the lip of the cylinder some distance up the plane4 ,on the other hand1 a very steep tooth is almost sure to set in action as the oil thickens4 ,the diameter of the cylinder1 its thickness and the length of the wheel teeth are all co-related4 ,the size of the cylinder with relation to the wheel also varies somewhat with the angle of impulse1 a very high angle requiring a slightly larger cylinder than a low one4 ,if a cylinder of average thickness is desired for an escapement with medium impulse1 its external diameter may be made equal to the extreme diameter of the escape wheel multiplied by #j4aae4 ,illustration3 ,fig4 #ec4 ,illustration3 ,fig4 #ed4 ,then to set out the escapement1 if a lift of say #cj be decided on1 a circle on which the points of the teeth will fall is drawn within one representing the extreme diameter of the escape wheel1 at a distance from it equal to #cj of the circumference of the cylinder4 ,midway between these two circles the cylinder is planted 7see ,fig4 #ed74 ,if the point of one tooth is shown resting on the cylinder1 a space of half a degree should be allowed for freedom between the opposite side of the cylinder and the heel of the next tooth4 ,from the heel of one tooth to the heel of the next equal #bd of the circumference of the wheel1 #cfj #ae #bd1 and from the point of one tooth to the point of the next also equals #bd so that the teeth may now be drawn4 ,they are extended within the innermost dotted circle to give them a little more strength1 and their tips are rounded a little1 having the points of the impulse planes on the inner or basing circle4 ,the backs of the teeth diverge from a radial line from #ab to #cj1 in order to give the cylinder clearance1 a high angled tooth requiring to be cut back more than a low one4 ,a curve whose radius is about two-thirds that of the wheel is suitable for rounding the impulse planes of the teeth4 ,the internal diameter of the cylinder should be such as to allow a little freedom for the tooth4 ,the rule in fitting cylinders is to have equal clearance inside and outside1 so as to equalize the drop4 ,the acting part of the shell of the cylinder 7where the lips are placed7 should be a trifle less than seven-twelfths of a whole circle1 with the entering and exit lips which are really the pallets1 rounded as shown in the enlarged plan1 ,fig4 #ee1 the entering lip or pallet rounded both ways and the exit pallet rounded from the inside only4 ,this rounding of the lips of the cylinder adds a little to the impulse beyond what would be given by the angle on the wheel teeth alone4 ,the diameter of the escape wheel is usually half that of the balance1 rather under than over4 ,,size ,,of ,,cylinder ,,pivot4--,to establish the size of the pivot with relation to its hole is apparently an easy thing to do correctly1 but to an inexperienced workman it is not so4 ,the side shake in cylinder pivot holes should be greater than that for ordinary train holes2 one-sixth is the amount prescribed by ,saunier2 the size of the pivot relatively to the cylinder about one-eighth the diameter of the body of the cylinder4 ,it is very necessary that this amount of side shake should be correctly recognized2 if less than the amount stated1 the escapement1 though performing well while the oil is fresh1 fails to do so when it commences to thicken4 ,illustration3 ,fig4 #ee4 ,when the balance spring is at rest1 the balance should have to be moved an equal amount each way before a tooth escapes4 ,by gently pressing against the fourth wheel with a peg this may be tried4 ,there is generally a dot on the balance and three dots on the plate to assist in estimating the amount of lift4 ,when the balance spring is at rest1 the dot on the balance should be opposite to the center dot on the plate4 ,the escapement will then be in beat1 that is1 provided the dots are properly placed1 which should be tested4 ,turn the balance from its point of rest till a tooth just drops1 and note the position of the dot on the balance with reference to one of the outer dots on the plate4 ,turn the balance in the opposite direction till a tooth drops again1 and if the dot on the balance is then in the same position with reference to the other outer dot1 the escapement will be in beat4 ,the two outer dots should mark the extent of the lifting1 and the dot on the balance would then be coincident with them as the teeth dropped when tried in this way2 but the dots may be a little too wide or too close1 and it will therefore be sufficient if the dot on the balance bears the same relative position to them as just explained2 but if it is found that the lift is unequal from the point of rest1 the balance spring collet must be shifted in the direction of the least lift till the lift is equal4 ,a new mark should then be made on the balance opposite to the central dot on the plate4 ,when the balance is at rest1 the banking pin in the balance should be opposite to the banking stud in the cock1 so as to give equal vibration on both sides4 ,this is important for the following reason4 ,the banking pin allows nearly a turn of vibration and the shell of the cylinder is but little over half a turn1 so that as the outside of the shell gets round towards the center of the escape wheel1 the point of a tooth may escape and jam the cylinder unless the vibration is pretty equally divided4 ,when the banking is properly adjusted1 bring the balance round till the banking pin is against the stud2 there should then be perceptible shake between the cylinder and the plane of the escape wheel4 ,try this with the banking pin1 first against one and then against the other side of the stud4 ,if there is no shake1 the wheel may be freed by taking a little off the edge of the passage of the cylinder where it fouls the wheel1 by means of a sapphire file1 or a larger banking pin may be substituted at the judgment of the operator4 ,see that the banking pin and stud are perfectly dry and clean before leaving them3 a sticky banking often stops a clock when nearly run down4 ,cylinder timepieces1 after going for a few months1 sometimes increase their vibration so much as to persistently bank4 ,to meet this fault a weaker mainspring may be used1 or a larger balance1 or a wheel with a smaller angle of impulse4 ,by far the quickest and best way is to very slightly lap the wheel by holding a piece of ,arkansas stone against the teeth1 afterwards polishing with boxwood and red stuff4 ,so little taken off the wheel in this way as to be hardly perceptible will have great effect4 ,sometimes the escape wheel has too much end shake4 ,we must notice in the first place how the teeth are acting in the cylinder slot4 ,suppose1 when the escape wheel is resting upon its bottom shoulder1 the cylinder will ride upon the plane of the wheel1 which will cause it to kick or give the wheel a trembling motion1 then we know that the cylinder is too low for the wheel2 therefore1 we have not only to lower the escape top cock in order to correct the end shake1 but we must also drive the bottom cylinder plug out a little in order to raise the cylinder sufficient to free it from the plane of the wheel4 ,now1 if the end shake of the cylinder is correct previous to this1 we shall now either have to raise the cock or drive the top plug in a little4 ,but suppose the end shake of the escape pinion is excessive1 and is1 when the bottom shoulder is resting on the jewel1 a little too low so that the bottom of the escape wheel runs foul of the cylinder shell2 in this case we simply drive out the steady pins from the bottom escape wheel cock and file a piece off the cock1 leaving it perfectly flat when we have enough off4 ,we then insert the steady pins again1 screw it down1 and if the end shake is right1 the escapement is mostly free and right also4 ,now let us consider the frictions2 there is the resistance of the pivots1 which depends on their radius1 on the weight of the balance1 the balance spring1 the collet1 and the weight of the cylinder2 these are called locking frictions4 ,then there are those of the planes1 of the teeth of the wheel1 of the lips of the cylinder4 ,it is on these that the change and destruction of the cylinder are produced4 ,to prevent this destruction1 it is necessary to render the working parts of the cylinder very hard and well polished1 as well as the teeth of the escape wheel4 ,the oil introduced in the cylinder is also a cause as in the dead beat4 ,it may thicken2 the dust proceeding from the impact of the escapement forms with the oil an amalgam which wears the cylinder4 ,the firmness and constancy of the cylinder depend on the preservation and fluidity of the oil4 ,then there are the accidental frictions2 the too close opening of the cylinder1 the play of the balance and of the wheel1 with the thickening of the oil1 changes the arc of vibration a good deal2 the teeth of the wheel may not be sufficiently hollowed1 so that the cylinder can revolve in the remaining space1 for the oil with the dust forms a thickness which also changes the vibration4 ,the drop should not be too great1 for it is increased by the thickening of the oil and impedes the vibration4 ,,examination ,,of ,,clocks4--,in this particular escapement1 when used for larger timepieces than watches1 it is astonishing the variety of methods which are employed1 yet the same results are expected4 ,in examining such clocks we will first notice that the chariot1 cock1 etc41 are so placed1 many of them1 that the last wheel in the train is a crown wheel1 hence it is made to work at #ij with the escape wheel pinion which is set at right angles with the crown wheel pinion1 and1 as a matter of course1 the cylinder is also set the same way4 ,now1 this arrangement needs especial care1 for it is quite natural that when the entire friction of the cylinder is only on the bottom part of the bottom pivot1 the clock is sure to go faster than when the whole length of both pivots are more in contact with their jewel holes1 which is always the case when the cylinder is parallel with all the pinions1 instead of standing upon one pivot only4 ,now1 although there must of necessity be a very great difference in timing the clock in the two different positions1 yet we find no difference in the strength of mainspring or any part of the train1 which is a mistake1 for the result is simply this3 the clock will gain time for the first few days after winding1 and will then gradually go slower and slower until the mainspring is entirely exhausted4 ,it is not very difficult to ascertain why it goes so fast after winding1 for then the whole tension of the spring is on1 and as there is not sufficient friction on the point of one pivot to counteract this1 the banking pin is almost sure to knock1 and will continue to knock for the first few days until a part of the spring's pressure is exhausted4 ,now1 in this case the knocking of the banking pin alone would cause the clock to gain time1 even if the extra tension of the mainspring did not assist it to do so4 ,hence1 on the whole1 the result is anything but satisfactory1 for such a clock can never be properly brought to time4 ,having said this much about the fault 7which is entirely through the want of a little forethought with the manufacturer71 ,i will give as good a remedy as ,i can suggest to give the reader an idea of how these faults may be put to right1 if he is willing to spend the time upon them4 ,in the first place take out the cylinder and make the bottom pivot perfectly flat instead of leaving it with a round end1 as they are mostly left1 which only allows just one part of the pivot to be in contact with the endstone4 ,by leaving this pivot flat on the bottom1 there is more surface in contact2 hence1 in a sense1 more friction4 ,in some cases the whole pivot left flat would not be sufficient to retard the mainspring's force2 then we must resort to other methods to effect a cure4 ,well1 our next method in order to try and get the clock to be a uniform timekeeper1 is to change the mainspring for one well finished and not quite so strong as the original one4 ,perhaps some will say 8why not do this before we go to the trouble of flattening the bottom pivot80 ,just this2 when a pivot is working only upon the bottom it is best to have a flat surface to work upon1 as the balance is then oscillated with more uniformity1 even when the mainspring is not exactly uniform in its pressure2 therefore we do no harm--but good--by making the bottom pivot flat1 and this alone will sometimes be sufficient to cure the fault of the banking knocking if nothing else4 ,to my mind1 when such strong mainsprings are used as we generally see in this class of timepiece1 neither of the jewel holes or pivots should be so small as they usually are4 ,fancy such small pivots as are mostly seen upon the escape wheel pinion being driven by such a strong mainspring4 ,if we allow the clock to run down while the escape wheel is in place1 we are very liable to find one or both pivots broken off before it gets run down4 ,i think all such pivots ought to be sufficiently strong to stand the pressure of the mainspring through the train of wheels without coming to grief4 ,but there is another reason why these pivots are liable to get broken off while letting the train run down3 that is1 the badly pitched depth we often find in the crown wheel and escape wheel pinion4 ,we frequently find too much end shake to the crown wheel which1 while resting one shoulder of the arbor against the plate puts the depth too deep1 and on the other shoulder the depth is too shallow4 ,now1 when the train is running rapidly this crown wheel is jumping about in the escape wheel pinion1 so that the roughness of the running all helps to break off the escape wheel pivots4 ,the best way to correct this depth is to notice how the screws fit in the cylinder plate--for these screws have to act as steady pins as well4 ,if the holes where the screws go through are at all large1 we then notice which would be the most convenient side to screw it securely in order to put a collet upon the shoulder of the crown wheel so that the depth will be right by making the end shake right with only fixing a collet to one shoulder4 ,this depth1 when correct1 will also cause a more uniform pressure upon the escapement1 and help to make the clock keep better time4 ,we are supposing that this crown wheel is perfectly true1 or it is not much use trying to correct the depth as mentioned above1 for even if the end shake be ever so exact and the wheel teeth are out of true1 we shall never get the depth to act as it ought1 neither can the clock be depended upon for keeping going1 regardless of keeping time4 ,when this crown wheel is out of true it is best to rivet it true1 not do as ,i have seen it done1 placed in the lathe and topped true1 and then the teeth rounded-up by hand4 ,this method simply means a faulty depth after all1 for in topping the teeth1 those teeth which require the most topping will1 when they are finished1 be shorter from the top to the base than those which do not get topped so much2 therefore1 some of the teeth are longer than the others1 while the shorter ones are thicker2 for when the wheel was originally cut the teeth were all cut alike4 ,these remarks will apply to several kinds of wheels2 for whenever a wheel is topped to put it true1 we may depend we are making a very faulty wheel of it unless we have a proper wheel cutting machine4 ,the crown wheel must not be too thick because we will find the tooth to act with the inner edge1 and what is left outside only endangers touching the pinion leaf which is next to come into action4 ,make sure the escape pinion is not too large1 which sometimes happens4 ,if it is1 it must be reduced in size1 or better1 put in a new one4 ,the crown wheel holes must fit nicely and the end shake be well adjusted4 ,do not spare any trouble in making this depth as perfect as you are able1 as most stoppages happen through the faults in this place4 ,it would be advisable1 when sure the depth is correct1 to drill two steady pin holes through the escapement plateau into the edge of the plates4 ,when steady pins are inserted this will always ensure the depth being right when put together4 ,in some of these clocks it is not only the crown wheel1 but frequently the escape wheel has too much end shake4 ,the former1 as ,i have said1 can be corrected by making a small collet that will just fit over pivot1 fasten it on friction-tight1 place the wheel in the lathe and turn the collet down until it is the same size as the other part of the arbor1 then run off the end to the exact place for the end shake to be right4 ,if it is properly done and a steel collet is used1 it will not be detected that a collet has been put on4 ,now1 when the escape wheel end shake is wrong we have to proceed differently under different circumstances for we must notice in the first place how the teeth are acting in the cylinder slot4 ,see that the cylinder and wheel are perfectly upright4 ,suppose1 when the escape wheel is resting upon its bottom shoulder1 the cylinder will ride upon the plane of the wheel1 which will cause it to kick or give the wheel a trembling motion1 then we know that the cylinder is too low for the wheel2 therefore1 we have not only to lower the escape top cock in order to correct the end shake1 but we must also drive the bottom cylinder plug out a little in order to raise the cylinder sufficient to free it from the plane of the wheel4 ,now1 if the end shake of the cylinder is correct previous to this1 we shall either have to raise the cock or drive the top plug in a little4 ,but suppose the end shake of the escape pinion is excessive1 and is1 when the bottom shoulder is resting on the jewel1 a little too low so that the bottom of the escape wheel runs foul of the cylinder shell2 in this case we simply drive out the steady pins from bottom escape wheel cock and file a piece off the cock1 leaving it perfectly flat when we have got enough off4 ,we then insert the steady pins again1 screw it down1 and1 if the end shake is right1 the escapement is mostly free and right also4 ,it sometimes happens that the wheel is free of neither the top nor bottom plug1 but should this be the case1 sufficient clearance may be obtained by deepening the opening with a steel polisher and oilstone dust or with a sapphire file4 ,a cylinder with too high an opening is bad1 for the oil is drawn away from the teeth by the escape wheel4 ,if a cylinder pivot is bent1 it may very readily be straightened by placing a bushing of a proper size over it4 ,these clocks are very good for the novice to exercise his skill in order to thoroughly understand the workings of the horizontal escapement4 ,he is better able to see how the different parts act with each other than he is in the small watch4 ,when the escape is correct he will find that the plane of the escape wheel will work just in the center of the small slot in the cylinder4 ,if he will notice how the teeth stand in the cylinder when the banking pin is held firmly upon the fixed banking pin1 it will give him an idea of how this should be4 ,at one side the lip of the cylinder is just about to touch the inside of the escape tooth1 but the banking pin just prevents it from doing so1 while on the other side the cylinder goes round just far enough to let the point of the next tooth just get on the edge of the slot1 but it cannot get in owing to the intervention of the banking pin4 ,if this is allowed to get in the slot just here1 we then have what is called 8a locking10 which is1 in reality1 an overturned banking4 ,if the other side is so that the banking pin does not stop it soon enough1 the edge of the slot knocks upon the inside of the teeth and causes a trembling of the escape wheel1 and the clock left in this form will never keep very good time4 ,we may easily remedy this by taking off the hair spring collet2 holding the cylinder firmly in the plyers1 and with the left hand turn the balance a little outwards2 this will bring the banking pins in contact before the cylinder touches the inside of the wheel teeth1 and all is right1 providing we are careful in not doing it too much2 if so1 we shall find the banking knock--a fault which is quite as bad1 if not worse1 than the one we are trying to remedy4 ,those particulars are the most important of anything in connection with the cylinder escapement4 ,yet1 as this kind of clock is now being made up at such a low price1 these seeming little items are frequently overlooked2 hence1 when they get into the hands of the inexperienced1 there is often more trouble with them than there need be if they knew where to look for some of the faults which ,i have been endeavoring to bring to light4 ,there are several other things in connection with this particular clock1 but we will not comment further just now1 but take them up when we are considering the trains1 etc4 ,illustration3 ,fig4 #ef4 ,in the meantime we will resume our study of the cylinder escapement with particular reference to badly worn or otherwise ill fitting escape wheels1 as many times1 the other points being right1 the wheel and cylinder may be such as to give either too great or too small a balance vibration4 ,a poor motion can also be due to a rough or a badly polished cylinder1 but such a cylinder we rarely find4 ,that with a wrong shape of the cylinder lips the motion is not much lessened can be seen in quite ordinary movements1 where the quality is certainly not of the best neither are the lips correctly formed1 nevertheless they have rather an excessive motion4 ,to cover up these defects in such movements the cylinder wheel teeth are purposely given the shape as shown at ,b in ,fig4 #ef1 and to give sufficient power a strong mainspring is inserted4 ,with an excessive balance vibration we can usually conclude that it is an intentional deception on the part of the manufacturer1 while a poor motion can generally be ascribed to careless methods in making4 ,the continued efforts in making improvements to quicken and cheapen manufacturing processes very frequently result in the introduction of defects which are only found by the experienced and practical watchmaker4 ,as to the causes which induce excessive balance vibrations8 ,as this defect is generally found in the cheaper grades of cylinder escapements1 having usually rather small1 heavy1 and often clumsy balances1 those which have balances whose weight is probably less than they ought to be1 need not here be further considered1 and it only remains for us to look to the cylinder or the escape wheel for the causes which produce these excessive vibrations4 ,it will be found that the cylinder is smaller in diameter than usually employed in such a size of clock2 the escape wheel is naturally also smaller1 and its teeth generally resemble ,b1 ,fig4 #ef1 while ,a shows the correct shape of a tooth for a wheel of that diameter4 ,in using small cylinders we can give the escape wheel teeth a somewhat greater angle of inclination than generally used1 but that the proper amount of incline is exceeded is proved by the fact that the balance vibrates more than two-thirds of a turn4 ,it can also be readily seen that with a tooth like ,b a greater impulse must be imparted than one with an easy curve like ,a1 and the impulse is still further increased as the working width of the tooth ,b 7the lift7 is greater1 indicated by line b1 while the same line in a correct width of tooth1 as shown at a1 is considerably shorter4 ,in addition to what has been said of these escapements1 we also find them provided with very strong mainsprings to give the necessary power to a tooth like ,b with its steeply inclined lifting face or impulse angle4 ,to decrease the great amplitude of the balance vibrations many watchmakers simply replace the strong mainspring with a weaker one4 ,but this procedure is not advantageous as the power of the escape wheel tooth is insufficient to start the balance going and this is due to two causes4 ,first1 the great angle of the escape wheel tooth1 and secondly1 the inertia of the balance4 ,it is only by violently shaking such a clock that1 we are enabled to start it going4 ,and the owner soon becomes dissatisfied from its frequent stoppage due to setting of the hands and other causes so that he will be often obliged to shake it until it starts going once more4 ,illustration3 ,fig4 #eg4 ,fig4 #eh4 ,for properly correcting these defects the best method to pursue is to replace the cylinder wheel with another one1 whose teeth are of the shape as shown at ,fig4 #ee and without question a good workman will always replace the escape wheel if the clock is of fair quality4 ,but if a low grade one1 we would hardly be justified in going to the expense of putting in new wheels1 as the low prices for which these clocks are sold preclude such an alteration4 ,as we must improve the wheel some way to get a fair escapement action we can place it in a lathe and while turning1 hold an oil stone slip against it1 we can remove the point ,s1 ,fig4 #ef4 ,after removing the point the tooth will now have the form as shown at tooth ,c1 ,fig4 #eg4 ,we now take a thin and rather broad watch mainspring1 bending a part straight and holding it in the line f f1 and revolving the wheel in the direction as shown by the arrow1 its action being indicated by figures #a to #h2 beginning at the point of the tooth at #a1 at #b it comes in contact with the whole of the lifting face1 and from #c to #h only on the projecting corner which was left by the oil stone slip in removing the heel of the tooth4 ,in this way all the teeth are acted upon until the corner is entirely removed4 ,of course oil stone dust and oil is first used upon the spring for grinding1 after which the teeth are polished with diamantine4 ,care must be observed in using the spring so as not to get the end f too far into the tooth circle1 as it would catch on the heel of the preceding tooth4 ,after the foregoing operation has been completed any feather edge remaining on the points of the teeth must be removed with a sapphire file and polished2 we will now have a tooth as indicated by ,d1 ,fig4 #eg4 ,this shape of tooth can hardly be said to be theoretically correct1 nevertheless it is a close approximation of the proper form of tooth1 which is shown by the dotted lines1 and will then perform its functions much better than in its original condition4 ,fig4 #eh also shows how the spring must be moved from side to side--indicated by dotted lines--so that the lifting face will have a gentle curve instead of being flat2 ,r represents the tooth4 ,after the wheel has been finished1 as described1 and again placed in the clock1 it will be found that the balance makes only two-thirds of a turn1 and as a result the movement can be easier brought to time and closely regulated4 ,in the above ,i have described the cause of excessive balance vibration1 the method by which it can be corrected1 and in what follows ,i shall endeavor to make clear the reasons for a diminished balance vibration or poor motion4 ,it has been probably the experience of most watchmakers to repair small cylinders of a low grade1 having a poor motion or no motion at all1 and it would hardly be profitable to expend much time in repairing them4 ,but considerable time is often wasted in improving the motion by polishing pivots and escape wheel teeth1 possibly replacing the cap jewels1 or even the hole jewels1 increasing the escapement depth or making it shallower1 examining the cylinder and finding nothing defective1 and as a last effort putting in a stronger mainspring4 ,but all in vain1 the balance seems tired and with a slight pressure upon an arm of the center wheel it stops entirely4 ,illustration3 ,fig4 #ei4 ,in this case1 as in a former one1 in fact1 it is necessary at all times to carefully examine the cylinder wheel4 ,my reason for not considering the cylinder itself so much as the wheel is that the makers of them have made a considerable advance in their methods of manufacture1 so we find the cylinders fairly well made and generally of the correct size4 ,even if the cylinder is incorrectly sized1 either too large or small1 it does not necessarily follow that the watch would have a bad motion1 as ,i have frequently had old movements where the cylinder was incorrectly proportioned and yet the motion was often a good1 satisfactory one4 ,generally speaking1 the cylinder escapement is one which admits of the worst possible constructive proportions and treatment1 as we have often examined such clocks when left for repairs1 that1 notwithstanding their being full of dirt1 worn cylinder1 broken jewel holes1 etc41 they have been running until one of the cylinder pivots has been completely worn away4 ,it only remains to look for the source of the trouble in the escape wheel4 ,if we examine the wheel teeth carefully1 we shall find them resembling those in ,fig4 #ei1 the dotted lines representing the correct shape of the teeth for a wheel of that diameter4 ,why do we find wheels having such defective teeth8 ,this is probably due to their rapid manufacture1 as they very likely had the correct shape when first cut1 but by careless grinding and polishing they were given improper forms1 careless treatment being very evident at tooth ,f1 which we find on examination has a feather edge at the point as well as at the heel of the tooth4 ,if we grind these edges of the tooth with a ruby file1 by placing it in the position as indicated by dotted lines h and h1 and afterwards polishing the tooth point1 we will find that the balance makes a better vibration4 ,a wheel1 having teeth like ,e1 can still be used1 but the balance will have a very poor motion1 due to the fact that the impulse angle of the wheel tooth is too small2 the impulse faces of the teeth having so small an angle1 are nearly incapable of any action4 ,with a tooth like ,g1 if we should remove its bent point at the dotted line d1 then the tooth would be too short1 and as the inclination of the impulse face is incapable to produce a proper action1 a new wheel must be used1 having teeth as shown at ,fig4 #ee4 ,the reasons why a tooth1 having the shape as shown at ,f and ,g 7,fig4 #ei71 will cause a bad action of the escapement and also why in such cases with a greater force acting on the wheel1 causes a stopping of the clock1 ,i will endeavor to explain with the aid of the illustration ,fig4 #fj4 ,here we clearly see the curved points of the teeth resting against the outer and inner walls of the cylinder while the escapement is in action4 ,teeth ,h and ,h represent the defective tooth1 while ,k and ,k shows a correctly formed tooth for a wheel of the same size1 the correct depth and positions where the tooth strikes the inner and outer walls of the cylinder4 ,it will be readily seen that the position of the tooth point upon the cylinder 7at c7 is most favorable in reducing the resistance to the least possible amount4 ,but in the case of the teeth ,h and ,h the condition is entirely different4 ,we find that it was necessary to set the escapement very deeply in order that it could perform its functions at all1 and1 as a consequence1 we have a false proportion2 the effects being considerably increased by the worst possible position of the teeth ,h and ,h1 where they touch the cylinder4 ,while the cylinder c is turning in the direction shown by the arrows i i1 the tooth does not affect the cylinder to any extent2 but during the reverse movement of the cylinder1 in the direction of o o1 an excessive amount of engaging friction must take place4 ,a close inspection of the drawing will enable us to see that there is a great tendency of the cylinder to drag the tooth along with it during each of these motions4 ,it is evident that in such a case the friction will eventually become so great as to lock the escapement1 and if greater pressure is applied by any means to teeth ,h and ,h1 it is easily seen that this effect will take place much more rapidly4 ,replacing the escape wheel with one of correctly formed teeth and size is the best means at our disposal4 ,illustration3 ,fig4 #fj4 ,,chapter ,,xiii4 ,,the ,,detached ,,lever ,,escapement ,,as ,,applied ,,to ,,clocks4 ,as the clock repairer is almost of necessity a watchmaker1 or hopes to become one1 and as he must enter deeply into the study of all questions pertaining to the detached lever in its various forms before he can make any progress at all in watchmaking1 it would seem unnecessary to repeat in these pages that which has already been so well said and so perfectly drawn1 described and illustrated by such authorities as ,moritz ,grossman1 ,britten1 ,playtner and the various teachers in the horological schools1 to say nothing of an equally brilliant and more numerous coterie of writers among the ,french1 ,germans and ,swiss1 so that the reader is referred to these writers for the mathematics and drawings which already so fully cover the technical and theoretical properties of the detached lever escapement4 ,a few words as to its adaptation to clocks may1 however1 not be out of place4 ,anyone who sees the clocks of to-day would be inclined to suppose that the first clocks were constructed with pendulums1 because this is evidently the most simple and reliable system for clocks1 and that the employment of the balance has been suggested by the necessity for portable time pieces4 ,this is1 however1 not the case1 for the first clocks had a verge escapement with a crude balance consisting of two arms1 carrying shifting weights for regulation4 ,the pendulum was not used until about three hundred years after the invention of the first clock4 ,after the invention of the dead beat escapement1 with its great gain in accuracy by the reduction of the arc of pendulum oscillation1 attempts were made to combine its many virtues with the necessarily large vibrations of a balance and thus get all the advantages of both systems4 ,by placing the lever on the arbor of the anchor1 it was possible to multiply the small angle of impulse on the pallets very considerably at the balance1 and to make all connection between them cease immediately after the impulse had been given4 ,the dead beat escapement was thus converted into the detached lever escapement and the latter made available for both watches and clocks4 ,another important feature of this escapement is that when properly proportioned it will not set on the locking or lifting1 but will start to go as soon as power is applied to the escape wheel through the train4 ,this cannot be said of the cylinder1 duplex1 or detent escapements1 and it will be seen at once that this has an important influence upon the cost of construction1 which must always be considered in the manufacture of cheap clocks in enormous quantities4 ,illustration3 ,fig4 #fa4 ,pin ,escapement for ,clocks4 ,the lever escapement with pins for pallets and the lifting planes on the teeth of the escape wheel1 which is the one usually put into cheap clocks1 is from the theoretical point of view a very perfect form1 because its lifting and locking take place at exactly the same center distance and at the same angles1 which again allows for greater latitude in cheap construction1 while still maintaining a reasonably accurate rate of performance4 ,these are the main reasons why the pin anchor has such universal use in cheap clocks4 ,as this escapement is generally centered between the plates1 banking pins are dispensed with by extending the counterpoise end of the lever far enough so that its crescent shaped sides will perform that office by banking against the scape wheel arbor2 see ,fig4 #fa4 ,the fork end of the lever engages with an impulse pin carried in the balance and the balance arbor is cut away to pass the guard point or dart1 thus doing away with the roller table4 ,in other constructions the roller table is supplied in the shape of a small brass collet which carries the pin and has a notch for the guard point1 thus making a single roller escapement4 ,the diameter of the lifting pins is generally made equal to #b degrees of the scape wheel1 which gives a lift of #b degrees on the pallet arms1 and the remainder of the lift1 #f degrees1 must be performed by the lifting planes of the wheel teeth4 ,the front sides of the wheel teeth are generally made with #ae degrees of draw and the lever should bank when the center of the pin is just a little past the locking corner of the tooth4 ,other details of the pin anchor escapement coincide with the ordinary pallet form1 as used in watches1 and the reader is referred for them to the works of the various authors mentioned previously4 ,the trouble with the majority of these clocks is in the escapement and balance pivots1 and to these parts are we going to direct particular attention1 for often1 be it ever so clean1 the balance gets up a sort of 8caterpillar motion0 that is truly distressing1 and if no more is done we may expect a 8come back0 job in a very short time4 ,in taking down the movement the face wheels are left in place1 but sometimes it may be necessary to remove the 8set wheel0 of the alarm in order to proceed as we do4 ,remove the screws or pins that hold the plates together in the vicinity of the escapement1 leaving the others1 though if screws they may be loosened slightly2 pry up the corner of the plate over the lever to loosen one pivot of same and let it drop away from the scape wheel sufficiently to let the wheel revolve until it is locked by a wire or pegwood previously inserted in the train1 after which the plates can be pried apart more conveniently to permit the lever being removed entirely1 also the scape wheel and the one next following4 ,as nickel clocks differ in make-up1 the operator must1 of course1 exercise judgment as to the work in hand to accomplish this4 ,have ready a straight-sided tin pail1 with cover1 that will hold at least one-half gallon of gasoline and of diameter large enough to receive the largest brass clock2 remove the wire or pegwood and immerse the clock into the fluid and allow it to run down2 this will loosen all the dirt and gummy oil and clean the clock very effectually4 ,let it remain long enough for all the dirt to settle to the bottom of the pail2 then remove and wipe as dry as possible with a soft rag2 by having no binder on the spring it is permitted to uncoil to its full1 and thereby remove all gummy oil between its coils4 ,now peg out the holes of the wheels removed and of the lever and that portion of our work is complete4 ,polish or burnish the pivots of wheels either in a split chuck in the lathe1 or by holding in a pin vise1 resting the pivot on a filing block 7an ivory one is best71 and revolving between the fingers1 using a smooth back file for burnishing1 after the manner of pointing up a pin tongue1 only let the file be held flat1 so as to maintain a cylindrical pivot as nearly as possible4 ,the scape wheel is now polished1 i4 e41 the teeth1 with a revolving bristle wheel on a polishing lathe1 charged with kerosene oil and tripoli4 ,this will smooth up the teeth in fine form1 especially those wheels that work into a lever with pin pallets4 ,clean the scape wheel by dipping into gasoline to remove all the oil and tripoli4 ,the other wheel may simply be brushed in the gasoline or dipped and then brushed dry4 ,we now turn our attention to the lever and closely examine the pallets with a glass2 if there are the least signs of wear upon them they must be removed4 ,of the lever with pin pallets it is better to remove the steel pins and insert new ones4 ,see if the holes in the anchor where they are inserted will admit a punch to drive them out from the back2 if not1 open these holes with a drill until the ends of the pins are reached4 ,put a hollow stump with a sufficiently large hole in the staking tool1 and by placing the pins in the stump they can be driven out successively1 being sure that the driving punch is no larger than the pins2 drive or insert into their places a couple of needles of the proper size1 and then break off at correct lengths2 this completes the job in this particular style of lever4 ,with the other style the job is not quite so easy2 with a pair of small round-nose pliers grasp the brass fork close up to the staff and bend it back from the pallets till it lays parallel with the staff2 treat the counter poise of the fork in like manner2 place a thin zinc lap into the lathe1 charged with flour of emery1 and with the fingers holding the pallets grind off all wheel teeth marks on both the impulse and locking faces of the pallets4 ,then polish with a boxwood lap charged with diamantine4 ,it is surprising how speedily this can be done if laps are at hand4 ,the only care necessary is not to round off the corners of the pallets1 and as they are so large they can be easily held flat against the laps with the thumb and finger as before stated4 ,bend back the fork and counterpoise to their original position4 ,the fork must now be attended to2 see that no notches are worn in the horns of the fork by the steel impulse pin in the balance2 if they appear they must be dressed out and polished1 also examine and smooth if necessary the ends of the horns that bank against the balance staff4 ,these may seem small matters1 but they are often what cause all the trouble4 ,we now come to the balance staff and the hardened screws in which the staff vibrates2 their irregularities are often the source of much vexation1 and there is only one way to go at it and that is with a will and determination to make it right4 ,examine the points of the staff and see if they are in their normal shapes and are sharp and bright2 if so they will probably do their work4 ,but we will suppose we have a bad case in hand and will therefore treat it thoroughly according to our method4 ,we find the staff is large in diameter and the ends are very blunt2 the notch in the center has a burr on each side as hard as glass1 making an admirable cause for catching the horns of the fork in some of the vibrations or in a certain position2 also the round part of the staff back of the notch is rough and looks as if it never had been finished1 and1 in fact1 it has not1 for it truly appears as if half1 if not all1 the nickel clocks are made to be finished by the watchmaker4 ,remove the hairspring and place the staff between the jaws of your bench vise1 with the jaws close up to the staff1 but not gripping it1 the balance 8hub0 resting on the jaws with the impulse pin also down between the jaws4 ,have a block of brass about one-fourth inch square2 rest it on top of the staff1 or on its pivot end1 if it may so be called1 holding it with the thumb and finger of the left hand4 ,strike this block with a hammer and drive out the staff2 a hollow punch is apt to be split in doing this1 and as the pivot is to be re-pointed no harm will be done to the pivot or to the end of the staff4 ,draw the temper so it will work easily1 insert into a split chuck and turn up new points2 have them long and tapering1 that is1 turn the points to a long slant from the end of the staff to the body of same1 or at least twice as much taper as they generally have2 polish off the back of the notch or round part of the staff with an oil stone slip4 ,remove from the chuck1 smear all over with powdered boracic acid by first wetting the staff in water1 and then heat to a bright red and plunge straight into water2 it will now be white and hard2 draw the temper from the staff in the vicinity of the notch1 leaving the pivot points hard as before2 re-insert into the chuck and with diamantine polish the points and also around the staff in the vicinity of the notch4 ,the drawing of the temper from the center of the staff to a spring temper is to make it less liable to breakage while driving on the balance4 ,fasten the staff tight in the vise and with a rather stout brass tube1 large enough to step over the largest staff1 drive on the balance to its former position4 ,if the workman has a pivot polisher with a large lap1 the job may be done1 without softening the staff or removing the balance1 by grinding the pivots4 ,in turning the staff we often find it almost impossible to hold true4 ,we straighten the best we can and then turn up our pivots1 and as long as the untruth of the staff will not cause the balance to wabble to such an extent as to give us a headache or cause us to look cross-eyed it will do4 ,we do not wish to be misunderstood or to give the impression that we go on the principle of 8good enough02 but as gold dollars cannot be bought for seventy-five cents1 neither can a workman devote the time to have everything perfect for fifty cents2 and for this very reason do they come in such an unfinished state from the manufacturers4 ,next see if the two screws in which the balance vibrates have properly cut countersinks2 if rough or irregular1 better at once draw the temper1 re-drill with a sharp-angled drill and again harden4 ,occasionally a bunch of these clocks will come in with both pivots and cones badly rusted4 ,this has generally been caused by acid pickling1 or some sort of chemical hardening at the factory2 the acid or alkali gets into the pores of the steel and comes out after the clock has been shipped4 ,they are generally made in such quantities that fifty or a hundred thousand of them have been distributed before finding out that they were not right and then it is a matter of two or three years before the factory hears the last of it4 ,the trouble is attributed to bad oil1 or to anything else but the hardening1 which is the real cause1 and the expense of taking back and refitting the balance arbors and cones1 paying freight both ways and standing the abuse of disgruntled jewelers1 goes on until life becomes anything but a bed of roses4 ,every jeweler should warn the factory immediately on finding rust in the cones of a shipment of new clocks and not attempt to fix them himself1 as such a fault cannot be discovered at the factory and every day it continues means more thousands of clocks distributed that will give trouble4 ,our clock is now ready to be put together4 ,wind up the spring and slip on the binder2 then put in the wheels and lever2 then adjust the balance and hairspring to their proper places1 slightly wind the mainspring and then see 7by bringing either horn against the staff7 whether it sticks and holds the balance2 if so1 shorten the fork slightly by bending2 try this until the balance and fork act perfectly free and safe4 ,slightly oil the balance pivots2 an excess will only gather dust and prove detrimental1 as the countersinks form an admirable place for holding the dust4 ,now oil the remaining parts and we are sadly mistaken if our clock does not make a motion that will be gratifying4 ,the foregoing process may seem tedious and uncalled for and too close mention made of the lesser portions of the work1 but we must not 8despise the day of small things10 and as we are watchmakers1 we are expected to do this work1 even though troublesome and the pay small2 we should also bear in mind that if we only make a nickel clock run and keep fair time1 it will be a large advertisement1 and possibly repay tenfold4 ,it takes only an hour to do this job complete1 while in many cases only the balance staff needs attention4 ,sometimes such a clock will be apparently all right mechanically but will continue to lose time2 then it is probable that the balance does not make the proper number of vibrations1 which causes the clock to lose time4 ,there is one way to tell this1 which will soon locate the trouble3 count the train to ascertain the number of vibrations the balance should make in one minute4 ,you do this by counting the number of teeth in the center wheel1 which we will say is #dh2 third wheel #dh2 fourth wheel1 #de2 escape1 #ae4 ,multiply all teeth together1 which give us #dh #dh #de #ae #a1eee1bjj4 ,now count the leaves in the third wheel pinion1 which is #f2 fourth1 #f2 escape1 #f4 ,multiply these together1 #f #f #f #baf2 now divide the leaves into the teeth1 #a1eee1bjj #baf #g1bjj1 which is the number of whole vibrations some ,ansonia alarm clocks make in one hour4 ,dividing #g1bjj by #fj gives us #abj1 the number of vibrations per minute4 ,now the balance must make #abj vibrations in one minute1 counting the balance going one way4 ,if the balance only vibrates #aah1 the clock will lose time and the hairspring must be taken up or made shorter1 until it makes the required number of vibrations4 ,if it should vibrate #abb the clock would gain and the hairspring should be let out4 ,find out the number of vibrations your balance should make and work accordingly2 and if you find that the balance makes the proper number of vibrations in one minute1 then the trouble must lie in the center post1 which has not enough friction to carry the hands and dial wheels1 or the wheel that gears into the hour wheel and regulates the alarm hand is too tight and holds back the hands4 ,you should find some trouble about these wheels or center post1 for where a balance makes the proper number of vibrations in one minute1 the minute hand cannot help going around if everything else is correct4 ,fig4 #fb illustrates the escapement of the ,western ,clock ,manufacturing ,company for their cheap levers4 ,it has hardened steel pallets placed in a mould and the fork cast around them1 thus insuring exact placing of the pallets1 and the company claim that they thus secure a detached lever escapement with all the advantages of hardened and polished pallets at a minimum cost4 ,illustration3 ,fig4 #fb4 ,mr4 ,f4 ,dauphin1 of ,cassel1 ,germany1 on page #chg of ,der ,deutsche ,uhrmacher ,zeitung1 #aije1 has described a serious fault of some of the cheap ,american alarm clocks in the depthings of the escapements and how he remedied it by changing the position of the pins4 ,it is to be regretted that ,mr4 ,dauphin did not state the measurements of the parts as nearly as possible in this article and also give the manufacturer's name1 simply to enable others not as skilled as he is to do what ,i would do in such a case2 namely1 to return it to the jobber and get a new and correct movement in its stead free of charge4 ,the ,american clock manufacturers are very liberal in this respect and never hesitate to take back a movement that was not correct when it left the factory1 even when the customer1 in the attempt to correct it1 has spoiled it2 spoiled or not1 it goes to the waste pile anyway1 when it reaches the factory4 ,i seriously doubt the ability of the average watch repairer to correctly change the position of the pins as suggested2 and to change the center of action of the lever is certainly a desperate job4 ,i herewith give a correct drawing of an escape wheel and lever1 such as are used in the above cited clocks1 made from measurements of the parts of a clock4 ,the drawing is1 of course1 enlarged4 ,the measurements are3 ,escape wheel1 actual diameter1 #ah4aa mm42 original diameter1 #ag mm42 lever1 from pin to pin1 outside1 #i4c mm42 distance of centers of wheel and lever1 #aj4j mm4 ,i found that all these measurements almost exactly agree with ,grossmann's tables1 and ,i do not doubt at all that they were taken from them4 ,there is only one mistake visible1 which is in the shape of the escape teeth1 and ,i fail to see why this was overlooked by those in charge at the factory2 the draw is insufficient4 ,it is only from seven to eight degrees1 when it should be fifteen degrees4 ,i show this at tooth ,a1 in the drawing1 where you can see both dotted lines1 measuring the angle of draw2 line ,c as it is and line ,b as it should be4 ,illustration3 ,fig4 #fc4 ,notwithstanding the deficient draw1 this escapement will work safely as long as the pivot holes are not too large1 or worn sideways2 but if you want to make it safe you should file the locking faces of teeth slightly under2 even if you do not make a model job1 you have remedied the fault4 ,make a disk of #ah4aa mm4 diameter1 put it on the arbor of the wheel and lay a straight edge from the point of the tooth to the center of the disk1 so as to see how much it needs to be filed away4 ,even if this undercutting is not very true it will go4 ,,to ,,measure ,,wheels ,,with ,,odd ,,numbers ,,of ,,teeth4--,this is a job that so frequently comes to the watchmaker who has to replace wheels or pinions that the following simple method should be generally appreciated4 ,it depends upon the fact that the radius of a circle1 ,r1 ,fig4 #fd1 equals the versed sine ,e 7dotted7 plus the cosine ,b4 ,if we stand such a wheel on the points of the teeth1 ,a ,c1 and measure it we shall get the length of the line ,t ,b only1 when what we really need is the length of the lines ,t ,b ,e1 to give us the real diameter for our wheel1 and ,e we find has been cut away1 so that we cannot measure it4 ,say it is a #ae-tooth escape wheel1 then by standing the old wheel up on the anvil of a vertical micrometer1 resting it on two of its teeth1 as shown in ,fig4 #fd1 the measuring screw can be brought in contact with the tooth diametrically opposite the space between the two teeth on the anvil1 and a measurement taken1 which will be less than the full diameter by the versed sine of #ab degrees 7half the angle included between two adjoining teeth74 ,by bringing each tooth in succession to the top1 such a wheel could be measured in fifteen different directions1 which would vary slightly1 owing to the fact that some of the teeth may be bent a little1 but the mean of these measures should be what the wheel would measure were the teeth in their original shape4 ,if a tooth was badly bent the three measures in which it was involved could be rejected1 and the mean of the other twelve measures taken as the correct value and found to be1 we will say1 #j4gcb inch4 ,consulting a table of natural sines the cosine of #ab degrees is found to be #j4ighae1 which subtracted from #a gives #j4jbahe as the versed sine4 ,multiplying this by #j4cf inch 7practically one-half of our measured #j4gcb7 to get the approximate radius of the wheel1 we get #j4jjh inch1 the amount to be added to the micrometer measurement in order to get the diameter of the blank4 ,at first sight it may appear like a vicious principle that we must know the radius of the wheel before we can determine the value of the correction in question1 but we only need to know the radius approximately in order to determine the correction very closely1 an error of _/ inch in the assumed value of the radius producing an error of only #j4jja inch in the value of the correction4 ,illustration3 ,fig4 #fd4 ,getting the full diameter4 ,this method can of course be applied to all wheels and pinions to get the size of the blank2 with other wheels than escape wheels1 where the pitch line and the full diameter do not coincide1 the addendum may be subtracted from the full diameter to get the pitch line4 ,,cutters ,,for ,,clock ,,trains4--,in cutting escape wheels or others with wide space between the teeth1 it is a matter of some difficulty with many people to enable them to set the cutter properly4 ,mr4 ,e4 ,a4 ,sweet calls attention to the fact that if a cutter be set so that its center touches the circumference of the wheel to be cut1 said cutter will be in the proper position for work4 ,for instance1 if an escape wheel is to be cut1 it is sufficient to set the cutter in such a manner that that portion of the cutter forming the bottom of the cut touch the circumference of the blank at the center of the cutter4 ,it may then be backed off and fed in with the certainty of being properly placed4 ,,chapter ,,xiv4 ,,plates1 ,,pivots ,,and ,,time ,,trains4 ,before going further with the mechanism of our clocks we will now consider the means by which the various members are held in their positions1 namely1 the plates4 ,like most other parts of the clock these have undergone various changes4 ,they have been made of wood1 iron and brass and have varied in shapes and sizes so much that a great deal may be told concerning the age of a clock by examining the plates4 ,most of the wooden clocks had wooden plates4 ,the ,english and ,american movements were simply boards of oak1 maple or pear with the holes drilled and bushed with brass tubes--full plates4 ,the ,schwarzwald movements were generally made with top and bottom boards and stanchions1 mortised in between them to carry the trains1 which were always straight-line trains4 ,the rear stanchions were glued in position and the front ones fitted friction-tight1 so that they could be removed in taking down the clock4 ,this gave a certain convenience in repairing1 as1 for instance1 the center 7time7 train could be taken down without disturbing the hour or quarter trains1 or vice versa4 ,various attempts have been made since to retain their convenience with brass plates1 but it has always added so much to the cost of manufacture that it had to be abandoned4 ,the older plates were cast1 smoothed and then hammered to compact the metal4 ,the modern plate is rolled much harder and stiffer and it may consequently be much thinner than was formerly necessary4 ,the proper thickness of a plate depends entirely upon its use4 ,where the movement rests upon a seat board in the case and carries the weight of a heavy pendulum attached to one of the plates they must be made stiff enough to furnish a rigid support for the pendulum1 and we find them thick1 heavy and with large pillars1 well supported at the corners1 so as to be very stiff and solid4 ,an example of this may be seen in that class of regulators which carry the pendulum on the movement4 ,where the pendulum is light the plates may therefore be thin1 as the only other reason necessary for thickness is that they may provide a proper length of bearing for the pivots1 plus the necessary countersinking to retain the oil4 ,in heavy machinery it is unusual to provide a length of box or journal bearing of more than three times the diameter of the journal4 ,in most cases a length of twice the diameter is more than sufficient2 in clock and other light work a 8square0 bearing is enough2 that is one in which the length is equal to the diameter4 ,in clocks the pivots are of various sizes and so an average must be found4 ,this is accomplished by using a plate thick enough to furnish a proper bearing for the larger pivots and countersinking the pivot holes for the smaller pivots until a square bearing is obtained4 ,this countersinking is shaped in such a manner as to retain the oil and as more of it is done on the smaller and faster moving pivots1 where there is the greatest need of lubrication1 the arrangement works out very nicely1 and it will be seen that with all the lighter clocks very thin plates may be employed while still retaining a proper length of bearing in the pivot holes4 ,the side shake for pivots should be from 4#jjb to 4#jjd of an inch2 the latter figure is seldom exceeded except in cuckoos and other clocks having exposed weights and pendulums4 ,here much greater freedom is necessary as the movement is exposed to dust which enters freely at the holes for pendulum and weight chains1 so that such a clock would stop if given the ordinary amount of side shake4 ,we are afraid that many manufacturers of the ordinary ,american clock aim to use as thin brass as possible for plates without paying too much attention to the length of bearing4 ,if a hole is countersunk it will retain the oil when a flat surface will not4 ,the idea of countersinking to obtain a shorter bearing will apply better to the fine clocks than to the ordinary4 ,in ordinary clocks the pivots must be longer than the thickness of the plates for the reason that freight is handled so roughly that short pivots will pop out of the plates and cause a lot of damage1 provided the springs are wound when the rough handling occurs4 ,it will be seen by reference to ,chapter ,,vii 7the mechanical elements of gearing71 ,figs4 #ba to #be1 that a wheel and pinion are merely a collection of levers adapted to continuous work1 that the teeth may be regarded as separate levers coming into contact with each other in succession2 this brings up two points4 ,the first is necessarily the relative proportions of those levers1 as upon these will depend the power and speed of the motion produced by their action4 ,the second is the shapes and sizes of the ends of our levers so that they shall perform their work with as little friction and loss of power as possible4 ,,to ,,get ,,center ,,distances4--,as the radii and circumferences of circles are proportional1 it follows that the lengths of our radii are merely the lengths of our levers 7,see ,fig4 #bd71 and that the two combined 7the radius of the wheel1 plus that of the pinion7 will be the distance at which we must pivot our levers 7our staffs or arbors of our wheels7 in order to maintain the desired proportions of their revolution4 ,consequently we can work this rule backwards or forwards4 ,for instance if we have a wheel and pinion which must work together in the proportion of #g to #a2 then #g #a #h and if we divide the space between centers into #h spaces we will have one of these spaces for the radius of the pitch circle of the pinion and #g for the pitch circle of the wheel1 ,fig4 #fe4 ,this is independent of the number of teeth so long as the proportions be observed2 thus our pinion may have eight teeth and the wheel sixty1 #fj #h #g4e1 or #ge #aj #g4e1 or #ij #ab #g4e1 or any other combination of teeth which will make the correct proportion between them and the center distances4 ,the reason is that the teeth are added to the wheel to prevent slipping1 and if they did not agree with each other and also with the proportionate distance between centers there would be trouble1 because the desired proportion could not be maintained4 ,now we can also work this rule backwards4 ,say we have a wheel of #hj teeth and the pinion has #aj leaves but they do not work together well in the clock4 ,tried in the depthing tool they work smoothly4 #hj #aj #h1 consequently our center distance must be as #h and #a4 #h #a #i2 the wheel must have #h parts and the pinion #a part of the radius of the pitch circle of the wheel4 ,measure carefully the diameter of the pitch circle of the wheel2 half of that is the pitch radius1 and nine-eighths of the pitch radius is the proper center distance for that wheel and pinion4 ,say we have lost a wheel2 the pinion has #ab teeth and we know the arbor should go seven and one-half times to one of the missing wheel2 we have our center distances established by the pivot holes which are not worn2 what size should the wheel be and how many teeth should it have8 #ab #g4e #ij1 the number of teeth necessary to contain the teeth of the pinion #g4e times4 #g4e #a #h4e1 the sum of the center distances2 the pitch radius of the pinion can be closely measured2 then #g4e times that is the pitch radius of the missing wheel of #ij teeth4 ,other illustrations with other proportions could be added indefinitely but we have1 we think1 said enough to make this point clear4 ,illustration3 ,fig4 #fe4 ,spacing off center distances2 c1 center of wheel2 e1 pitch circle2 d1 dedendum2 b1 addendum2 a1 center of pinion4 ,,conversion ,,of ,,numbers4--,there is one other point which sometimes troubles the student who attempts to follow the expositions of this subject by learned writers and that is the fact that a mathematician will take a totally different set of numbers for his examples1 without explaining why4 ,if you don't know why you get confused and fail to follow him4 ,it is done to avoid the use of cumbersome fractions4 ,to use a homely illustration3 ,say we have one foot1 six inches for our wheel radius and #d4e inches for our pinion radius4 ,if we turn the foot into inches we have #ah inches4 #ah #d4e #d1 which is simpler to work with4 ,now the same thing can be done with fractions4 ,in the above instance we got rid of our larger unit 7the foot7 by turning it into smaller units 7inches7 so that we had only one kind of units to work with4 ,the same thing can be done with fractions2 for instance1 in the previous example we can get rid of our mixed numbers by turning everything into fractions4 ,eighteen inches equals #cf halves and #d4e equals #i halves2 then #cf #i #d4 ,this is called the conversion of numbers and is done to simplify operations4 ,for instance in watch work we may find it convenient to turn all our figures into thousands of a millimeter1 if we are using a millimeter gauge4 ,say we have the proportions of #g4e to #a to maintain1 then turning all into halves1 #g #b #ae and #a #b #b4 #ae #b #ag parts for our center distance1 of which the pitch radius of the pinion takes #b parts and that of the wheel #ae4 ,,the ,,shapes ,,of ,,the ,,teeth4--,the second part of our problem1 as stated above1 is the shapes of the ends of our levers or the teeth of our wheels1 and here the first consideration which strikes us is that the teeth of the wheels approach each other until they meet2 roll or slide upon each other until they pass the line of centers and then are drawn apart4 ,a moment's consideration will show that as the teeth are longer than the distance between centers and are securely held from slipping at their centers1 the outer ends must either roll or slide after they come in contact and that this action will be much more severe while they are being driven towards each other than when they are being drawn apart after passing the line of centers4 ,this is why the engaging friction is more damaging than the disengaging friction and it is this butting action which uses up the power if our teeth are not properly shaped or the center distances not right4 ,generally speaking this butting causes serious loss of power and cutting of the teeth when the pivot holes are worn or the pivots cut1 so that there is a side shake of half the diameter of the pivots1 and bushing or closing the holes1 or new and larger pivots are then necessary4 ,this is for common work4 ,for fine work the center distances should be restored long before the wear has reached this point4 ,if we take two circular pieces of any material of different diameters and arrange them so that each can revolve around its center with their edges in contact1 then apply power to the larger of the two1 we find that as it revolves its motion is imparted to the other1 which revolves in the opposite direction1 and1 if there is no slipping between the two surfaces1 with a velocity as much greater than that of the larger disc as its diameter is exceeded by that of the larger one4 ,we have1 then1 an illustration of the action of a wheel and pinion as used in timepieces and other mechanisms4 ,it would be impossible1 however1 to prevent slipping of these smooth surfaces on each other so that power 7or motion7 would be transmitted by them very irregularly4 ,they simply represent the 8pitch0 circles or circles of contact of these two mobiles4 ,if now we divide these two discs into teeth so spaced that the teeth of one will pass freely into the spaces of the other and add such an amount to the diameter of the larger that the points of its teeth extend inside the pitch circle of the smaller1 a distance equal to about #a times the width of one of its teeth1 and to the smaller so that its teeth extend inside the larger one-half the width of a tooth1 the ends of the teeth being rounded so as not to catch on each other and the centers of revolution being kept the same distance apart1 on applying power to the larger of the two it will be set in motion and this motion will be imparted to the smaller one4 ,both will continue to move with the same relative velocity as long as sufficient power is applied4 ,other pairs of mobiles may be added to these to infinity1 each addition requiring the application of increased power to keep it in motion4 ,these pairs of mobiles as applied to the construction of timepieces are usually very unequal in size and the larger is designated as a 8wheel0 while the smaller1 if having less than #bj teeth1 is called a 8pinion0 and its teeth 8leaves40 ,now while we have established the principle of a train of wheels as used in various mechanisms1 our gearing is very defective1 for while continuous motion may be transmitted through such a train1 we will find that to do so requires the application of an impelling force far in excess of what should be required to overcome the inertia of the mobiles1 and the amount of friction unavoidable in a mechanism where some of the parts move in contact with others4 ,this excess of power is used in overcoming a friction caused by improperly shaped teeth1 or when formed thus the teeth of the wheel come in contact with those of the pinion and begin driving at a point in front of what is known as the 8line of centers10 i4 e41 a line drawn through the centers of revolution of both mobiles1 and as their motion continues the driven tooth slides on the one impelling it toward the center of the wheel4 ,when this line is reached the action is reversed and the point of the driving tooth begins sliding on the pinion leaf in a direction away from the center of the pinion1 which action is continued until a point is reached where the straight face of the leaf is on a line tangential to the circumference of the wheel at the point of the tooth4 ,it then slips off the tooth1 and the driving is taken up on another leaf by the next succeeding tooth4 ,the sliding action which takes place in front of the line of centers is called 8engaging10 that after this line has been passed 8disengaging0 friction4 ,now we know that in the construction of timepieces1 friction and excessive motive power are two of the most potent factors in producing disturbances in the rate1 and that1 while some friction is unavoidable in any mechanism1 that which we have just described may be almost entirely done away with4 ,let us examine carefully the action of a wheel and pinion1 and we will see that only that part of the wheel tooth is used1 which is outside the pitch circle1 while the portion of the pinion leaf on which it acts is the straight face lying inside this circle1 therefore it is to giving a correct shape to these parts we must devote our attention4 ,if we form our pinion leaves so that the portion of the leaf inside the pitch circle is a straight line pointing to the center1 and give that portion of the wheel tooth lying outside the pitch circle 7called the addenda1 or ogive of the tooth7 such a degree of curvature that during its entire action the straight face of the leaf will form a tangent to that point of the curve which it touches1 no sliding action whatever will take place after the line of centers is passed1 and if our pinion has ten or more leaves1 the 8addenda0 of the wheel is of proper height1 and the leaves of the pinion are not too thick1 there will be no contact in front of the line of centers4 ,with such a depth the only friction would be from a slight adhesion of the surfaces in contact1 a factor too small to be taken into consideration4 ,illustration3 ,showing that a hypocycloid of half the pitch circle is a straight line4 ,illustration3 ,generating an epicycloid curve for a cut pinion4 ,d1 generating circle4 ,dotted line epicycloid curve4 ,note how the shape varies with the thickness of the tooth4 ,here1 then1 we have an ideal depth4 ,how shall we obtain the same results in practice8 ,it is comparatively an easy matter to so shape our cutters that the straight faces of our pinion leaves will be straight lines pointing to the center1 but to secure just the proper curve for the addenda of our wheel teeth requires rather a more complicated manipulation4 ,this curve does not form a segment of a circle1 for it has no two radii of equal length1 and if continued would form1 not a circle1 but a spiral4 ,to generate this curve1 we will cut from cardboard1 wood1 or sheet metal1 a segment of a circle having a radius equal to that of our wheel1 on the pitch circle1 and a smaller circle whose diameter is equal to the radius of the pinion1 on the pitch circle4 ,to the edge of the small circle we will attach a pencil or metal point so that it will trace a fine mark4 ,now we lay our segment flat on a piece of drawing paper1 or sheet metal and cause the small circle to revolve around its edge without slipping4 ,we find that the point in the edge of the small circle has traced a series of curves around the edge of the segment4 ,these curves are called 8epicycloids10 and have the peculiar property that if a line be drawn through the generating point and the point of contact of the two circles1 this will always be at right angles to a tangent of the curve at its point of intersection4 ,it is this property to which it owes its value as a shape for the acting surface of a wheel tooth1 for it is owing to this that a tooth whose acting surface is bounded by such a curve can impel a pinion leaf through the entire lead with little sliding action between the two surfaces4 ,this1 then1 is the curve on which we will form the addenda of our wheel teeth4 ,in ,fig4 #ff1 the wheel has a radius of fifteen inches and the pinion a radius of one and one-half1 and these two measurements are to be added together to find the distance apart of the two wheels2 #af4e inches is then the distance that the centers of revolution are apart of the wheels4 ,now1 the teeth and leaves jointly act on one another to maintain a sure and equable relative revolution of the pair4 ,in ,fig4 #ff1 the pinion has its leaves radial to the center1 inside of the pitch line ,d1 and the ends of the leaves1 or those parts outside of the pitch line1 are a half circle1 and serve no purpose until the depthings are changed by wear1 as they never come in contact with the wheel2 the wheel teeth only touch the radial part of the pinion and that occurs wholly within the pitch line4 ,so in all pinions above #aj leaves in number the addendum or curve is a thing of no moment1 except as it may be too large or too long4 ,in many large pieces of machinery the pinions1 or small driven wheels1 have no addendum or extension beyond their pitch diameter and they serve every end just as well4 ,in watches there is so much space or shake allowed between the teeth and pinions that the end of a leaf becomes a necessity to guard against the pinion's recoiling out of time and striking its sharp corner against the wheel teeth and so marring or cutting them4 ,in a similar pair of wheels in machinery there are very close fits used and the shake between teeth is very slight and does not allow of recoil1 butting1 or 8running out of time40 ,running out of time is the sudden stopping and setting back of a pinion against the opposite tooth from the one just in contact or propelling4 ,this1 with pinions of suppressed ends1 is a fault and it is averted by maintaining the ends4 ,the wheel tooth drives the pinion by coming in contact with the straight flank of the leaf at the line of centers1 that is a line drawn through the centers of the two wheels2 centers of revolution4 ,the curve or end of the wheel tooth outside of the pitch line is the only part of the tooth that ever touches the pinion and it is the part under friction from pressure and slipping4 ,at the first point of contact the tooth drives the pinion with the greatest force1 as it is then using the shortest leverage it has and is pressing on the longest lever of the leaf4 ,as this action proceeds1 the tooth is acted on by the pinion leaf farther out on the curve of the wheel tooth1 thus lengthening the lever of the wheel and at the same time the tooth thus acts nearer to the center of the pinion by touching the leaf nearer its center of revolution4 ,by these joint actions it will appear that the wheel first drives with the greatest force and then as its own leverage lengthens and its force consequently decreases1 it acts on a shorter leverage of the pinion1 as the end of a tooth is nearer to the center of the pinion1 or on the shortest pinion leverage1 just as the tooth is about ceasing to act4 ,the action is thus shown from the above to be a variable one1 which starts with a maximum of force and ends with a minimum4 ,practically the variable force in a train is not recognized in the escapement1 as the other wheels and pinions making up the train are also in the same relations of maximum and minimum forces at the same time1 and thus this theoretical and virtual variability of train force is to a great extent neutralized at the active or escaping end of the movement4 ,there is another action between the tooth and leaf that is not easy to explain without somewhat elaborate sketches of the acting parts1 and as this is not consistent with such an article1 we may dismiss it1 and merely state that it is the one of maintaining the relative angular velocities of the two wheels at all times during their joint revolutions4 ,in ,fig4 #ff will be seen the teeth of the wheel1 their heights1 widths and spacing1 and the epicycloidal curves4 ,also the same features of the pinion's construction4 ,the curve on the end of the wheel teeth is the only curve in action during the rotation between wheel and pinion4 ,each flank 7both teeth and leaves7 is a straight line to the center of each4 ,a tooth is composed of two members--the pillar or body of the tooth inside of the pitch line and the cycloid or curve1 wholly outside of this line4 ,the pinion also has two members1 the radial flank wholly inside of the pitch line1 and its addendum or circle outside of this line4 ,illustration3 ,fig4 #ff4 ,in ,fig4 #ff will be seen a tooth on the line of centers ,a ,b1 just coming in action against the pinion's flank and also one just ceasing action4 ,it will be seen that the tooth just entering is in contact at the joint pitches1 or radii1 of the two wheels1 and that when the tooth has run its course and ceased to act1 that it will be represented by tooth #b4 ,then the exit contact will be at the dotted line o o4 ,from this may be seen just how far the tooth has1 in its excursion1 shoved along the leaf of the pinion and by the distance the line o o1 is from the wheel's pitch line ,g1 at this tooth4 ,no4 #b1 is shown the extent of contact of the wheel tooth4 ,by these dotted lines1 then1 it may be seen that the tooth has been under friction for nearly its whole curve's length1 while the pinion's flank will have been under friction contact for less than half this distance4 ,in brief1 the tooth has moved about _/ of its curved surface along the straight flank 4#ce of the surface of the pinion leaf4 ,from this relative frictional surface may be seen the reason why a pinion is apt to be pitted by the wheel teeth and cut away4 ,in any case it shows the relation between the two friction surfaces4 ,in part a wheel tooth rolls as well as slides along the leaf1 but whatever rolling there may be1 the pinion is also equally favored by the same action1 which leaves the proportions of individual friction still the same4 ,in ,fig4 #ff may be seen the spaces of the teeth and pinion4 ,the teeth are apart1 equal to their own width and the depths of the spaces are the same measurement of their width--that is1 the tooth 7inside of the pitch line7 is a pillar as wide as it is high and a space between two teeth is of like proportions and extent of surface4 ,the depth of a space between two teeth is only for clearance and may be made much less1 as may be seen by the pinion leaf1 as the end of the circle does not come half way to the bottom of a space4 ,the dotted line1 o o1 shows the point at which the tooth comes out of action and the pointed end outside of this line might be cut off without interfering with any function of the tooth4 ,they generally are rounded off in common clock work4 ,the pinion is #c inches diameter and is divided into twelve spaces and twelve leaves2 each leaf is two-fifths of the width of a space and tooth4 ,that is one-twelfth of the circumference of the pinion is divided into five equal parts and the leaf occupies two and a space three of these parts4 ,the space must be greater than the width of a leaf1 or the end of a leaf would come in contact with a tooth before the line of centers and cause a jamming and butting action4 ,also the space is needed for dirt clearance4 ,as watch trains actuated by a spring do not have any reserve force there must be allowance made for obstructions between the teeth of a train and so a large latitude is allowed in this respect1 more than in any machinery of large caliber4 ,as will be seen by ,fig4 #ff1 the spans between the leaves are deep1 much more so than is really necessary1 and a space at ,o ,c shows the bottom of a space1 cut on a circle which strengthens a leaf at its root and is the best practice4 ,having determined the form of our curve1 our next step will be to get the proper proportions4 ,saunier recommends that in all cases tooth and space should be of equal width1 but a more modern practice is to make the space slightly wider1 say one-tenth where the curve is epicycloidal4 ,when the teeth are cut with the ordinary ,swiss cutters1 which1 of course1 cannot be epicycloidal1 it is best to make the spaces one-seventh wider than the tooth4 ,this proportion will be correct except in the case of a ten-leaf pinion1 when1 if we wish to be sure the driving will begin on the line of centers1 the teeth must be as wide as the spaces2 but in this case the pinion leaf is made proportionately thinner1 so that the requisite freedom is thus obtained4 ,the height of the addenda of the wheel teeth above the pitch circle is usually given as one and one-eighth times the width of a tooth4 ,while this is approximately correct1 it is not entirely so1 for the reason that as we use a circle whose diameter is equal to the pitch radius of the pinion for generating the curve1 the height of the addenda would be different on the same wheel for each different numbered pinion4 ,so that if a wheel of #fj were cut to drive a pinion of #h1 the curve of this tooth would be found too flat if used to drive a pinion of #aj4 ,now1 since the pitch diameter of the pinion is to the pitch diameter of the wheel as the number of leaves in the pinion are to the number of teeth in the wheel1 in order to secure perfect teeth3 we must adopt for the height of the addenda a certain proportion of the radius or diameter of the pinion it is to drive1 this proportion depending on the number of leaves in the pinion4 ,a careful study of the experiments on this subject with models of depths constructed on a large scale1 shows that the proportions given below come the nearest to perfection4 ,when the pinion has six leaves the spaces should be twice the width of the leaves and the depth of the space a little more than one-half the total radius of the pinion4 ,the addenda of the pinion should be rounded1 and should extend outside the pitch circle a distance equal to about one-half the width of a leaf4 ,the addenda of the wheel teeth should be epicycloidal in form and should extend outside the pitch circle a distance equal to five-twelfths of the pitch radius of the pinion4 ,with these proportions1 the tooth will begin driving when one-half the thickness of a leaf is in front of the line of centers1 and there will be engaging friction from this point until the line of centers is reached4 ,this cannot be avoided with low numbered pinions without introducing a train of evils more productive of faulty action than the one we are trying to overcome4 ,there will be no disengaging friction4 ,when a pinion of seven is used1 the spaces of the pinion should be twice the width of the leaves1 and the depth of a space about three-fifths of the total radius of the pinion4 ,the addenda of the pinion leaves should be rounded1 and should extend outside the pitch circle about one-half the width of a leaf4 ,the addenda of the wheel teeth should be epicycloidal1 and the height of each tooth above the pitch circle equal to two-fifths of the pitch radius of the pinion4 ,there is less engaging friction when a pinion of seven is used than with one of six1 as the driving does not begin until two-thirds of the leaf is past the line of centers4 ,there is no disengaging friction4 ,with an eight-leaf pinion the space should be twice as wide as the leaf1 and the depth of a space about one-half the total radius of the pinion4 ,the addenda of the pinion leaves should be rounded and about one-half the width of a leaf outside the pitch circle4 ,the addenda of the wheel teeth should be epicycloidal1 and the height of each tooth above the pitch circle equal to seven-twentieths of the pitch radius of the pinion4 ,with a pinion of eight there is still less engaging friction than with one of seven1 as three-quarters of the width of a leaf is past the line of centers when the driving begins4 ,as there is no disengaging friction1 a pinion of this number makes a very satisfactory depth4 ,a pinion with nine leaves is sometimes1 though seldom1 used4 ,it should have the spaces twice the width of the leaves1 and the depth of a space one-half the total radius4 ,the addenda should be rounded1 and its height above the pitch circle equal to one-half the width of the leaf4 ,the addenda of the wheel teeth should be epicycloidal1 and the height of each tooth above the pitch circle equal to three-sevenths of the total radius of the pinion4 ,with this pinion the driving begins very near the line of centers1 only about one-fifth of the width of a leaf being in front of the line4 ,a pinion of ten leaves is the lowest number with which we can entirely eliminate engaging friction1 and to do so in this case the proper proportions must be rigidly adhered to4 ,the spaces on the pinion must be a little more than twice as wide as a leaf2 a leaf and space will occupy #cf of arc2 of this #aa should be taken for the leaf and #be for the space4 ,the addenda should be rounded and should extend about half the width of a leaf outside the pitch circle4 ,the depth of a space should be equal to about one-half the total radius4 ,for the wheel1 the teeth should be equal in width to the spaces1 the addenda epicycloidal in form1 and the height of each tooth above the pitch circle1 equal to two-fifths the pitch radius of the pinion4 ,a pinion having eleven leaves would give a better depth1 theoretically1 than one of ten1 as the leaves need not be made quite so thin to ensure its not coming in action in front of the line of centers4 ,it is seldom seen in watch or clock work1 but if needed the same proportions should be used as with one of ten1 except that the leaves may be made a little thicker in proportion to the spaces4 ,a pinion having twelve leaves is the lowest number with which we can secure a theoretically perfect action1 without sacrificing the strength of the leaves or the requisite freedom in the depths4 ,in this pinion1 the leaf should be to the space as two to three1 that is1 we divide the arc of the circumference needed for a leaf and space into five equal parts1 and take two of these parts for the leaf1 and three for the space2 depth of the space should be about one-half the total radius4 ,the addenda of the wheel teeth should be epicycloidal1 and the height of each tooth above the pitch line equal to two-sevenths the pitch radius of the pinion4 ,as the number of leaves is increased up to twenty1 the width of the space should be decreased1 until when this number is reached the space should be one-seventh wider than the leaf4 ,as these numbers are used chiefly for winding wheels in watches1 where considerable strength is required1 the bottoms of the spaces of both mobiles should be rounded4 ,,circular ,,pitch4 ,,diametral ,,pitch4--,in large machinery it is usual to take the circumference and divide by the number of teeth2 this is called the circular pitch1 or distance from point to point of the teeth1 and is useful for describing teeth to be cut out as patterns for casting4 ,but for all small wheels it is more convenient to take the diameter and divide by the number of teeth4 ,this is called the diametral pitch1 and when the diameter of a wheel or pinion which is intended to work into it is desired1 such diameter bears the same ratio or proportion as the number required4 ,both diameters are for their pitch circles4 ,as the teeth of each wheel project from the pitch circle and enter into the other1 an addition of corresponding amount is made to each wheel2 this is called the addendum4 ,as the size of a tooth of the wheel and of a tooth of the pinion are the same1 the amount of the addendum is equal for both2 consequently the outside diameter of the smaller wheel or pinion will be greater than the arithmetical proportion between the pitch circles4 ,as the diameters are measured presumably in inches or parts of an inch1 the number of a wheel of given size is divided by the diameter1 which gives the number of teeth to each inch of diameter1 and is called the diametral pitch4 ,in all newly-designed machinery a whole number is used and the sizes of the wheels calculated accordingly1 but when1 as in repairing1 a wheel of any size has any number of teeth1 the diametral number may have an additional fraction1 which does not affect the principle but gives a little more trouble in calculation4 ,take for example a clock main wheel and center pinion3 ,assuming the wheel to be exactly three inches in diameter at the pitch line1 and to have ninety-six teeth1 the result will be #if #c #cb1 or #cb teeth to each inch of diameter1 and would be called #cb pitch4 ,a pinion of #h to gear with this wheel would have a diameter at the pitch line of #h of these thirty-seconds of an inch or _/ of an inch4 ,but possibly the wheel might not be of such an easily manageable size4 ,it might1 say1 be #c4be inches1 in which case1 #if being the number of the wheel and #h of the pinion1 the ratio is _/ or _/1 so _/ of #c4be #j4bgj1 the pitch diameter of the pinion4 ,these two examples are given to indicate alternative methods1 the most convenient of which may be used4 ,after arriving at the true pitch diameters the matter of the addendum arises1 and it is for this that the diametral number is specially useful1 as in every case when figuring by this system1 whatever the number of a wheel or pinion1 two of the pitch numbers are to be added4 ,thus with the #cb pitch1 the outside diameter of the wheel will be #c in4 _/1 and if the pinion _/ _/ _/4 ,with the other method the same exactness is more difficult of attainment1 but for practical purposes it will be near enough if we use _/ of an inch for the addendum1 when the result will be #c4be _/ or #c _/ #c2 in4 nearly and the pinion #j4bgj _/ #j4bgj 4#jfff #j4ccff2 or to work by of an inch is near enough1 giving the outside diameter of the pinion a small amount less than the theoretical1 which is always advisable for pinions which are to be driven4 ,we represent by ,figs4 #fg to #ga a wheel of sixty teeth gearing with a pinion of six leaves4 ,the wheel1 whose pitch diameter is represented by the line mm is the same in each figure4 ,the pinion1 which has for its pitch diameter the line kk1 is in ,fig4 #fg1 of a size proportioned to that of the wheel1 and its center is placed at the proper distance2 that is to say1 the two pitch diameters are tangential4 ,in ,fig4 #fh the same pinion1 of the proper size1 has its center too far off2 the depthing is too shallow4 ,in ,fig4 #fi it is too deep4 ,figs4 #gj and #ga represent gearing in which the pitch circles are in contact1 as the theory requires1 but the size of the pinions is incorrect4 ,if the wheels and pinion actuated each other by simple contact the velocity of the pinion with reference to that of the wheel would not be absolutely the same2 but the ratio of the teeth being the same1 the same ratio of motion obtains in practice1 and there is necessarily bad working of the teeth with the leaves4 ,we will observe what passes in each of these cases1 and refer to the suitable remedies for obtaining a passable depthing and a comparatively good rate1 without the necessity of repairs at a cost out of all proportion with the value of the article repaired4 ,illustration3 ,fig4 #fg4 ,fig4 #fg represents gearing of which the wheel and pinion are well proportioned and at the proper distance from each other4 ,its movement is smooth1 but it has little drop or none at all4 ,by examining the teeth h1 h1 of the wheel1 it is seen that they are larger than the interval between them4 ,with a cutter ,,ff1 introduced between the teeth1 they are reduced at d1 d1 which gives the necessary drop without changing the functions1 since the pitch circles mm and kk have not been modified4 ,the drop1 the play between the tooth d and the leaf a1 is sufficiently increased for the working of the gearing with safety4 ,we have the same pair in ,fig4 #fh1 but here their pitch circles do not touch2 the depthing is too shallow4 ,the drop is too great and butting is produced between the tooth h and the leaf r1 which can be readily felt4 ,the remedy is in changing the center distance1 by closing the holes1 if worn1 or moving one nearer the other4 ,but in an ordinary clock this wheel may be replaced with a larger one1 whose pitch circle reaches to e4 ,the proportions of the pair are modified1 but not sufficiently to produce inconvenience4 ,illustration3 ,fig4 #fh4 ,it may also answer to stretch the wheel1 if it is thick enough to be sufficiently increased in size4 ,a cutter should then be selected for rounding-up which will allow the full width to the tooth as at p2 but if it is not possible to enlarge the wheel enough1 a little of the width of the teeth may be taken off1 as is seen at h1 which will diminish the butting with the leaf r4 ,too great depthing1 ,fig4 #fi1 can generally be recognized by the lack of drop4 ,when the teeth of the wheel are narrow1 the drop may appear to be sufficient4 ,when the train is put in action the depthing that is too great produces scratching or butting and the 'scape wheel trembles4 ,this results from the fact that the points of the teeth of the wheel touch the core of the pinion and cause it to butt against the leaf following the one engaged1 as is visible at r in ,fig4 #fi4 ,it should be noticed that in this figure the pitch circles mm and kk overlap each other1 instead of being tangential4 ,illustration3 ,fig4 #fi4 ,illustration3 ,fig4 #gj4 ,to correct this gearing1 the cutter should act only on the addenda of the teeth of the wheel1 so as to diminish them and bring the pitch circle mm to n4 ,the dots in the teeth d1 d1 show the corrected gearing4 ,it is seen that there will be1 after this change1 the necessary drop1 and that the end of the tooth d will not touch the leaf r4 ,in the two preceding cases we have considered wheels and pinions of accurate proportion1 and the defects of the gearing proceeding from the wrong center distances4 ,we will not speak of the gearing in which the pinion is too small4 ,the only theoretic remedy in this case1 as in that of too large a pinion1 is to replace the defective piece2 but in practice1 when time and money are to be saved1 advantage must be taken1 one way or another1 of what is in existence4 ,the buzzing produced when the train runs in a gearing with too small a pinion proceeds from the fact that each tooth has a slight drop before engaging with the corresponding leaf4 ,if we examine ,fig4 #gj1 it will be easy to see how this drop is produced4 ,the wheel revolving in the direction indicated by the arrow1 it can be seen that when the tooth h leaves the leaf r1 the following tooth1 p1 does not engage with the corresponding leaf1 s2 this tooth will therefore have some drop before reaching the leaf4 ,a friction may even be produced at the end or addendum of the tooth p against the following leaf v4 ,to obtain a fair depthing without replacing the pinion1 the wheels can be passed to the rounding-up machine1 having a cutter which will take off only the points of the teeth1 as is indicated in the figure2 the result may be observed by the dotted lines4 ,the tooth h being shorter1 it will leave the leaf r of the pinion when the latter is in the dotted position2 that is to say1 a little sooner4 ,at this moment the tooth p is in contact with the leaf s1 and there is no risk of friction against the leaf v4 ,care must be taken to touch only the addendum of the tooth so as not to weaken the teeth4 ,the circumference i will be that of a pinion of accurate size1 and if the pinion is replaced1 it will be necessary to diminish the wheel so that its pitch circle shall be tangential with i4 ,illustration3 ,fig4 #ga4 ,with too small a pinion a passable gearing can generally be produced4 ,in any case stoppage can be prevented4 ,this is not so easy when the pinion is too large4 ,in ,fig4 #ga1 the pinion has as its pitch circle the line k1 instead of i1 which would be nearer the size with reference to that of the wheel4 ,this is purposely drawn a little small for clearness of illustration4 ,the essential defect of such a gearing can be seen2 the butting produced between the tooth p and the leaf s will cause stoppage4 ,how shall this defect be corrected without replacing the pinion8 ,to remedy the butting as far as possible1 some watchmakers slope the teeth of the wheel by decentering the cutter on the rounding-up machine4 ,at ,,ff the cutter is seen working between the teeth d and d4 ,it is evident that when the wheel becomes smaller it is necessary to stretch it out1 and to make use of the cutter afterwards4 ,however1 the most rational method is to leave the teeth straight1 and to give them the slenderest form possible1 after having enlarged the wheel or having replaced it with another4 ,the motive force of the wheel being sufficiently weak1 the size of the teeth may be reduced without fear4 ,the essential thing is to suppress the butting4 ,success will be the easiest when the teeth are thinner4 ,in conclusion1 we recommend verification of all suspected gearings by the depthing tool1 which is easier and surer than by the clock itself4 ,one can see better by the tool the working of the teeth with the leaves1 and can form a better idea of the defect to be corrected4 ,with the aid of the illustrations that have been given it can be readily noticed whether the depthing is too deep or too shallow1 or the pinion too large or too small4 ,the defects mentioned are of less consequence in a pinion of seven leaves1 and they are corrected more readily4 ,with pinions of higher numbers the depthings will be smoother1 provided sufficient care has been taken in the choice of the rounding-up cutters4 ,,rounding-,,up ,,wheels4--,it is frequently observed that young watchmakers1 and 7regretfully be it said7 some of the older and more experienced ones1 are rather careless when fitting wheels on pinions4 ,in many cases the wheel is simply held in the fingers and the hole opened with a broach1 and in doing this no special care is taken to keep the hole truly central and of correct size to fit the pinion snugly1 and should it be opened a little too large it is riveted on the pinion whether concentric or not4 ,many suppose the rounding-up tool will then make it correct without further trouble and without sufficient thought of the irregularities ensuing when using the tool4 ,to make the subject perfectly clear the subjoined but rather exaggerated sketch is shown1 ,fig4 #gb4 ,of course1 it is seldom required to round-up a wheel of twelve teeth1 and the eccentricity of the wheel would be hardly as great as shown2 nevertheless1 assuming such a case to occur the drawing will exactly indicate the imperfections arising from the use of a rounding-up tool4 ,illustration3 ,fig4 #gb4 ,presuming from the drawing that the wheel1 as shown by dotted lines1 had originally been cut with its center at m1 but through careless fitting had been placed on the pinion at o1 and consequently is very much out of round when tested in the calipers1 and to correct this defect it is put in the rounding-up tool4 ,the cutter commences to remove the metal from tooth #g1 it being the highest1 next the neighboring teeth #f and #h1 then #e and #i1 and so on until tooth #a comes in contact with the cutter4 ,the wheel is now round4 ,but how about the size of the teeth and the pitch8 ,the result of the action of the cutter is shown by the sectionally lined wheel4 ,many will ask how such1 a result is possible1 as the cutter has acted equally upon all the teeth4 ,nevertheless1 a little study of the action of the rounding-up cutter will soon make it plain why such faults arise4 ,naturally the spaces between the teeth through the action of the cutter will be equal1 but as the cutter is compelled to remove considerable metal from the point of greatest eccentricity1 i4 e41 at tooth #g and the adjoining teeth1 to make the wheel round1 and the pitch circle being smaller the teeth become thinner1 as the space between the teeth remains the same4 ,at tooth #a no metal was removed1 consequently it remains in its original condition4 ,the pitch from each side of tooth #a becomes less and less to tooth #g1 and the teeth thinner1 and the thickest tooth is always found opposite the thinnest4 ,in the case of a wheel having a large number of teeth and the eccentricity of which is small1 such faults as described cannot be readily seen1 from the fact that there are many teeth and the slight change in each is so gradual that the only way to detect the difference is by comparing opposite teeth4 ,and this eccentricity becomes a serious matter when there are but few teeth1 as before explained1 especially when reducing an escape wheel4 ,the only proper course to pursue is to cement the wheel on a chuck1 by putting it in a step chuck or in any suitable manner so that it can be trued by its periphery and then opening the hole truly4 ,this method is followed by all expert workmen4 ,a closer examination of the drawing teaches us that an eccentric wheel with pointed teeth--as cycloidal teeth are mostly left in this condition when placed in the rounding-up tool1 will not be made round1 because when the cutter has just pointed the correct tooth 7tooth ,no4 #a in the drawing7 it will necessarily shorten the thinner teeth4 ,nos4 #f1 #g1 #h1 i4 e41 the pitch circle will be smaller in diameter4 ,we can1 therefore1 understand why the rounding-up tool does not make the wheel round4 ,as we have before observed1 when rounding-up an eccentrically riveted wheel1 the thickest tooth is always opposite the thinnest1 but with a wheel which has been stretched the case is somewhat different4 ,most wheels when stretched become angular1 as the arcs between the arms move outward in a greater or less degree1 which can be improved to some extent by carefully hammering the wheel near the arms1 but some inequalities will still remain4 ,in stretching a wheel with five arms we therefore have five high and as many depressed parts on its periphery4 ,if this wheel is now rounded-up the five high parts will contain thinner teeth than the depressed portions4 ,notwithstanding that the stretching of wheels1 though objectionable1 is often unavoidable on account of the low price of repairs1 it certainly ought not to be overdone4 ,before placing the wheel in the rounding-up tool it should be tested in the calipers and the low places carefully stretched so that the wheel is as nearly round as can be made before the cutter acts upon it4 ,it is hardly necessary to mention that the rounding-up tool will not equalize the teeth of a badly cut wheel1 and further should there be a burr on some of the teeth which has not been removed1 the action of the guide and cutter in entering a space will not move the wheel the same distance at each tooth1 thus producing thick and thin teeth4 ,from what has been said it would be wrong to conclude that the rounding-up tool is a useless one2 on the contrary1 it is a practical and indispensable tool1 but to render good service it must be correctly used4 ,in the use of the rounding-up tool the following rules are to be observed3 #a4 ,in a new wheel enlarge the hole after truing the wheel from the outside and stake it concentrically on its pinion4 #b4 ,in a rivetted but untrue wheel1 stretch the deeper portions until it runs true1 then reduce it in the rounding-up tool4 ,the better method is to remove the wheel from its pinion1 bush the hole1 open concentrically with the outside and rivet1 as previously mentioned in a preceding paragraph4 ,but if the old riveting cannot be turned so that it can be used again it is best to turn it entirely away1 making the pinion shaft conical towards the pivot1 and after having bushed the wheel1 drill a hole the proper size and drive it on the pinion4 ,the wheel will be then just as secure as when rivetted1 as in doing the latter the wheel is often distorted4 ,with a very thin wheel allow the bush to project somewhat1 so that it has a secure hold on the pinion shaft and cannot work loose4 #c4 ,should there be a feather edge on the teeth1 this should be removed with a scratch brush before rounding it up1 but if for some reason this cannot well be done1 then place the wheel upon the rest with the feather edge nearest the latter so that the cutter does not come immediately in contact with it4 ,if the feather edge is only on one side of the tooth--which is often the case--place the wheel in the tool so that the guide will turn it from the opposite side of the tooth2 the guide will now move the wheel the correct distance for the cutter to act uniformly4 ,of course1 in every case the guide1 cutter and wheel1 must be in correct position to ensure good work4 #d4 ,to obtain a smooth surface on the face of the teeth a high cutter speed is required1 and for this reason it is advantageous to drive the cutter spindle by a foot wheel4 ,,making ,,single ,,pinions4--,there are two ways of making clock pinions2 one is to take a solid piece of steel of the length and diameter needed and turn away the surplus material to leave the arbor and the pinion head of suitable dimensions2 the other way is to make the head and the arbor of separate pieces2 the head drilled and fixed on the arbor by friction4 ,the latter plan saves a lot of work1 and the cutting of the teeth may be easier4 ,one method is as good as the other1 as the force on the train is very slight and the pinion head may be driven so tightly on the arbor as to be perfectly safe without any other fastening1 provided the arbor is given a very small taper1 4#jja inch in four inches4 ,the steel for the arbor may be chosen of such a size as to require very little turning1 and hardened and tempered to a full or pale blue before commencing turning it1 but the piece intended for the pinion head must be thoroughly annealed1 or it may be found impossible to cut the teeth without destroying a cutter1 which1 being valuable1 is worth taking care of4 ,pinions for ordinary work are not hardened2 as they are left soft by the manufacturers it would be nonsense for the repairer to put in one hardened pinion in a clock where all the others were soft4 ,pinions on fine work are hardened4 ,turning is done between centers to insure truth4 ,before commencing work on the pinion blanks it is advisable to try the cutters on brass rod1 turned to the exact size1 and if the rod is soft enough it will be found that the cutter will make the spaces before it is hardened1 which is a very important advantage1 admitting of correction in the form of the cutter if required2 only two or three teeth need be cut in the brass to enable one to see if they are suitable1 and if found so1 or after an alteration of the cutter1 the entire number may be cut round and the brass pinion made use of for testing its accuracy as to size and shape by laying the wheel along with it on a flat plate1 having studs placed at the proper center distance4 ,by this means the utmost refinement may be made in the diameter of the brass pinion1 which will then serve as a gauge for the diameter of the steel pinions1 it being recollected1 as mentioned in a previous paragraph1 that a slight variation in the diameter of a pinion may be made to counterbalance a slight deviation from mathematical accuracy in the form of the wheel teeth1 such as is liable to occur owing to the smallness of the teeth making it impracticable to actually draw the true curves1 the only way of getting them being to draw them to an enlarged scale on paper1 and copy them on the cutter as truly as possible by the eye4 ,supposing the cutter has been properly shaped1 hardened and completed and the steel pinion heads all turned to the diameter of the brass gauge1 the cutting may be proceeded with without fear of spoiling1 or further loss of time which might be spent in cutting the long pinion leaves2 and even what is of more importance in work which does not allow of any imperfection1 removing the temptation1 which might be strong1 to let a pinion go1 knowing it to be less perfect than it should be4 ,assuming the pinion teeth to be satisfactorily cut1 the next operation will be hardening and tempering4 ,a good way of doing this is to enclose one at a time in a piece of gas pipe1 filling up the space around the pinion with something to keep the air off the work and prevent any of the products of combustion attacking the steel and so injuring the surface4 ,common soap alone answers the purpose very well1 or it may have powdered charcoal mixed with it2 also the addition of common salt helps to keep the steel clean and white4 ,the heating should be slow1 giving time for the pinion and the outside of the tube to both acquire the same heat4 ,over-heating should be carefully avoided1 or there will be scaling of the surfaces1 injurious to the steel1 and requiring time and labor to polish off4 ,there is no better way of hardening than by dipping the pipe with the pinion enclosed in plain cold water1 or if the pinion should drop out of the tube into the water it will do all the same4 ,to be sure the hardening is satisfactory it will be as well not to trust to the clean white color likely to result from this treatment1 but try both ends and the center with a file4 ,after all this has been successfully accomplished the pinions will require tempering1 the long arbors straightening1 and the teeth polishing4 ,the drilled pinion heads1 if hardened at all by the method last mentioned1 will1 on account of their short lengths1 be equally hardened all over1 but if the pinion and arbor should be all in one piece care will be needed to ensure equal heating all over1 or one part may be burnt and another soft4 ,also1 to guard against bending the long arbors1 the packing in the tube will need to be carefully done1 so as to produce equal pressure all over2 otherwise1 while the steel is red hot1 and consequently soft enough to bend1 even by its own weight1 it may get distorted before dropping in the water4 ,a long thin rod like this almost invariably bends if heated on an open fire unless equally supported all along2 if hardened so1 a little tin tray may be bent up1 filled with powdered charcoal1 and the pinion bedded evenly in it4 ,either this way or with a tube the long arbor may get bent before being quenched2 but if the arbor1 though kept straight up to this point1 should happen to be dropped sideways into the water the side cooled first would contract most4 ,to avoid this1 the arbor should be dropped endways1 as vertically as possible4 ,,tempering ,,the ,,pinions4--,for common cheap work the usual and quickest way is what is called 8blazing off40 ,that is done either by dipping each piece singly in thick oil and setting the oil on fire1 allowing it to burn away1 or placing a number of pieces in a suitably sized pan1 covering with oil1 and burning it4 ,the result is the same either way1 the method being simply a matter of convenience regulated by the number of pieces to be tempered at one time4 ,as the result of blazing off is to some extent uncertain1 and the pinions apt to be too soft1 it will be advisable to adopt the process of bluing1 by which the temper desired may be produced with more accuracy4 ,the first thing to do will be to clean the surface of the arbor all along on one side2 the pinion head may be left alone4 ,as the pinion head would get overheated before the arbor had reached the blue color1 if the piece were simply placed on a bluing pan or a lump of hot iron1 it will be necessary to provide a layer of some soft substance to bed the pinion on2 iron1 steel or brass filings answer well because the heat is soon uniformly distributed through the mass1 and by judiciously moving the lamp an equable temper may be got all along1 as determined by the color4 ,there is another and very sure way of getting a uniform temper1 in using which there is no need to polish the arbors4 ,the heat of lead at the point of fusion happens to be just about the same as that required for the tempering of this work2 so if a ladle full of lead is available each pinion may be buried in it for a few seconds1 holding it down beneath the molten surface with hot pliers4 ,the temper suitable is indicated by a pale blue1 a little softer than for springs1 and a piece of polished steel set floating on the lead will indicate whether the heat is suitable2 if found too great some tin may be added1 which will cause the metal to melt at a lower temperature4 ,over-heating the metal must be avoided3 it should go no higher than the bare melting point4 ,,straightening ,,bent ,,arbors4--,when all care has been taken in the hardening1 the long pieces of wire are still apt to become bent more or less1 and this is especially the case with solid pinions2 so before proceeding further the pieces must be got true1 or as nearly so as possible1 and it will be found impracticable to do this by simple bending when the steel is tempered4 ,if the piece is placed between centers in the lathe and rotated slowly1 the hollow side will be found2 this side must be kept uppermost while the steel is held on a smooth anvil1 and the pene1 or chisel-shaped1 end of a small hammer applied crossways with gentle blows1 stepping evenly along so that each portion of the steel is struck all along the part which is hollow2 this will stretch the hollow side1 and1 by careful working1 trying the truth from time to time1 the piece can be got as true as may be wished1 and probably keep so during the subsequent turning and finishing1 though it is advisable to keep watch on it1 and if it shows any tendency to spring out of truth again1 repeat the striking process1 which should always be done gently and in such a way as to show no hammer marks4 ,having got the pieces sufficiently true in this way1 each arbor may have a collet of suitable size driven on to it for permanency1 and as the collets will probably be a little out of truth they may have a finishing cut taken all over them and receive a final polish4 ,,polishing4--,to polish the steel arbors after turning1 a flat metal polisher1 iron or steel1 is used2 this with emery or oilstone dust and oil produces a true surface1 with a sharp corner at the shoulder2 the polisher will require frequent filing on the flat and the edge to keep it in shape with a sharp corner1 and a grain crossing like the cuts on a file to hold the grinding material4 ,the polishing of arbors is not done with the object of making them shine1 but to get them smooth and true1 so there is no need of using any finer stuff than emery or oilstone dust4 ,an old way to polish the leaves was to use a simple metal polisher of a suitable thickness1 placing the pinion on a cork or piece of wood1 or even holding it in the fingers2 working away at a tooth at a time until a good enough polish was obtained2 but this method1 while being satisfactory as to results1 was also tedious and very slow4 ,it was in some cases assisted by having guide pinions fitted tight on one or both ends of the arbors to prevent rounding of the teeth1 the polisher resting in the guide and the tooth to be polished4 ,on the ,american lathes an accessory is provided called a 8wig wag40 ,this is a rod fastened at one end to a pulley by a crank pin near its circumference2 the pulley being rotated by a belt from the counter shaft pulleys causes the rod to move rapidly backwards and forwards4 ,on the other end of the rod a long narrow piece of lead or tin is fixed1 the pinion being fitted by its centres into a simple frame held in the slide rest so that it can be rotated tooth by tooth2 the lead soon gets cut to the form of the teeth1 and the polishing is quickly effected4 ,another way is to take soft pine or basswood1 shape it roughly to about the form of space between two teeth and use it as a file1 with emery and oil or oilstone dust4 ,the wood is soon cut to the exact shape of the teeth1 and then makes a quick and perfect job4 ,the pinion is held in the jaws of the vise and the wooden polisher used as a file with both hands4 ,where there is much polishing to do a simple tool1 which a workman can form for himself1 produces a result which is all that can be desired4 ,it consists of an arbor to work between the lathe centres1 or a screw chuck for wood1 with a round block of soft wood1 of a good diameter1 fixed on it1 and turned true and square across2 this will get a spiral groove cut in it by the corners of the pinion leaves4 ,the pinion is set between centres in a holder in the slide rest1 with the holder set at a slight angle1 so that1 instead of circular grooves being cut in the wood a screw will be formed1 the angle being found by trial4 ,on the wood block being rotated and supplied with fine emery the pinion will be found to rotate1 and1 being drawn backwards and forwards by the slide rest1 can be polished straight1 while the circular action of the polisher will cause the sides of the pinion leaves to be made quite smooth and entirely free from ridges4 ,if it should be desired to face the pinions1 like watch pinions1 it may be done in the same way1 by cutting hollows so as to leave only a fine ring round the bottoms of the teeth1 and using a hollow polisher with a flat end held in the fingers while the pinion is rotating4 ,a common cartridge shell with a hole larger than the arbor drilled in the center of the head makes a fine polisher for square facing on the ends of pinions1 while a stick of soft wood will readily adapt itself to moulded ends4 ,the pinion heads being finished and got quite true1 the arbors may be turned true and polished4 ,it is not advisable to turn the arbors small2 they will be better left thick so as to be stiff and solid1 as the weight so near the center is of no importance1 the velocity on the small circumference in starting and stopping being also inappreciable4 ,the thickness of the arbors when the pinion heads are drilled is determined by the necessity of having sufficient body inside the bottoms of the teeth2 but when solid they may with advantage be left thicker2 however1 there is no absolute size4 ,the ends on which the collets for holding the wheels are to be fixed may be turned to the same taper as the broach which will be used for opening the collet holes1 while the other ends may be straight4 ,none of the wheels in a fine clock should be riveted to the pinion heads2 even the center wheel1 which goes quite up to the pinion head1 is generally fixed on a collet4 ,the collets are made from brass cut off a round rod1 the outside diameters being just inside the edges of the wheel hubs1 and a shoulder turned to fit accurately into the center hole of each wheel4 ,these collets should first have their holes broached to fit their arbors1 allowing a little for driving on1 as they may be made tight enough in this way without soldering4 ,be careful to keep the broach oiled to prevent sticking if you want a smooth round hole4 ,the holes in the wheels being made1 each collet may be turned to a little over its final size all over1 and then driven on to its place on the pinion1 so that a final turning may be made to ensure exact truth from the arbors' own centers4 ,when the collets are thus finished in their places on the arbors1 and the wheels fitted to them1 if it is a fine clock1 such as a regulator1 a hole may be drilled through each wheel and its collet to take a screw1 the holes in the collet tapped1 the holes in the wheels enlarged to allow the screw to pass freely through1 and a countersink made to each1 so that the screws1 when finished1 may be flush with the wheels4 ,one hole having been thus made and the wheel fixed with a screw1 the other two holes can be made so as to be true1 which would not be so well accomplished if all the holes were attempted at once4 ,the spacing of the three screws will be accurate enough if the wheel arms be taken as a guide4 ,if all this has been correctly done1 the wheels will go to their places quite true1 both in the round and the flat1 and may be taken off for polishing1 and replaced true with certainty1 any number of times4 ,the polishing of the pivots should be as fine as possible2 all should be well burnished1 to harden them and make them as smooth as possible if it is a common job2 if a fine one with hardened arbors the pivots may be ground and polished as in watch work2 if the workman has a pivot polisher and some thin square edged laps this is a short job and should be done before cutting off the centers and rounding the ends of the pivots4 ,during all this work the wheels1 as a matter of course1 will be removed from the pinions1 and may now be again temporarily screwed on1 the polishing of them being deferred till the last1 as otherwise they would be liable to be scratched4 ,,lantern ,,pinions4--,the lantern pinion is little understood outside of clock factories and hence it is generally underrated1 especially by watchmakers and those working generally in the finer branches of mechanics4 ,it will never be displaced in clock work1 however1 on account of the following specific advantages3 #a4 ,it offers the greatest possible freedom from stoppage owing to dirt getting into the pinions1 as if a piece large enough to jam and stop a clock with cut pinions1 gets into the lantern pinion1 it will either fall through at once or be pushed through between the rounds of the pinion by the tooth of the wheel and hence will not interfere with its operation4 ,it is therefore excellently adapted to run under adverse circumstances1 such as the majority of common clocks are subjected to4 #b4 ,without giving the reasons it is demonstrable that as smooth a motion may be got by a lantern pinion as by a solid radial pinion of twice the number1 and that the force required to overcome the friction of the lantern is therefore much less than with the other4 ,it follows that such pinions can be used with advantage in the construction of all cheap and roughly constructed clocks which are daily turned out in thousands to sell at a low price4 #c4 ,we have before pointed out the enormous advantages of small savings per movement in clock factories which are turning out an annual product of millions of clocks1 and without going into details1 it is sufficient to refer to the fact that where eight or ten millions of clocks are to be made annually the difference in the cost of keeping up the drills and other tools for lantern pinions over the cost of similar work on the cutters for solid pinions is sufficient to have a marked influence upon the cost of the goods4 ,then the rapidity with which they can be made and the consequent smallness of the plant as compared with that which must be provided for turning out an equal number of cut pinions is also a factor4 ,there are other features1 but the above will be sufficient to show that it is unlikely that the lantern pinion will ever be displaced in the majority of common clocks4 ,from seventy-five to ninety per cent of the clocks now made have lantern pinions4 ,the main difference between lantern and cut pinions mechanically is that as there is no radial flank for the curve of the wheel tooth to press against in the lantern pinion the driving is all done on or after the line of centers1 except in the smaller numbers1 and hence the engaging or butting friction is entirely eliminated when the pinion is driven1 as is always the case in clock work4 ,where the pinion is the driver1 however1 this condition is reversed and the driving is all before the line of centers1 so that it makes a very bad driver and this is the reason why it is never used as a driving pinion4 ,this1 of course1 bars it from use in a large class of machinery4 ,the actual making of lantern pinions will be found to offer no difficulties to those who possess a lathe with dividing arrangements1 a slide rest1 and a drill holder or pivot polisher to be fixed on it4 ,the pitch circle1 being through the centers of the pins1 can be got with great accuracy by setting the drill point first to the center of the lathe1 reading the division on the graduated head of the slide rest screw1 and moving the drill point outwards to the exact amount of the semi-diameter of the pitch circle4 ,this presupposes the slide rest screw being cut to a definite standard1 as the inch or the meter1 and all measurements of wheels and pinions being worked out to the same standard1 the choice of the standard being immaterial4 ,if the slide rest screw is not standardized the pitch circle may be traced with a graver and the drill set to center on the line so traced4 ,the heads of the pinions may be made either of two separate discs1 each drilled separately1 and carefully fitted on the arbor so that the pins may be exactly parallel with the arbor2 or1 of one solid piece bored through the center1 turned down deep enough in the middle1 and the drill sent right through the pin holes for both sides at one operation4 ,the former way will be necessary when the number of pins is small1 but the latter is better when the numbers are large enough to allow of considerable body in the center4 ,in either case it is advisable to drill only part way through one shroud and to close the holes in the other with a thin brass washer pressed on the arbor and turned up to look like part of the shroud after the pins are fitted in the holes4 ,this makes a much neater way of closing the holes than riveting and takes but a moment where only one or two pinions are being made4 ,there is no essential proportion for the thickness of the pins or rounds4 ,in mathematical investigations these are always taken at first as mere points of no thickness at all2 then the diameters are increased to workable proportions1 and the width of the wheel tooth correspondingly reduced until there is a freedom or a little shake4 ,if much power has to be transmitted1 the pins1 or 8staves10 as they are called in large work1 have to be strong enough to stand the strain1 but1 as the strain in clockwork is very small1 the pins need not be nearly as thick as the breadth of a wheel tooth4 ,in modern factory practice the custom is to have the diameter of the rounds equal to the thickness of the leaf of a cut pinion of similar size1 the measurement being taken at the pitch circle of the cut pinion4 ,as we have already given the proportions observed in good practice on cut pinions they need not be repeated here4 ,another practice is to have wheel teeth and spaces equal2 when this is done the spacing of all pinions above six leaf is to have the rounds occupy three parts and the space five parts4 ,in some old church clocks1 lantern pinions were much used1 in many cases with the pins pivoted and working freely in the ends1 or1 as they called them1 8shrouds10 but this was a mistake1 and they are never made so now4 ,a simple way for clock repair work is to get some of the tempered steel drill rod of exactly the thickness desired1 hold one end by a split chuck in the lathe1 let the other end run free1 and polish with a bit of fine emery paper clipped round it with the fingers1 when the wire will be ready for driving through the pinion heads1 the holes being made small enough to provide for the rounds being firmly held4 ,the drill may be made of the same wire4 ,the shrouds may be made either of brass or steel2 the latter need not be hardened1 and1 when the rounds are all in place and cut off1 the ends may be polished as desired4 ,in the case of a center wheel1 where the pinion is close up to the wheel1 and space cannot be spared1 the collet on which the wheel is mounted may form one end of the pinion head4 ,illustration3 ,fig4 #gc4 ,lantern pinion showing pitch circle4 ,illustration3 ,fig4 #gd4 ,generating epicycloid curve for lantern pinion above2 compare with curve for cut pinion of same size pitch circle1 page #bjf4 ,,the ,,wheel ,,teeth4--,the same principles of calculation belong to these and solid-cut pinions1 the only difference being that the round pins require wheel teeth of a different shape from those suited to pinion leaves with radial sides4 ,both are derived from epicycloidal curves2 the curve used for lantern pinions is derived from a circle of the same size as the pitch circle of the pinion1 while the curve for wheel teeth to drive radial-sided leaves is derived from a circle of half that diameter1 so that the wheel teeth in the former are more pointed than in the latter4 ,there also is a farther difference2 as was explained in detail when treating of cut pinions1 the curve of the wheel tooth presses upon the radial flank of the leaf inside its pitch circle4 ,now there is no radial flank in the lantern and the curve is generated from a circle of twice the diameter1 so that it is twice as long--long enough to interfere--so it is cut off 7rounded7 just beyond the useful portion of the working curve of the wheel tooth4 ,pillars and arbors are simple parts1 yet much costly machinery is used in making them4 ,the wire from which they are made is brought to the factories in large coils1 and is straightened and cut into lengths by machines4 ,the principle on which wire is straightened in a machine is exactly the same as a slightly curved piece of wire is made straight in the lathe by holding the side of a turning tool between the revolving wire and the lathe rest1 which is an operation most of our readers must have practiced4 ,the rapid revolution of the wire against the turning tool causes its highest side to yield1 till finally it presses on the turning tool equally all round1 and is consequently straight4 ,however1 in straightening wire by machines the wire is not made to revolve1 but remains stationary while the straightening apparatus revolves around it4 ,wire-straightening machines are usually made in the form of a hollow cylinder1 having arms projecting from the inside towards the center4 ,the cylinder is open at both ends1 and the arms are adjustable to suit the different thicknesses of wire4 ,the wire is passed through the ends of the cylinder1 and comes in contact with the arms inside4 ,a rapid rotary motion is then given to the cylinder1 which straightens the wire in the most perfect manner1 as it is drawn through1 without leaving any marks on it when the machine is properly adjusted4 ,the long spiral lines that are sometimes seen on the wire work of clocks is caused by this want of adjustment2 and they are produced in the same way as broad circular marks would be made in soft iron wire if the side of the turning tool was held too hard against it when straightening it in the lathe4 ,illustration3 ,fig4 #ge4 ,a ,slide ,gauge ,lathe4 ,after the wire has been straightened it is cut off into the required lengths1 and this operation is worthy of notice4 ,if the thick sizes of wire that are used were to be cut by the aid of a file or a chisel1 the ends would not be square1 and some time and material would be lost in the operation of squaring them2 and as economy of material as well as economy of labor is a feature in ,american clock manufacture1 wire of all sizes is sheared or broken off into lengths1 by being fed through round holes in the shears1 which act the same as when a steady pin is broken when a cock or bridge gets a sudden blow on the side1 or in the same manner as patent cutting plyers work4 ,the wire is not bent in the operation1 and both ends of it are smooth and flat4 ,the wire for the pillars is then taken to a machine to have the points made and the shoulders formed for the frames to rest against4 ,this machine is constructed like a machinist's bench lathe1 with two headstocks4 ,there is a live spindle running in both heads4 ,in the ends of these spindles1 that point towards the center of the lathe1 cutters are fastened1 and the one is shaped so that it will form the end and shoulder of the pillar that is to be riveted1 while the other is shaped so as to form the shoulder and point that is to be pinned4 ,between these two revolving cutters there is an arrangement1 worked by a screw in the end of a handle1 for holding the wire from which the pillar is to be made1 in a firm and suitable position4 ,the cutters are then made to act simultaneously on the ends of the wire by a lever acting on the spindles1 and the points and shoulders are in this way formed in a very rapid manner1 all of the same length and diameter4 ,these machines are in some points automatic4 ,the pieces of wire are arranged in quantities in a long narrow feed box that inclines towards the lathe1 and the mechanism for holding the wire is so arranged that when its hold is loosened on the newly made pillar1 the pillar drops out into a box beneath1 and a fresh piece of wire drops in and occupies its place4 ,in many of the factories1 some clocks are manufactured having screws in place of pins to keep the frames together1 and the pillars of these clocks are made in a different manner than that we have just described4 ,the wire that is used is not cut into short lengths1 but a turret lathe with a hollow spindle is used1 through which the wire passes1 and is held by a chuck1 when a little more than just the length that is necessary to make the pillar projects through the chuck4 ,the revolving turret head of the lathe has cutting tools projecting from it at several points4 ,one tool is adapted to bore the hole for the screw1 and when it is bored the next tool taps the hole to receive the screw1 while another forms the point and shoulder2 and after that end of the pillar is completed another tool attached to the slide of the lathe forms the other shoulder1 prepares that end for riveting1 and cuts it off at the same time4 ,one thousand of these pillars are in this manner made in a day on each machine4 ,the screws that screw into them are made on automatic screw machines4 ,the latest improvements in this direction being to first turn the blanks and then roll the threads on thread rolling machines4 ,illustration3 ,fig4 #gf4 ,slide ,gauge ,tools and ,rack4 ,the pinion arbors1 after they have been cut to length1 are centered on one end by a milling machine having a conical cutter made for the purpose4 ,the collets for the pinion heads1 and the one to fasten the wheel by1 are punched out of sheet brass1 and a hole is drilled in their centers a little smaller than the wire2 and to drive them on1 in most instances1 is all that is necessary to hold them4 ,at one time it was the practice to drive these collets by hand4 ,one was placed on the point of the arbor1 and the point was then placed over a piece of steel1 with a series of holes in it of such depths that the collets would be in their proper position on the arbor when the point was driven to the bottom of the hole1 but this method has now been superseded by automatic machinery1 which will be described later4 ,it is impossible to give an intelligible description of these machines without drawings4 ,all we can say at present is that they perform their work in a very rapid and effective manner1 and are in use by all the larger clock factories4 ,the barrels of weight clocks are mostly made from brass castings1 and slight projections are raised on the surface of their arbors by swedging1 so as to prevent the arbors from getting loose in the barrels after repeated winding of the clock4 ,this swedging and all the other operations in making arbors used to be done on separate machines2 but the largest companies now use a powerful and comprehensive machine that works automatically1 and straightens any size of wire necessary to be used in a clock1 cuts it to the length1 centers it1 and also swedges the projections on the barrel arbors1 or any of the other arbors that may be necessary4 ,a roll of wire is placed on a reel at one end of the machine1 first passing through a straightening apparatus1 and afterwards to that portion of the machine where the cutting1 swedging and centering are executed1 and the finished arbors drop into a box placed ready to receive them4 ,the saving effected by the use of this machine is very great1 and in some instances amounts to a thousand per cent over the method of straightening1 cutting1 swedging and centering on different machines1 at different operations4 ,boring the holes in the arbors of the locking work1 to receive the smaller wires1 and the pin holes in the points of the pillars1 is done by small twist-drills1 run by small vertical drill presses4 ,the work is held in adjustable frames under the drill1 and when more than one hole has to be bored this frame is moved backward or forward between horizontal slides to the desired distance1 which is regulated by an adjustable stop1 so that every hole in each piece is exactly in the same position4 ,in arbors where holes have to be bored at right angles to each other1 the arbor is turned round to the desired position by means of an index4 ,the holes in the locking work arbors are bored just the size to fit the wire that is to go into them1 and these small wires are easily and rapidly fastened in place by holding them in a clamp made for the purpose1 and riveting them either with a hammer or with a hammer and punch4 ,illustration3 ,fig4 #gg4 ,automatic ,pinion ,making ,machine of the ,davenport ,machine ,company4 ,,the ,,slide ,,gauge ,,lathe4--,the system of turning with the slide gauge lathe1 formerly adopted for lantern pinions in the clock factories1 would seem to the watchmaker of a peculiarly novel nature4 ,the turning tools are not held in the hand1 in the manner generally practiced1 neither are they held in the ordinary slide rest1 but are used by a combination of both methods1 which secures the steadiness of the one plan and the rapidity of the other4 ,adjustable knees are fastened to the head and tail stocks of the lathe1 ,figs4 #ge and #gf1 which answer the purpose of a rest2 both the perpendicular and horizontal parts of these knees being fastened perfectly parallel with the centers of the lathe4 ,a straight1 round piece of iron1 of equal thickness1 and having a few inches in the center of a square shape1 mortised for the reception of cutters1 is laid on these knees1 and answers the purpose of a handle to hold the cutting tools4 ,two handles will thus hold eight tools1 one set for brass and one for steel4 ,on every side of the square part of this iron bar1 or what we will now call the turning tool handle1 a number of cutting tools are fastened by set screws1 and the method of using them is as follows3 ,the operator holds the tool handle with both hands on to the knees that are fastened to the head and tail stocks of the lathe1 with the turning tool that is desired to be used pointing towards the center1 and it is allowed to come in contact with the work running in the lathe in the usual manner practiced in turning4 ,fig4 #gf is from a photo furnished by ,mr4 ,h4 ,e4 ,smith of the ,smith ,novelty ,co41 ,hopewell1 ,n4 ,j41 and shows the tools in the rack1 which is wound with leather so that the tools may be rapidly thrown in place without injury4 ,illustration ,illustration3 ,fig4 #gh4 ,showing ,successive ,steps in ,turning on ,automatic ,pinion ,making ,machine4 ,stock advanced4 ,first collet driven4 ,second collet driven4 ,third collet driven4 ,shoulder turned4 ,first sides faced4 ,second sides faced4 ,pivots turned4 ,pivots burnished4 ,cut off4 ,if a plain1 straight piece of work is to be turned1 the tool is adjusted in the handle so that the work will be of the proper diameter when the round parts of the handle come in contact with the perpendicular part of the knees or rest2 and while the handle is thus held and moved gently along in the corners of the knees1 with the tool sliding on the ,t-rest1 the work is easily turned perfectly parallel1 smooth and true4 ,sometimes a roughing cut is taken by holding the bar loosely and then a finishing cut is made with the same tool by holding it firmly in place4 ,in turning a pinion arbor1 for instance1 the wire having been previously straightened and cut to length and centered1 and the brass collets to make the pinion and to fasten the wheel having been driven on1 one end is held in the lathe by a spring chuck fastened to the spindle of the lathe1 while the other end works in a center in the other head4 ,one turning tool is shaped and adjusted in the handle for the purpose of turning the brass collets for the pinion to the proper diameter1 another turns the sides of the brass work1 while others are adapted for the arbors1 pivots1 and so on1 pins being placed in holes in the ,t-rest to act as stops for the tools4 ,after the brass work has been turned1 the positions of the shoulders of the pivots are marked with a steel gauge1 and by simply turning round the handle of the turning tool till the proper shaped point presents itself1 each operation is accomplished rapidly1 and the cutting is so smooth that even for the pivots all that is necessary to finish them is simply to bring them in contact with a small burnisher4 ,the article is not taken from the lathe during the whole process of turning1 and when completed the centers are broken off1 having been previously marked pretty deep at the proper place with a cutting point4 ,five hundred to #a1bjj arbors per day1 per man1 is the usual output4 ,all the pinions1 arbors1 and barrels--in fact every part of an ,american clock movement that requires turning--were formerly done in this manner1 at long rows of lathes in rooms1 and by workmen set apart for the purpose4 ,but perhaps it may be well to mention that in the machine shops of these factories1 where they make the tools1 the ordinary methods of turning with the common hand tool1 and by the aid of ordinary and special slide rests1 are practiced the same as it is among other machinists4 ,in the large factories automatic turret machines are now coming into use and these are shown in ,figs4 #gg1 #gh and #gi4 ,illustration3 ,fig4 #gi4 ,automatic ,pinion ,drill of the ,davenport ,machine ,company4 ,the lantern pinions of an ,american clock have long been a mystery to those unacquainted with the method of their manufacture1 and the usual accuracy in the position of the small wires or 8rounds10 combined with great cheapness1 has often been a subject of remark4 ,the holes for the wires in these pinions are drilled in a machine constructed as follows3 ,an iron bed with two heads on it1 ,fig4 #hj1 one of which is so constructed that by pulling a lever the spindle has a motion lengthwise as well as the usual circular motion1 and on the point of this spindle1 which is driven at #bb1jjj revolutions1 the drill is fastened that is to bore the holes in the pinions2 the other head has an arbor passing through it with an index plate attached1 having holes in the plate1 and an index finger attached to a strong spring going into the holes1 the same as in a wheel cutting engine2 on this head1 and on the end of it that faces the drill1 there is a frame fastened in which the pinion that is to be bored is placed between centers1 and is carried round with the arbor of the index plate1 in the same manner as a piece of work is carried round in an ordinary lathe by means of a dog1 or carrier2 only in the pinion drilling machine the carrier is so constructed that there is no shake in any way between the pinion and the index arbor4 ,this head is carried on a slide having a motion at right angles to the spindle of the other head1 by which means the pitch diameter of the proposed pinion is adjusted4 ,the head is moved in the slide by an accurately cut screw1 to which a micrometer is attached that enables the workman to make an alteration in the diameter of a pinion as small as the one-thousandth part of an inch4 ,the drill that bores the holes is the ordinary flat-pointed drill1 and has a shoulder on its stem that stops the progress of the drill when it has gone through the first part of the pinion head and nearly through the other4 ,all operators make their own drills and the limits of error are for pitch diameter 4#jjje inch2 error of size of drills 4#jjja4 ,the reader can see that these men must know something of drill making4 ,illustration3 ,fig4 #hj4 ,pinion ,drilling ,machine4 ,the action of the machine is simple4 ,the pinion1 after it has been turned1 pivoted and dogged1 is placed in its position in the machine1 and by pulling a lever1 the drill1 which is running at a speed of about #bb1jjj revolutions a minute1 comes in contact with the brass heads of the pinion and bores the one through and the other nearly through4 ,the lever is then let go1 and a spring pulls the drill back2 the index is turned round a hole1 and another hole bored in the pinion1 and so on till all the holes are bored4 ,an ordinary expert workman1 with a good machine1 will bore about fourteen hundred of medium-sized pinions in a day4 ,the wires or 8rounds0 are cut from drill rod and are put into the holes by hand by girls who become very expert at it4 ,this is called 8filling40 ,we have already stated that the holes are only bored partly through one of the pieces of the brass1 and after the wire has been put in1 the holes are riveted over1 and in this manner the wires are fastened so that they cannot come out4 ,some factories close the holes by a thin brass washer forced on the arbor1 instead of riveting4 ,figs4 #gg1 #gh and #gi show the automatic pinion turning machine and its processes in successive operations4 ,these machines are used by most of the large clock manufacturers of the ,united ,states and some of the ,european concerns also4 ,they are entirely automatic1 will make #a1ejj pinions per day1 as an average1 and one man can run four machines4 ,fig4 #gi shows an automatic pinion drilling machine1 which takes up the work where it is left by the machine shown in ,fig4 #gg4 ,this machine will drill #d1jjj to #e1jjj pinions per day according to the size hole and the number of holes4 ,the operator places the pinions in the special chain shown in the front of the machine1 from which the transport arms carry them to the spindle1 where they are drilled and when completed drop out4 ,one operator can feed three of these machines4 ,,making ,,solid ,,pinions4--,the solid steel pinions are not hardened1 but are made of ,bessemer steel1 which could only be case hardened--a thing hardly ever done4 ,the process of making these pinions is as follows3 ,rods of ,bessemer steel are cut into suitable lengths4 ,the pieces obtained are pointed or centered on both ends4 ,the stock not needed for the pinion head is cut away1 leaving the arbors slightly tapering1 for the purpose of fastening them by this means in a hole on the cutting machine4 ,on the end of the arbor of the index plate are two deep cuts across its center1 and at right angles to each other4 ,these cuts are of the same shape that would be made by a knife edged file4 ,the effect of these cuts is to produce a taper hole in the end of the arbor1 with four sharp corners4 ,into this hole the end of the arbor of the pinion or ratchet that is to be cut is placed1 and a spring center presses on the other end1 and the sharp corners in the hole hold the work firm enough to prevent it from turning round when the teeth are being cut4 ,the marks that are to be seen on the shoulder of the back pivot of the arbor that carries the minute hand of a ,yankee clock is an illustration of this method of holding the pinion when the leaves are being cut1 and no injurious effects arise from it4 ,the convenience the plan affords for fastening work in the engine enables twenty-five hundred of these pinions to be cut in a day1 one at a time4 ,the pinion head is cut subject to the proper dividing plate by a splitting circular saw1 and by a milling tool 7running in oil7 for forming the shape of the leaves1 both of which tools are generally carried on the same arbor1 both being shifted into their proper places by an adjusting attachment4 ,pinion leaves of the better class are generally shaped by two succeeding milling cutters1 the second one of which does the finishing1 obviating any other smoothing4 ,for very cheap work the arbors receive no further finish4 ,the shaping of the pivots1 done by an automatic lathe1 finishes the job4 ,figure #ha shows an automatic pinion cutting machine which has extensive use in clock factories for cutting pinions up to one-half inch diameter and also the smaller wheels4 ,for wheels the work is handled in stacks suited to the traverse of the machine1 the work being treated as if the stacks were long brass pinions4 ,illustration3 ,fig4 #ha4 ,automatic ,wheel and ,pinion ,cutters4 ,wheels are cut in two ways1 on automatic wheel cutters as just described and on engines containing parallel spindles for the cutters1 carried in a yoke which rises and falls1 so that it clears the work while the carriage is returning to the starting point on each trip and engages it on the outward trip4 ,the cutters are about three inches in diameter and rapidly driven2 the first is a saw1 the second a roughing cutter1 and the third a finishing cutter4 ,the carriage is driven by a rack and pinion operated by a crank in the hands of the workman and streams of soda water are used on the cutters and work to carry away the heat1 as brass expands rapidly under heat1 and if the stack were cut dry the cut would get deeper as the cutting proceeded1 owing to the expansion of the brass1 and hence the finished wheel would not be round when cold1 if many teeth were being cut4 ,the stacks of wheels are about four inches in length and the slide thus travels about twenty inches in order to clear the three arbors and engage with the shifter for the index4 ,the last wheel of the stack has a very large burr formed by the cutters as they leave the brass and this wheel is removed from the stack when the arbor is taken out and placed aside to have the burrs removed by rubbing on emery paper4 ,illustration3 ,fig4 #hb4 ,wheel ,cutting ,engine4 ,this is one of the few instances in which automatic machinery has been unable to displace hand labor1 as the work is done so quickly that the time of the attendant would be nearly all taken up in placing and removing the stacks1 and so the feeding is done by him as well4 ,about #ce1jjj wheels per day can be thus cut by one man1 with girls to stack the blanks on the arbors1 and an automatic feed would not release the man from attendance on the machine1 so that the majority of clock wheels are cut to-day as they were forty years ago4 ,still1 some of the factories are adding an automatic feed to the carriage in the belief that the increased evenness of feed will give a more accurately cut wheel1 a proposition which the men most vigorously deny4 ,such a machine1 they say1 to be truly automatic1 must take its stacks of wheels from a magazine and discharge the work when done1 so that one attendant could look after a number of machines4 ,this would result in economy1 as well as accuracy1 but has not been done owing to the great variations in sizes of wheels and numbers of teeth required in clock work4 ,figure #hb shows one of these machines1 a photograph of which was taken especially for us by the courtesy of the ,seth ,thomas ,clock ,company at their factory in ,thomaston1 ,conn4 ,about every ten years some factory decides to try stamping out the teeth of wheels at the same time they are being blanked2 this can1 of course1 be done by simply using a more expensive punch and die1 and at first it looks very attractive2 but it is soon found that the cost of keeping up such expensive dies makes the wheels cost more than if regularly cut and for reasons of economy the return is made to the older and better looking cut wheels4 ,after an acid dip to remove the scale on the sheet brass1 followed by a dip in lacquer1 to prevent further tarnish1 the wheels are riveted on the pinions in a specially constructed jig which keeps them central during the riveting and when finished the truth of every wheel and its pinions and pivots are all tested before they are put into the clocks4 ,the total waste on all processes in making wheels and pinions is from two to five per cent1 so that it will readily be seen that accuracy is demanded by the inspectors4 ,european writers have often found fault with nearly everything else about the ,yankee clock1 but they all unite in agreeing that the cutting and centering of wheels1 pinions and pivots 7and the depthing7 are perfect1 while the clocks of ,germany1 ,france1 ,switzerland and ,england 7particularly ,france7 leave much to be desired in this respect2 and much of the reputation of the ,yankee clock in ,europe comes from the fact that it will run under conditions which would stop those of ,european make4 ,we give herewith a table of clock trains as usually manufactured1 from which lost wheels and pinions may be easily identified by counting the teeth of wheels and pinions which remain in the movement and referring to the table4 ,it will also assist in getting the lengths of missing pendulums by counting the trains and referring to the corresponding length of pendulums4 ,thus1 with #hd teeth in the center wheel1 #gj in the third1 #cj in the escape and #g-leaf pinions1 the clock is #abj beat and requires a pendulum #i4gh inches from the bottom of suspension to the center of the bob4 ,,to ,,calculate ,,clock ,,trains4--,britten gives the following rule3 ,divide the number of pendulum vibrations per hour by twice the number of escape wheel teeth2 the quotient will be the number of turns of escape wheel per hour4 ,multiply this quotient by the number of escape pinion teeth1 and divide the product by the number of third wheel4 ,this quotient will be the number of times the teeth of third wheel pinion must be contained in center wheel4 ,clock ,trains and ,lengths of ,pendulums4 ,vibrations ,length of ,escape of ,pendulum ,pendulum ,wheels ,pinions ,wheel --,min4 in ,inches ---------------------------------------- ------------ #abj #ij #ge #aj #aj #i ,double 99#cj #aef4ef #c legged #abj #ij #ij #aj #i #i ,do4 99#dj #hh4jg #abh #abj #af #cj #fj #ci4ad #aab #aje #ad #cj #fj #ci4ad #if #ij #ab #cj #fj #ci4ad #hj #ge #aj #cj #fj #ci4ad #fd #fj #h #cj #fj #ci4ad #fh #fd #h #cj #fh #cj4di #gj #fd #h #cj #gj #bh4ge #gb #fd #h #cj #gb #bg4ag #ge #fj #h #cb #ge #be4je #gb #fe #h #cb #gh #bc4ae #ge #fd #h #cb #hj #bb4ja #hd #fd #h #cj #hd #ai4ig #hf #fd #h #cj #hf #ai4jf #hh #fd #h #cj #hh #ah4ai #hd #gh #g #bj #hi4a #ag4gb #hj #gb #h #cj #ij #ag4ci #hd #gh #g #ba #ic4f #af4jh #id #fd #h #cj #id #ae4id #hd #gh #h #bh #ie4e #ae4de #ajh #ajj #ab #aj #cb #if #ae4bh #hd #hd #i #h #cj #ih #ad4ff #hd #gh #g #bb #ih #ad4ff #hd #gh #h #bi #ih4i #ad4da #hj #hj #h #cj #ajj #ad4ji #he #gb #h #cb #ajb #ac4ed #hd #gh #h #cj #ajb4d #ac4dd #hd #gh #g #bc #ajb4e #ac4d #aje #ajj #aj #cj #aje #ab4gh #hd #gh #h #ca #aje4h #ab4ei #hd #gh #g #bd #ajg #ab4c #if #gb #h #cj #ajh #ab4jh #hd #gh #h #cb #aji4b #aa4hb #hh #hj #h #cj #aaj #aa4fd #hd #gg #g #be #aaj #aa4fd #hd #gh #g #be #aaa4d #aa4ce #hd #hj #h #cb #aab #aa4bb #hd #gh #h #cc #aab4f #aa4aa #if #gf #h #cj #aad #aj4hb #aae #ajj #aj #cj #aae #aj4fe #hd #gh #g #bf #aae4i #aj4di #if #hj #h #cj #abj #i4gh #hd #gj #g #cj #abj #i4gh #hd #gh #g #bg #abj4c #i4gc #ij #hd #h #ca #abb #i4df #hd #gh #g #bh #abd4h #i4jb #ajj #hj #h #cj #abe #i4ja #ij #hd #h #cb #abf #h4hg #ajj #if #aj #dj #abh #h4ei #hd #gh #g #bi #abi4c #h4db #ajj #gh #h #cb #acj #h4cd #hd #gg #g #cj #acb #h4jh #hd #gh #g #cj #acc4g #g4i #ij #ij #h #cb #ace #g4gc #hd #gh #g #ca #ach4b #g4ch #hd #hj #h #dj #adj #g4ah #abj #ga #h #cb #adb #f4ii #hd #gh #g #cb #adb4f #f4ic #ajj #hg #h #cb #ade #f4fi #hd #gh #g #cc #adg4a #f4e #ajj #if #h #cj #aej #f4bf #hd #gh #g #cd #aea4f #f4a #if #ie #h #cb #aeb #f4ji #hd #gg #g #ce #aed #e4id #ajd #if #h #cj #aef #e4gh #hd #gh #g #ce #aef #e4gh #abj #if #i #h #cj #afj #e4e #hd #gh #g #cf #afj4e #e4dg #hd #gh #g #cg #afd4i #e4ae #acb #ajj #i #h #bg #afe #e4ag #hd #gh #g #ch #afi4d #d4hh #abh #ajb #h #be #agj #d4hg #hd #gh #g #ci #agc4h #d4fe #cf #cf #ce #f #be #age #d4f #hd #gg #g #dj #agf #d4ee #hd #gh #g #dj #agh4c #d4dc #de #cf #cf #f #bj #ahj #d4ce #dg #cf #cf #f #bj #ahh #c4ii 99 ,these are good examples of turret clock trains2 the great wheel 7#abj teeth7 makes in both instances a rotation in three hours4 ,from this wheel the hands are to be driven4 ,this may be done by means of a pinion of #dj gearing with the great wheel1 or a pair of bevel wheels bearing the same proportion to each other 7three to one7 may be used1 the larger one being fixed to the great wheel arbor4 ,the arrangement would in each case depend upon the number and position of the dials4 ,the double three-legged gravity escape wheel moves through #fj at each beat1 and therefore to apply the rule given for calculating clock trains it must be treated as an escape wheel of three teeth4 ,take a pendulum vibrating #e1djj times an hour1 escape wheel of #cj1 pinions of #h1 and third wheel of #gb4 ,then #e1djj #fj #ij4 ,and #ij #h #gb #aj4 ,that is1 the center wheel must have ten times as many teeth as the third wheel pinion1 or ten times #h #hj4 ,the center pinion and great wheel need not be considered in connection with the rest of the train1 but only in relation to the fall of the weight1 or turns of mainspring1 as the case may be4 ,divide the fall of the weight 7or twice the fall1 if double cord and pulley are used7 by the circumference of the barrel 7taken at the center of the cord72 the quotient will be the number of turns the barrel must make4 ,take this number as a divisor1 and the number of turns made by the center wheel during the period from winding to winding as the dividend2 the quotient will be the number of times the center pinion must be contained in the great wheel4 ,or if the numbers of the great wheel and center pinion and the fall of the weight are fixed1 to find the circumference of the barrel1 divide the number of turns of the center wheel by the proportion between the center pinion and the great wheel2 take the quotient obtained as a divisor1 and the fall of the weight as a dividend 7or twice the fall if the pulley is used71 and the quotient will be the circumference of the barrel4 ,to take an ordinary regulator or #h-;day clock as an example--#aib 7number of turns of center pinion in #h days7 #ab 7proportion between center pinion and barrel wheel7 #af 7number of turns of barrel74 ,then if the fall of the cord #dj inches1 #dj #b #af #e1 which would be circumference of barrel at the center of the cord4 ,if the numbers of the wheels are given1 the vibrations per hour of the pendulum may be obtained by dividing the product of the wheel teeth multiplied together by the product of the pinions multiplied together1 and dividing the quotient by twice the number of escape wheel teeth4 ,the numbers generally used by clock makers for clocks with less than half-second pendulum are center wheel #hd1 gearing with a pinion of #g2 third wheel #gh1 gearing with a pinion of #g4 ,the product obtained by multiplying together the center and third wheels #hd #gh #f1eeb4 ,the two pinions multiplied together #g #g #di4 ,then #f1eeb #di #acc4g4 ,so that for every turn of the center wheel the escape pinion turns #acc4g times4 ,or #acc4g #fj #b4bbi1 which is the number of turns in a minute of the escape pinion4 ,the length of the pendulum1 and therefore the number of escape wheel teeth1 in clocks of this class is generally decided with reference to the room to be had in the clock case1 with this restriction1 the escape wheel should not have less than #bj nor more than #dj teeth1 or the performance will not be satisfactory4 ,the length of the pendulum for all escape wheels within this limit is given in the preceding table4 ,the length there stated is of course the theoretical length1 and the ready rule adopted by clockmakers is to measure from the center arbor to the bottom of the inside of the case1 in order to ascertain the greatest length of pendulum which can be used4 ,for instance1 if from the center arbor to the bottom of the case is #aj inches1 they would decide to use a #aj-;inch pendulum1 and cut the escape wheel accordingly with the number of teeth required as shown in the table4 ,but they would make the pendulum rod of such a length as just to clear the bottom of the case when the pendulum was fixed in the clock4 ,in the clocks just referred to the barrel or first wheel has #if teeth1 and gears with a pinion of eight4 ,month clocks have an intermediate wheel and pinion between the great and center wheels4 ,this extra wheel and pinion must have a proportion to each other of #d to #a to enable the #h-;day clock to go #cb days from winding to winding4 ,the weight will have to be four times as heavy1 plus the extra friction1 or if the same weight is used there must be a proportionately longer fall4 ,six-months clock have two extra wheels and pinions between the great and center wheels1 one pair having a proportion of #d to #a and the other of #f to #a4 ,but there is an enormous amount of extra friction generated in these clocks1 and they are not to be recommended4 ,the pivot holes and all the other holes in the frames1 are punched at one operation after the frames have been blanked and flattened4 ,they are placed in the press1 and a large die having punches in it of the proper size and in the right position for the holes1 comes down on the frame and makes the holes with great rapidity and accuracy4 ,these holes are finished afterwards by a broach4 ,in some kinds of clocks1 where some of the pivot holes are very small1 the small holes are simply marked with a sharp point in the die1 and afterwards drilled by small vertical drills4 ,these machines are very convenient for boring a number of holes rapidly4 ,the drill is rotated with great speed1 and a jig or plate on which the work rests is moved upwards towards the drill by a movement of the operator's foot4 ,all the boring1 countersinking1 etc41 in ,american clocks1 is done through the agency of these drills4 ,bending the small wires for the locking work1 the pendulum ball1 etc41 is rapidly effected by forming4 ,as no objectionable marks have been made on the surface of either the thick or smaller wires during any process of construction1 all that is necessary to finish the iron work is simply to clean it well1 which is done in a very effective manner by placing a quantity of work in a revolving tumbling box1 which is simply a barrel containing a quantity of sawdust4 ,milling the winding squares on barrel arbors is an ingenious operation4 ,the machine for milling squares and similar work is made on the principle of a wheel cutting engine4 ,the work is held in a frame1 attached to which is a small index plate1 like that of a cutting engine4 ,in the machine two large mills or cutters1 with teeth in them like a file1 are running1 and the part to be squared is moved in between the revolving cutters1 which operation immediately forms two sides of the square4 ,the work is then drawn back1 and the index turned round1 and in a like manner the other two sides of the square are formed4 ,the cutting sides of the mills are a little bevelled1 so that they will produce a slight taper on the squares4 ,winding keys have shown great improvements4 ,some manufacturers originally used cast iron ones1 but the squares were never good in them1 and brass ones were adopted4 ,at first the squares were made by first drilling a hole and driving a square punch in with a hammer2 and to make the squares in eighteen hundred keys by this method was considered a good day's work4 ,restless ,yankee ingenuity1 however1 has contrived a device by which twenty or twenty-five thousand squares can be made in a day1 while at the same time they are better and straighter squares than those by the old method2 but we are not at liberty to describe the process at present1 but only to state that it is done by what machinists call drilling a square hole4 ,pendulum rods are made from soft iron wire1 and the springs on the ends rolled out by rollers4 ,two operations are necessary4 ,the first roughs the spring out on rollers of eccentric shape1 and the spring is afterwards finished on plain smooth rollers4 ,the pendulum balls in the best clocks are made of lead1 on account of its weight1 and cast in an iron mold in the same manner as lead bullets1 at the rate of about eighteen hundred a day4 ,a movable mandrel is placed in the mold to produce the hole that is in the center of the ball4 ,the balls are afterwards covered with a shell of brass1 polished with a bloodstone burnisher4 ,the various cocks used in these clocks are all struck up from sheet brass1 and the pins in the wheels in the striking part are all swedged into their shape from plain wire4 ,the hands are die struck out of sheet steel1 and afterwards polished on emery belts1 and blued in a furnace4 ,all the little pieces of these clocks are riveted together by hand1 and the different parts of the movement1 when complete1 are put together by workmen continually employed in that department4 ,although the greatest vigilance is used in constructing the different parts to see that they are perfect1 when they come to be put together they are subjected to another examination1 and after the movements are put in the case the clocks are put to the test by actual trial before they are packed ready for the market4 ,as a general rule1 all the different operations are done by workmen employed only at one particular branch2 and in the largest factories from thirty to fifty thousand clocks of all classes may be seen in the various stages of construction4 ,such is a description of the main points in which the manufacture of ,american clock movements differs from those manufactured by other systems4 ,all admit that these clocks perform the duties for which they are designed in an admirable manner1 while they require but little care to manage1 and when out of order but little skill is necessary to repair them4 ,of late years there has been a growing demand for ornamental mantel-piece clocks in metallic cases of superior quality1 and large numbers of these cases of both bronze and gold finish are being manufactured1 which1 for beauty of design and fine execution1 in many instances rival those of ,french production4 ,the shapes of the ordinary ,american movements were1 however1 unsuitable for some patterns of the highest class of cases1 and the full plate1 round movements of the same size as the ,french1 but with improvements in them that in some respects render them more simple than the ,french1 are now manufactured4 ,exactly the same system is employed in the manufacture of the different parts of these clocks that is practiced in making the ordinary ,american movements4 ,,chapter ,,xv4 ,,springs1 ,,weights ,,and ,,power4 ,we see by the preceding calculations that there is one definite point in the time train of a clock2 the center arbor1 which carries the minute hand1 must revolve once in one hour2 from this point we may vary the train both ways1 toward the escape wheel to suit the length of pendulum which we desire to use1 and toward the barrel to suit the length of time we want the clock to run4 ,the center arbor is therefore generally used as the point at which to begin calculations1 and it is also for this reason that the number of teeth in the center wheel is the starting point in train calculations toward the escape wheel1 while the center pinion is the starting point in calculations of the length of time the weight or spring is to drive the clock4 ,most writers on horology ignore this point1 because it seems self-evident1 but its omission has been the cause of much mystification to so many students that it is better to state it in plain terms1 so that even temporary confusion may be avoided4 ,sometimes there is a second fixed point in a time train2 this occurs only when there is a seconds hand to be provided for2 when this is the case the seconds hand must revolve once every minute4 ,if it is a seconds pendulum the hand is generally carried on the escape wheel and the relation of revolutions between the hour and seconds wheels must then be as one is to sixty4 ,this might be accomplished with a single wheel having sixty times as many teeth as the pinion on the seconds arbor2 but the wheel would take up so much room1 on account of its large circumference1 that the movement would become unwieldy because there would be no room left for the other wheels2 so it is cheaper to make more wheels and pinions and thereby get a smaller clock4 ,now the best practical method of dividing this motion is by giving the wheels and pinions a relative velocity of seven and a half and eight1 because #g4e #h #fj4 ,thus if the center wheel has #hj teeth1 gearing into a pinion of #aj1 the pinion will be driven eight times for each revolution of the center wheel1 while the third wheel1 with #ge teeth1 will drive its pinion of #aj leaves #g4e times1 so that this arbor will go #g4e times eight1 or #fj times as fast as the center wheel4 ,if the clock has no seconds hand this second fixed point is not present in the calculations and other considerations may then govern4 ,these are generally the securing of an even motion1 with teeth of wheels and pinions properly meshing into each other1 without incurring undue expense in manufacture by making too many teeth in the pinions and consequently in the wheels4 ,for these reasons pinions of less than seven or more than ten leaves are rarely used in the common clocks1 although regulators and fine clocks1 where the depthing is important1 frequently have #ab1 #ad or #af leaves in the pinions1 as is also the case with tower clocks1 where the increased size of the movement is not as important as a smoothly running train4 ,clocks without pendulums1 carriage clocks1 locomotive levers and nickel alarms1 also have different trains1 many of which have the six leaf pinion1 with its attendant evils1 in their trains4 ,,weights4--,weights have the great advantage of driving a train with uniform power1 which a spring does not accomplish3 ,they are therefore always used where exactness of time is of more importance than compactness or portability of the clock4 ,in making calculations for a weight movement1 the first consideration is that as the coils of the cord must be side by side upon the barrel and each takes up a definite amount of space1 a thicker movement 7with longer arbors7 will be necessary1 as the barrel must give a sufficient number of turns of the cord to run the clock the desired time and the length of the barrel1 with the wheel and maintaining power all mounted upon the one arbor1 will determine the thickness of the movement4 ,if the clock is to have striking trains their barrels will generally be of more turns and consequently longer than the time barrel and in that case the distance between the plates is governed by the length of the longest barrel and its mechanism4 ,the center wheel1 upon the arbor of which sits the canon pinion with the minute hand1 must1 since the hand has to accomplish its revolution in one hour1 also revolve once in an hour4 ,when1 therefore1 the pinion of the center arbor has #h leaves and the barrel wheel #add1 then the #h pinion leaves1 which makes one revolution per hour1 would require the advancing of #h teeth of the barrel wheel1 which is equal to the eighteenth part of its circumference4 ,but when the eighteenth part in its advancing consumes #a hour1 then the entire barrel wheel will consume #ah hours to accomplish one revolution4 ,if1 now1 #aj coils of the weight cord were laid around the barrel1 the clock would then run #aj #ah #ahj hours1 or #g days1 before it is run down4 ,referring to what was said in a previous chapter on wheels being merely compound levers1 it will be seen that as we gain motion we lose power in the same ratio4 ,we shall also see that by working the rule backwards we may arrive at the amount of force exerted on the pendulum by the pallets4 ,if we multiply the circumference of the escape wheel in inches by the number of its revolutions in one hour we will get the number of inches of motion the escape wheel has in one hour4 ,now if we multiply the weight by the distance the barrel wheel travels in one hour and divide by the first number we shall have the force exerted on the escape wheel4 ,it will be simpler to turn the weight into grains before starting1 as the division is less cumbersome4 ,another way is to find how many times the escape wheel revolves to one turn of the barrel and divide the weight by that number1 which will give the proportion of weight at the escape wheel1 or rather would do so if there were no power lost by friction4 ,it is usual to estimate that three-quarters of the power is used up in frictions of teeth and pivots1 so that the amount actually used for propulsion of the pendulum is very small1 being merely sufficient to overcome the bending moment of the suspension spring and the resistance of the air4 ,it is for this reason that clocks with finely cut trains and jeweled pivots1 thus having little train friction1 will run with very small weights4 ,the writer knows of a ,howard regulator with jeweled pivots and pallets running a #ad-pound pendulum with a five-ounce driving weight4 ,of course this is an extreme instance and was the result of an experiment by an expert watchmaker who wanted to see what he could do in this direction4 ,usually the method adopted to determine the amount of weight that is necessary for a movement is to hang a small tin pail on the weight cord and fill it with shot sufficient to barely make the clock keep time4 ,when this point has been determined1 then weigh the pail of shot and make your driving weight from eight to sixteen ounces heavier4 ,in doing this be sure the clock is in beat and that it is the lack of power which stops the clock2 the latter point can be readily determined by adding or taking out shot from the pail until the amount of weight is determined4 ,the extra weight is then added as a reserve power1 to counteract the increase of friction produced by the thickening of the oil4 ,many clock barrels have spiral grooves turned in them to assist in keeping the coils from riding on each other1 as where such riding occurs the riding coils are farther from the center of the barrel than the others1 which gives them a longer leverage and greater power while they are unwinding1 so that the power thus becomes irregular and affects the rate of the clock1 slowing it if the escapement is dead beat and making it go faster if it is a recoil escapement4 ,clock cords should be attached to the barrel at the end which is the farthest from the pendulum1 so that as they unwind the weight is carried away from the pendulum4 ,this is done to avoid sympathetic vibrations of the weight as it passes the pendulum1 which interfere with the timekeeping when they occur4 ,if the weight cannot be brought far enough away to avoid vibrations a sheet of glass may be drilled at its four corners and fixed with screws to posts placed in the back of the case at the point where vibration occurs1 so that the glass is between the pendulum rod and the weight1 but does not interfere with either4 ,this looks well and cures the trouble4 ,we have1 heretofore1 been speaking of weights which hang directly from the barrel1 as was the case with the older clocks with long cases1 so that the weight had plenty of room to fall4 ,where the cases are too short to allow of this method1 recourse is had to hanging the weight on a pulley and fastening one end of the cord to the seat board4 ,this involves doubling the amount of weight and also taking care that the end of the cord is fastened far enough from the slot through which it unwinds so that the cords will not twist1 as they are likely to do if they are near together and the cord has been twisted too much while putting it on the barrel4 ,twisting weight cords are a frequent source of trouble when new cords have been put on a clock4 ,the pulley is another source of trouble1 especially if wire cords 7picture cords7 or cables are used4 ,wire cable should not be bent in a circle smaller than forty times its diameter if flexibility is to be maintained1 hence pulleys which were all right for gut or silk frequently prove too small when wire is substituted and kinks1 twisted and broken cables frequently result from this cause4 ,this is especially the case with the heavy weight of striking trains of hall and chiming clocks1 where double pulleys are used1 and also leads to trouble by jamming and cutting the cables and dropping of the weights in tower clocks where a new cable of larger size is used to replace an old one which has become unsafe from rust1 or cut by the sheaves4 ,weight cords on the striking side of a clock should always be left long enough so that they will not run down and stop before the time train has stopped4 ,this is particularly the case with the old ,english hall clocks1 as many of them will drop or push their gathering racks free of the gathering pinion under such conditions and then when the clock is wound it will go on striking continuously until the dial is taken off and the rack replaced in mesh with the gathering pinion4 ,as clocks are usually wound at night1 the watchmaker can see the disturbance that would be caused in a house in the 8wee sma' hours0 by such a clock going on a rampage and striking continuously4 ,,oiling ,,cables4--,clock cables1 if of wire and small in size1 should be oiled by dipping in vaseline thinned with benzine of good quality4 ,both benzine and vaseline must be free from acid1 as if the latter is present it will attack the cable4 ,this thinning will permit the vaseline to permeate the entire cable and when the benzine evaporates it will leave a thin film of vaseline over every wire1 thus preventing rust4 ,tower clock cables should be oiled with a good mineral oil1 well soaked into them to prevent rusting4 ,gut clock cords1 when dry and hard1 are best treated with clock oil1 but olive oil or sperm oil will also be found good to soften and preserve them4 ,new cords should always be oiled until they are soft and flexible4 ,if the weight is under ten pounds silk cords are preferable to gut or wire as they are very soft and flexible4 ,in putting on a new cable or weight cord the course of the weight and cord should be closely watched at all points1 to see that they remain free and do not chafe or bind anywhere and also that the coils run evenly and freely1 side by side2 sometimes1 especially with wire1 a new cable gets kinked by riding the first time of winding and is then very difficult to cure of this serious fault4 ,another point to watch is to see that the position of the cord when wound up will not cause an end thrust upon the barrel1 which will interfere with the timekeeping if it is overwound1 so that the weight is jammed against the seatboard2 this frequently happens with careless winding1 if there is no stop work4 ,to determine the lengths of clock cords or weights1 we may have to approach the question from either end4 ,if the clock be brought in without the cords1 we first count the number of turns we can get on the barrel4 ,this may be done by measuring the length of the barrel and dividing it by the thickness of the cord1 if the barrel is smooth1 or by counting the grooves if it be a grooved barrel4 ,next we caliper the diameter and add the thickness of one cord1 which gives us the diameter of the barrel to the center of the cords1 which is the real or working diameter4 ,multiply the distance so found by #c4adaef1 which gives the circumference of the barrel1 or the length of cord for one turn of the barrel4 ,multiply the length of one turn by the number of turns and we have the length of cord on the barrel1 when it is fully wound4 ,if the cord is to be attached to the weight1 measure the distance from the center of barrel to the bottom of the seat board and leave enough for tying4 ,if the weight is on a pulley it will generally require about twelve inches to reach from the barrel through the slot of the seat board1 through the pulley to the point of fastening4 ,to get the fall of the weight1 stand it on the bottom of the case and measure the distance from the top of the point of attachment to the bottom of the seat board4 ,this will generally allow the weight to fall within two inches of the bottom and thus keep the cable tight when the clock runs down2 thus avoiding kinks and over-riding when we wind again after allowing the clock to run down4 ,if the weight has a pulley and double cord1 measure from the top of the pulley to the seatboard1 with the weight on the bottom1 and then double this measurement for the length of the cord4 ,this measure is multiplied by as many times as there are pulleys in the case of additional sheaves4 ,striking trains are frequently run with two coils or layers of cord1 on the barrel1 time trains never have but one4 ,now1 having the greatest available length of cord determined according either of the above conditions1 we can determine the number of turns for which we have room on our barrel and divide the length of cord by the number of turns4 ,this will give us the length of one turn of the cord on our barrel and thus having found the circumference it is easy to find the diameter which we must give our barrel in suiting a movement to given dimensions of the case4 ,this is frequently done where the factory may want a movement to fit a particular style and size of case which has proved popular1 or when a watchmaker desires to make a movement for which he has1 or will buy1 a case already made4 ,as to tower clock cables1 getting the length of cable on the barrel is1 of course1 the same as given above1 but the rest of it is an individual problem in every case1 as cables are led so differently and the length of fall varies so that only the professional tower clock men are fitted to make the measurements for new work and they require no instruction from me4 ,it might be well to add1 however1 that in the tower clocks by far the greater part of the cable is always outside the clock and only the inner end coils and uncoils about the barrel4 ,it is for this reason that the outer ends of the cables are so generally neglected by watchmakers in charge of tower clocks and allowed to cut and rust until they drop their weights4 ,caretakers of tower clocks should remember that the inner ends of cables are always the best ends2 the parts that need watching are those in the sheaves or leading to the sheaves4 ,tower clocks should have the cables marked where to stop to prevent overwinding4 ,in chain drives for the weights of cuckoo and other clocks with exposed weights1 we have generally a steel sprocket wheel with convex guiding surfaces each side of the sprocket and projecting flanges each side of the guides2 one of these flanges is generally the ratchet wheel4 ,the ratchet wheel1 guide1 sprocket1 guide and flange1 form a built-up wheel which is loose on the arbor and is pinned close to the great wheel1 which is driven by a click on the wheel working into the ratchet of the drive4 ,it must be loose on the arbor1 because the clock is wound by pulling the sprocket and ratchet backward by means of the chain until the weight is raised clear up to the seat board4 ,there are no squares on the arbors1 which have ordinary pivots at both ends1 and the great wheel is fast on the arbor4 ,the diameter of the convex portion of the wheel each side of the sprocket is the diameter of the barrel1 and the chain should fit so that alternate links will fit nicely in the teeth of the sprocket2 where this is not the case they will miss a link occasionally and the weight will then fall until the chain catches again1 when it will stop with a jerk2 bent or jammed links in the chain will do the same thing4 ,sometimes a light chain on a heavy weight will stretch or spread the links enough to make their action faulty4 ,if examination shows a tendency to open the links1 they should be soldered2 if they are stretching1 a heavier chain of correct lengths of links should be substituted4 ,twisted chains are another characteristic fault and are usually the result of bent or jammed links4 ,a close examination of such a chain will generally reveal several links in succession which are not quite flat and careful straightening of these links will generally cure the tendency to twist4 ,,mainsprings ,,for ,,clocks4--,there are many points of difference between mainsprings for clocks and those for watches4 ,they differ in size1 strength1 number of coils and in their effect on the rates of the clock4 ,watch springs are practically all for #cj-;hour lever escapements1 with a few cylinder1 duplex and chronometer escapements4 ,if a fusee watch happens into a shop nowadays it is so rare as to be a curiosity worth stopping work to look at4 ,the clocks range all the way from #cj hours to #djj days in length of time between windings and include lever1 cylinder1 duplex1 dead beat1 half dead beat1 recoil and other escapements4 ,furthermore some of these1 even of the same form of escapements1 will vary so in weight and the consequent influence of the spring that what will pass in one case will give a wildly erratic rate in another instance4 ,many of the small ,french clocks have such small and light pendulums that very nice management of the stop works is necessary to prevent the clock from gaining wildly when wound or stopping altogether when half run down4 ,nothing will cause a clock with a cylinder escapement to vary in time more than a set or gummy mainspring1 for it will gain time when first wound and lose when half run down1 or when there is but little power on the train4 ,in such a case examine the mainspring and see that it is neither gummy nor set4 ,if it is set1 put in a new spring and you can probably bring it to time4 ,with a clock it depends entirely on the kind of escapement that it contains1 whether it runs faster or slower1 with a stronger spring2 if you put a stronger mainspring in a clock that contains a recoil escapement the clock will gain time1 because the extra power1 transmitted to the pallets will cause the pendulum to take a shorter arc1 therefore gain time1 where the reverse occurs in the dead-beat escapement4 ,a stronger spring will cause the dead-beat pendulum to take a longer arc and therefore lose time4 ,if a pendulum is short and light these effects will be much greater than with a long and heavy pendulum4 ,at all clock factories they test the mainsprings for power and to see that they unwind evenly2 those that do are marked ,no4 #a1 and those that do not are called 8seconds40 ,the seconds are used only for the striking side of the clocks1 while the perfect ones are used for the running1 or time side4 ,sometimes1 however1 a seconds' spring will be put on the time side and will cause the clock to vary in a most erratic way4 ,this changing of springs is very often done by careless or ignorant workmen in cleaning and then they cannot locate the trouble4 ,all mainsprings for both clocks and watches should be smooth and well polished4 ,proper attention to this one item will save many dollars' worth of time in examining movements to try to detect the cause of variations4 ,a rough mainspring 7that is1 an emery finished mainspring7 will lose one-third of its power from coil friction1 and in certain instances even one-half4 ,the deceptive feature about this to the watchmaker is that the clock will take a good motion with a rough spring fully found1 but will fall off when partly unwound1 and the consequence is that he finds a good motion when the spring is put in and wound1 and he afterward neglects to examine the spring when he examines the rate as faulty4 ,the best springs are cheap enough1 so that only the best quality should be used1 as it is easy for a watchmaker to lose three or four dollars' worth of time looking for faults in the escapement1 train and everywhere else1 except the barrel1 when he has inserted a rough1 thick1 poorly made spring4 ,the most that he can save on the cheaper qualities of springs is about five cents per spring and we will ask any watchmaker how long it would take to lose five cents in examination of a movement to see what is defective4 ,here is something which you can try yourself at the bench4 ,take a rough watch mainspring2 coil it small enough to be grasped in the hand and then press on the spring evenly and steadily4 ,you will find it difficult to make the coils slide on one another as the inner coils get smaller2 they will stick together and give way by jerks4 ,now open your hand slowly and you will feel the spring uncoiling in an abrupt1 jerky way1 sometimes exerting very little pressure on the hand1 at other times a great deal4 ,a dirty1 gummy spring will do the same thing4 ,now take a clean1 well polished spring and try it the same way2 notice how much more even and steady is the pressure required to move the coils upon each other1 either in compressing or expanding4 ,now oil the well polished spring and try it again4 ,you will find you now have something that is instantly responding1 evenly and smoothly1 to every variation of pressure4 ,you can also compress the spring two or three turns farther with the same force4 ,this is what goes on in the barrel of every clock or watch2 you have merely been using your hand as a barrel and feeling the action of the springs4 ,now a well finished mainspring that is gummy is as irregular in its action as the worst of the springs described above1 yet very few watchmakers will take out the springs of a clock if they are in a barrel4 ,one of them once said to me1 8,why1 who ever takes out springs8 ,i'll bet ,i clean a hundred clocks before ,i take out the springs of one of them60 ,yet this same man had then a clock which had come back to him and which was the cause of the conversation4 ,there must be in this country over #be1jjj fine ,french clocks in expensive marble or onyx cases1 which were given as wedding presents to their owners1 and which have never run properly and in many instances cannot be made to run by the watchmakers to whom they were taken when they stopped4 ,let me give the history of one of them4 ,it was an eight-day ,french marble clock which cost #be 7wholesale7 in ,st4 ,louis and was given as a wedding present4 ,three months later it stopped and was taken to a watchmaker well known to be skillful and who had a fine run of expensive watches constantly coming to him4 ,he cleaned the clock1 took it home and it ran three hours6 ,it came back to him three times2 during these periods he went over the movement repeatedly2 every wheel was tested in a depthing tool and found to be round3 all the teeth were examined separately under a glass and found to be perfect2 the pinions were subjected to the same careful scrutiny2 the depthings were tried with each wheel and pinion separately2 the pivots were tested and found to be right2 the movement was put in its case and examined there2 it would run all right on the watchmaker's bench1 but not in the home of its owner4 ,it would stop every time it was moved in dusting the mantel4 ,he became disgusted and took the clock to another watchmaker1 a railroad time inspector2 same results4 ,in this way the clock moved about for three years2 whenever the owner heard of a man who was accounted more than ordinarily skillful he took him the clock and watched him 8fall down0 on it4 ,finally it came into the hands of an ex-president of the ,american ,horological ,society4 ,he made it run three weeks4 ,when he found the clock had stopped again he refused pay for it4 ,three months later he called and got the clock1 kept it for three weeks1 brought it back without explanation and lo1 the clock ran6 ,it would even run considerably out of beat6 ,when asked what he had done to the clock1 he merely laughed and said 8,wait40 ,a year later the clock was still going satisfactorily and he explained4 8,that was the first time ,i ever got anything ,i couldn't fix and it made me ashamed4 ,i kept thinking it over4 ,finally one night in bed ,i got to considering why a clock wouldn't run when there was nothing the matter with it4 ,the only reason ,i could see was lack of power4 ,next morning ,i got the clock and put in new mainsprings1 the best ,i could find4 ,the clock was cured6 ,none of these other men who had the clock took out the springs4 ,they came to me all gummed up1 while the rest of the clock was clean1 bright and in perfect order4 ,i cleaned the springs and returned the clock2 it ran three weeks4 ,when ,i took it back ,i put in stronger springs1 because ,i found them a little soft on testing them4 ,if any of your friends have ,french clocks that won't go1 send them to me40 ,three-quarters of the trouble with ,french clocks is in the spring box2 mainspring too weak1 gummy or set2 stop works not properly adjusted1 or left off by some numskull who thought he could make the clock keep time without it when the maker couldn't2 mainspring rough1 so that it uncoils by jerks2 spring too strong1 so that the small and light pendulum cannot control it4 ,these will account for far more cases than the 8flat wheel0 story that so often comes to the front to account for a failure on the part of the workman4 ,of course he must say something to his boss to account for his failure and the 8wheels out of round0 and 8the faulty depthing0 have been standard excuses for ,french clocks for a century4 ,of course they do occur1 but not nearly as often as they are credited with1 and even then such a clock may be made to perform creditably if the springs are right4 ,another source of trouble is buckled springs1 caused by some workman taking them out or putting them in the barrel without a mainspring winder4 ,there are many men who will tell you that they never use a winder2 they can put any spring in without it4 ,perhaps they can1 but there comes a day when they get a soft spring that is too wide for this treatment and they stretch one side of it1 or bend1 or kink it1 and then comes coil friction with its attendant evils4 ,these may not show with a heavy pendulum1 but they are certain to do so if it happens to be an eight-day movement with light pendulum or balance1 and this is particularly true of a cylinder4 ,all springs should be cleaned by soaking in benzine or gasoline and rubbing with a rag until all the gum is off them before they are oiled4 ,heavy springs may be wiped by wrapping one or two turns of a rag around them and pushing it around the coils4 ,the spring should be well cleaned and dried before oiling4 ,a quick way of cleaning is to wind the springs clear up2 stick a peg in the escape wheel2 remove the pallet fork2 plunge the whole movement into a pail of gasoline large enough to cover it2 let it stand until the gasoline has soaked into the barrels2 remove the peg and let the trains run down4 ,the coils of the spring will scrub each other in unwinding2 the pivots will clean the pivot holes and the teeth of wheels and pinions will clean each other4 ,then take the clock apart for repairs4 ,springs which are not in barrels should be wound up and spring clamps put on them before taking down the clock4 ,about six sizes of these clamps 7from #b inches to inch7 are sufficient for ordinary work4 ,rancid oil is also the cause of many 8come-backs40 ,workmen will buy a large bottle of good oil and leave it standing uncorked1 or in the sun1 or too near a stove in winter time1 until it spoils4 ,used in this condition it will dry or gum in a month or two and the clock comes back1 if the owner is particular2 if not1 he simply tells his friends that you can't fix a clock and they had better go elsewhere with their watches4 ,for clock mainsprings1 clock oil1 such as you buy from material dealers1 is recommended provided it is intended for ,french mainsprings4 ,if the lubricant is needed for coarse ,american springs1 mix some vaseline with refined benzine and put it on liberally4 ,the benzine will dissolve the vaseline and will help to convey the lubricant all over the spring1 leaving no part untouched4 ,the liquid will then evaporate1 leaving a thin coating of vaseline on the spring4 ,it is best to let springs down1 with a key made for the purpose4 ,it is a key with a large1 round1 wooden handle1 which fills the hand of the watchmaker when he grasps it4 ,placing the key on the arbor square1 with the movement held securely in a vise1 wind the spring until you can release the click of the ratchet with a screwdriver1 wire or other tool2 hold the click free of the ratchet and let the handle of the key turn slowly round in the hand until the spring is down4 ,be careful not to release the pressure on the key too much1 or it will get away from you if the spring is strong1 and will damage the movement4 ,this is why the handle is made so large1 so that you can hold a strong spring4 ,it is of great importance1 if we wish to avoid variable coil friction1 that the spring should wind1 from the very starting1 concentrically2 i4 e41 that the coils should commence to wind in regular spirals1 equidistant from each other1 around the arbor4 ,in very many cases we find1 when we commence to wind a spring1 that the innermost coil bulges out on one side1 causing1 from the very beginning1 a greater friction of the coils on that side1 the outer ones pressing hard against it as you continue to wind1 while on the outer side of the arbor they are separated from each other by quite a little space between them1 and that this bulge in the first coil is overcome and becomes concentric to the arbor only after the spring is more than half way wound up4 ,this necessarily produces greater and more variable coil friction4 ,when a spring is put into the barrel the innermost coil should come to the center around the arbor by a gradual sweep1 starting from at least one turn around away from the other coils4 ,instead of that1 we more often find it laying close to the outer coils to the very end1 and ending abruptly in the curl in the soft end that is to be next the arbor4 ,when this is the case in a spring of uniform thickness throughout1 it is mainly due to the manner of first winding it from its straight into a spiral form4 ,to obviate it1 ,i generally wind the first coils1 say two or three1 on a center in the winder1 a trifle smaller than the regular one1 which is to be of the same diameter of the arbor center in the barrel4 ,you will find that the substitution of the regular center1 afterwards1 will not undo the extra bending thus produced on the inner coils1 and that the spring will abut by a more gradual sweep at the center1 and wind more concentrically4 ,the form of spring formerly used with a fusee in ,english carriage clocks and marine chronometers is a spring tapering slightly in thickness from the inner end for a distance of two full coils1 the thickness increasing as we move away from the end1 then continuing of uniform thickness until within about a coil and a half from the other end1 when it again increases in thickness by a gradual taper4 ,the increase in the thickness towards the outer end will cause it to cling more firmly to the wall of the barrel4 ,the best substitute for this taper on the outside is a brace added to some of the springs immediately back of the hole4 ,with this brace1 and the core of the winding arbor cut spirally1 excellent results are obtained with a spring of uniform thickness throughout its entire length4 ,something1 too1 can be done to improve the action of a spring that has no brace1 by hooking it properly to the barrel4 ,the hole in the spring on the outside should never be made close to the end2 on the contrary1 there should be from a half to three-quarters of an inch left beyond the hole4 ,this end portion will act as a brace4 ,when the spring is down1 the innermost coil of it should form a gradual spiral curve towards the center1 so as to meet the arbor without forcing it to one side or the other4 ,this curve can be improved upon1 if not correct1 with suitably shaped pliers2 or it can be approximated by winding the innermost coils first on an arbor a little smaller in diameter than the barrel arbor itself4 ,another and very important factor in the development of the force of the spring is the proper length and thickness of it4 ,for any diameter of barrel there is but one length and one thickness of spring that will give the maximum number of turns to wind4 ,this is conditioned by the fact that the volume which the spring occupies when it is down must not be greater nor less than the volume of the empty space around the arbor into which it is to be wound1 so that the outermost coil of the spring when fully wound will occupy the same place which the innermost occupies when it is down4 ,in a barrel1 the diameter of whose arbor is one-third that of the barrel1 the condition is fulfilled when the measure across the coils of the spring as it lays against the wall of the barrel1 is #j4ci of the empty space1 or1 taking the diameter of the barrel as a comparison1 #j4abc of the latter2 in other words1 nearly one-eighth of the diameter of the barrel4 ,this is the width that will give the greatest number of turns to wind1 whatever may be the length or thickness of any spring4 ,if now we desire a spring to wind a given number of turns1 there is but one thickness and one length of it that will permit it to do so4 ,the thickness remaining the same1 if we make the spring longer or shorter1 we reduce the number of turns it will wind2 more rapidly by making it shorter1 less so by making it longer4 ,it is therefore not only useless1 but detrimental1 to put into a barrel a greater number of coils1 or turns1 than are necessary1 not only because it will reduce the number of turns the barrel will wind1 but it will produce greater coil friction by filling up the space with more coils than are necessary4 ,a mainspring in the act of uncoiling in its barrel always gives a number of turns equal to the difference between the number of coils in the up and the down positions4 ,thus1 if #ag be the number of coils when the spring is run down1 and #be the number when against the arbor1 the number of turns in uncoiling will be #h1 or the difference between #ag and #be4 ,the cause of breakage is usually1 that the inner coils are put to the greatest strain1 and then the slightest flaw in the steel1 a speck of rust1 grooves cut in the edges of the spring by allowing a screwdriver to slip over them1 or an unequal effect of change of temperature1 causes the fracture1 and leaves the spring free to uncoil itself with very great rapidity4 ,now this sudden uncoiling means that the whole energy of the spring is expended on the barrel in a very small fraction of a second4 ,in reality the spring strikes the inner side of the rim of the barrel1 a violent blow in the direction the spring is turning1 that is1 backwards2 this is due to the mainspring's inertia and its very high mean velocity4 ,the velocity is nothing at the outer end1 where the spring is fixed1 but rises to the maximum at the point of fracture1 and the kinetic energy at various points of the spring could no doubt be calculated mathematically or otherwise4 ,for instance1 take a going barrel spring of eight and a half turns1 breaking close up to the center while fully wound4 ,a point in the spring at the fracture makes eight turns in the opposite direction to which it was wound1 a point at the middle four turns1 and a point at the outer end nothing1 an effect similar to the whole mass of the spring making four turns backwards4 ,at its greatest velocity it is suddenly stopped by the barrel1 wheel teeth engaging its pinion2 this stoppage or collision is what breaks center pinions1 third pivots1 wheel teeth1 etc41 unless their elasticity1 or some interposed contrivance1 can safely absorb the stored-up energy of the mainspring1 the spring being1 as every one knows1 the heaviest moving part in an ordinary clock1 except where the barrel is exceptionally massive4 ,,stop ,,works4--,stop works are devices that are but little understood by the majority of workmen in the trade4 ,they are added to a movement for either one or both of two distinct purposes3 ,first1 as a safety device1 to prevent injury to the escape wheel from over winding1 or to prevent undue force coming on the pendulum by jamming the weight against the top of the seat board and causing a variation in time in a fine clock2 or1 second1 to use as a compromise by utilizing only the middle portion of a long and powerful spring1 which varies too much in the amount of its power in the up and down positions to get a good rate on the clock if all the force of the spring were utilized in driving the movement4 ,with weight clocks1 the stop work is a safety device and should always be set so that it will stop the winding when the barrel is filled by the cord2 consequently the way to set them is to wind until the barrel is barely full and set the stops with the fingers locked so as to prevent any further action of the arbor in the direction of the winding and the cord should then be long enough to permit the weight to be free4 ,then unwind until within half a coil of the knot in the cord where it is attached to the barrel and see that the weight is also free at the bottom of the case1 when the stops again come into action4 ,this will allow the full capacity of the barrel to be used4 ,when stop work is found on a spring barrel1 it may be taken for granted that the barrel contains more spring than is being wound and unwound in the operation of the clock and it then becomes important to know how many coils are thus held under tension1 so that we may put it back correctly after cleaning4 ,wind up the spring and then let it slowly down with the key until the stop work is locked1 counting the number of turns1 and writing it down4 ,then hold the spring with the letting down key and take a screw driver and remove the stop from the plate2 then count the number of turns until the spring is down and also write that down4 ,then take out the spring and clean it4 ,you may find such a spring will give seventeen turns in the barrel without the stop work on1 while it will give but ten with the stop work2 also that the arbor turned four revolutions after you removed the stop4 ,then the spring ran the clock from the fourth to the fourteenth turns and there were four coils unused around the arbor1 ten to run the clock and three unused at the outer end around the barrel4 ,this would indicate a short and light pendulum or balance1 which is very apt to be erratic under variations of power1 and if the rate was complained of by the customer you can look for trouble unless the best adjustment of the spring is secured4 ,put the spring back by winding the four turns and putting on the stop work in the locked position2 then wind4 ,if the clock gains when up and loses when down1 shift the stop works half a turn backwards or forwards and note the result1 making changes of the stop until you have found the point at which there is the least variation of power in the up and down positions4 ,if the variation is still too great a thinner spring must be substituted4 ,there are several kinds of stop work1 the most common being what is known as the ,geneva stop1 a ,maltese cross and a finger such as is commonly seen on watches4 ,for watches they have five notches1 but for clocks they are made with a greater number of notches1 according to the number of turns desired for the arbor4 ,the finger piece is mounted on a square on the barrel arbor and the star wheel on the stud on the plate4 ,in setting them see that the finger is in line with the center of the star wheel when the stop is locked1 or they will not work smoothly4 ,there is another kind of stopwork which is used in some ,american clocks1 and as there is no friction with it1 and no fear of sticking1 nor any doubt of the certainty of its action1 it is perhaps the most suitable for regulators and other fine clocks which have many turns of the barrel in winding4 ,this stop is simple and sure4 ,it consists of a pair of wheels of any numbers with the ratio of odd numbers as #g and #f1 #i and #aj1 #ae and #af1 #cj and #cb1 #de and #dh1 etc42 the smaller wheel is squared on the barrel arbor and the larger mounted on a stud on the plate4 ,these wheels are better if made with a larger number of teeth4 ,on each wheel a finger is planted1 projecting a little beyond the outsides of the wheel teeth1 so that when the fingers meet they will butt securely4 ,the meeting of these fingers cannot take place at every revolution because of the difference in the numbers of the teeth of the wheels2 they will pass without touching every time till the cycle of turns is completed1 as one wheel goes round say sixteen times while the other goes fifteen1 and when this occurs the fingers will engage and so stop further winding4 ,when the clock has run down sixteen turns of the barrel the fingers will again meet on the opposite side1 and so the barrel will be allowed to turn backwards and forwards for sixteen revolutions1 being stopped by the fingers at each extreme4 ,when in action the fingers may butt either at a right or an obtuse angle1 only not too obtuse1 as this would put a strain on1 tending to force the wheels apart4 ,if preferred the fingers may be made of steel1 but this is not necessary4 ,illustration3 ,fig4 #hc4 ,,maintaining ,,powers4--,astronomical clocks1 watchmaker's regulators and tower clocks are1 or at least should be1 fitted with maintaining power4 ,a good tower clock should not vary in its rate more than five to ten seconds a week4 ,many of them1 when favorably situated and carefully tended1 do not vary over five to ten seconds per month4 ,it requires from five to thirty minutes to wind the time trains of these clocks and the reader can easily see where the rate would go if the power were removed from the pendulum for that length of time2 hence a maintaining power that will keep nearly the same pressure on the escape wheel as the weight does1 is a necessity4 ,astronomical clocks and fine regulators have so little train friction1 especially if jeweled1 that when the barrel is turned backwards in winding the friction between the barrel head and the great wheel is sufficient to stop the train1 or even run it backwards1 injuring the escape wheel and1 of course1 destroying the rate of the clock2 therefore they are provided with a device that will prevent such an occurrence4 ,ordinary clocks do not have the maintaining power because only the barrel arbor is reversed in winding1 and that reversal is never for more than half a turn at a time1 as the power is thrown back on the train every time the winder lets go of the key to turn his hand over for another grip4 ,illustration3 ,fig4 #hd4 ,illustration3 ,fig4 #he4 ,figs4 #hc1 #hd and #he show the various forms of maintaining powers1 which differ only in their mechanical details4 ,in all of them the maintaining power consists of two ratchet wheels1 two clicks and either one or two springs2 the springs vary in shape according to whether the great wheel is provided with spokes or left with a web4 ,if the great wheel has spokes the springs are attached on the outside of the large ratchet wheel so that they will press on opposite spokes of the great wheel and are either straight1 curved or coiled1 according to the taste of the maker of the clock and the amount of room4 ,if made with a web a circular recess is cut in the great wheel1 see ,fig4 #hc1 wide and deep enough for a single coil of spring wire which has its ends bent at right angles to the plane of the spring and one end slipped in a hole of the ratchet and the other in a similar hole in the recess of the great wheel4 ,a circular slot is cut at some portion of the recess in the great wheel where it will not interfere with the spring and a screw in the ratchet works back and forth in this slot1 limiting the action of the spring4 ,stops are also provided for the spokes of the great wheel in the case of straight1 curved or coiled springs1 ,figs4 #hd and #he4 ,these stops are set so as to give an angular movement of two or three teeth of the great wheel in the case of tower clocks and from six to eight teeth in a regulator4 ,the springs should exert a pressure on the great wheel of just a little less than the pull of the weight on the barrel2 they will then be compressed all the time the weight is in action1 and the stops will then transmit the power from the large ratchet to the great wheel1 which drives the train4 ,both the great wheel and the large ratchet wheel are loose on the arbor1 being pinned close to the barrel1 but free to revolve4 ,a smaller ratchet1 having its teeth cut in the reverse direction from those of the larger one1 is fast to the end of the barrel4 ,a click1 called the winding click1 on the larger ratchet acts in the teeth of the smaller one during the winding1 holding the two ratchets together at all other times4 ,a longer click1 called the detent click1 is pivoted to the clock plate1 and drags idly over the teeth of the larger ratchet while the clock is being driven by the weight and the maintaining springs are compressed4 ,when the power is taken off by the reversal of the barrel in winding1 the friction between the sides of the two ratchets and great wheel would cause them to also turn backward1 if it were not for this detent click1 with its end fast to the plate1 which drops into the teeth of the large ratchet and prevents it from turning backward4 ,we now have the large ratchet held motionless by the detent click on the clock plate and the compressed springs which are carried between the large ratchet and the great wheel will then begin to expand1 driving the loose great wheel until their force has been expended1 or until winding is completed1 when they will again be compressed by the pull of the weight4 ,in some tower clocks curved pins are fixed to opposite spokes of the great wheel and coiled springs are wound around the pins1 ,fig4 #he2 eyes in the large ratchet engage the outer ends of the pins and compress the springs4 ,illustration3 ,fig4 #hf4 ,the clicks for maintaining powers should not be short1 and the planting should be done so that lines drawn from the barrel center to the click points and from the click centers to the points1 will form an obtuse angle1 like ,b1 ,fig4 #hf1 giving a tendency for the ratchet tooth to draw the click towards the barrel center4 ,the clicks should be nicely formed1 hardened and tempered and polished all over with emery4 ,long1 thin springs will be needed to keep the winding clicks up to the ratchet teeth4 ,the ratchet wheel must run freely on the barrel arbor1 being carried round by the clicks while the clock is going1 and standing still while the weight is being wound up4 ,it is retained at this time by a long detent click mounted on an arbor having its pivots fitted to holes in the clock frame4 ,the same remark as to planting applies to this click as well as the others1 and to all clicks having similar objects2 but as this click has its own weight to cause it to fall no spring is required4 ,to prevent it lying heavily on the wheel1 causing wear1 friction and a diminution of driving power1 it is as well to have it made light4 ,there is no absolute utility in fixing the click to its collet with screws1 but if done1 it can be taken off to be polished1 and the appearance will be more workmanlike4 ,this click should have its point hardened and tempered1 as there is considerable wear on it4 ,illustration3 ,fig4 #hg4 ,if the great wheel has spokes the best form for the two springs for keeping the train going whilst being wound is that of the letter ,u1 as shown to the left of ,fig4 #hd1 one end enlarged for the screw and steady pin and the blade tapering all along towards the end which is free4 ,the springs may be made straight and bent to the form while soft1 then hardened and tempered to a full blue4 ,they are best when as large as the space between two arms of the main wheel will allow4 ,when screwed on the large ratchet the backs of both should bear exactly against the respective arms of the mainwheel1 and a pair of pins is put in the ratchet1 so that any opposite pair of the mainwheel arms may rest upon them when the springs are set up by the clock weight4 ,the strength of the springs can be adjusted by trial1 reducing them till the weight of the clock sets them up easily to the banking pins4 ,there are two methods of keeping the loose wheels against the end of the barrel1 while allowing them to turn freely during winding2 one is a sliding plate with a keyhole slot1 ,fig4 #hg1 to slip in a groove on the arbor1 as is generally adopted in such house clocks as have fuzees1 as well as on the barrels of old-fashioned weight clocks2 the other is a collet exactly the same as on watch fuzees4 ,they are both sufficiently effective1 but perhaps the latter is the best of the two1 because the collet may be fitted on the arbor with a pipe1 and being turned true on the broad inside face1 gives a larger and steadier surface for the mainwheel to work against1 whereas the former only has a small bearing on the shoulder of the small groove in the arbor1 which fitting is liable to wear and allow the main and the other loose wheel to wobble sideways1 displacing the contact with the detent click and causing the mainwheel to touch the collet of the center wheel if very near together2 so1 on the whole1 a collet1 as on a watch fuzee1 seems the better arrangement1 where there is plenty of room for it on the arbor4 ,there is an older form of maintaining power which is sometimes met with in tower clocks and which is sometimes imitated on a small scale by jewelers who are using a cheap regulator and wish to add a maintaining power where there is no room between the barrel and plates for the ratchets and great wheel4 ,the maintaining power1 ,fig4 #hh1 consists of a shaft1 ,a1 a straight lever1 ,b1 a segment of a pinion1 ,c1 a curved1 double lever1 ,d1 a weight1 ,e4 ,the shaft1 ,a1 slides endwise to engage the teeth of the pinion segment with the teeth of the great wheel4 ,no4 #b1 the straight lever has a handle at both ends to assist in throwing the pinion out or in and a shield at the outer end to cover the end of the winding shaft1 ,no4 #c1 when the key is not on it4 ,the curved lever is double1 and the pinion segment turns loosely between the halves and on the shaft1 ,a2 it is held up in its place by a light spring1 ,f2 the weight1 ,e1 is also held between the two halves of the double lever4 ,illustration3 ,fig4 #hh4 ,maintaining ,power4 ,the action is as follows3 ,the end of the lever1 ,b1 covers the end of the winding shaft so that it is necessary to raise it before putting the key on the winding shaft2 it is raised till it strikes a stop1 and then pushed in till the pinion segment engages with the going wheel of the train1 when the weight1 ,e1 acting through the levers1 furnishes power to drive the clock train while the going weight is being wound up4 ,of course the weight on the maintaining power must be so proportioned to the leverage that it will be equal to the power of the going barrel and its weight1 a simple proposition in mechanics4 ,the number of teeth on the pinion segment1 ,c1 is sufficient to maintain power for fifteen minutes1 at the end of which time the lever1 ,b1 will come down and again cover the end of the winding shaft2 or1 it may be pumped out of gear and dropped down4 ,in case it is forgotten1 the spring1 ,f1 will allow the segment to pass out of gear of itself and will simply allow it to give a click as it slips over each tooth in the going wheel2 if this were not provided for1 it would stop the clock4 ,,chapter ,,xvi4 ,,motion ,,work ,,and ,,striking ,,trains4 ,motion work is the name given to the wheels and pinions used to make the hour hand go once around the dial while the minute hand goes twelve times4 ,here a few preliminary observations will do much toward clearing up the operations of the trains4 ,the reader will recollect that we started at a fixed point in the time train1 the center arbor which must revolve once per hour1 and increased this motion by making the larger wheels drive the smaller 7pinions7 until we reached sixty or more revolutions of the escape wheel to one of the center arbor4 ,this gearing to increase speed is called 8gearing up0 and in it the pinions are always driven by the wheels4 ,in the case of the hour hand we have to obtain a slowing effect and we do so by making the smaller wheels 7pinions7 drive the larger ones4 ,this is called 8gearing back0 and it is the only place in the clock where this method of gearing occurs4 ,we drew attention to a common usage in the gearing up of the time trains--that of making the relations of the wheels and pinions #h to one and #g4e to one2 #g4e #h #fj4 ,so we find a like usage in our motion work1 viz41 #c to one and #d to one2 #c #d #ab4 ,say the cannon pinion has twelve teeth2 then the minute wheel generally has #cf1 or three to one1 and if the minute wheel pinion has #aj1 the hour wheel will have #dj1 or four to one4 ,of course1 any numbers of wheels and pinions may be used to obtain the same result1 so long as the teeth of the wheels multiplied together give a product which is twelve times that of the pinions multiplied together2 but three and four to one have been settled upon1 just as the usage in the train became fixed1 and for the same reasons2 that is1 these proportions take up the least room and may be made with the least material4 ,also1 the pinion with the greatest number of teeth1 being the larger1 is usually selected as the cannon pinion1 as it gives more room to be bored out to receive the cannon1 or pipe4 ,if placed outside the clock plate1 the minute wheel and pinion revolve on a stud in the clock plate2 but if placed between the frames1 they are mounted on arbors like the other wheels4 ,the method of mounting is merely a matter of convenience in the arrangement of the train and is varied according to the amount of room in the movement1 or convenience in assembling the movement at the factory1 little attention being paid to other considerations4 ,illustration3 ,fig4 #hi4 ,fig4 #ij4 ,the cannon pinion is loose on the center arbor and behind it is a spring1 called the center spring1 or 8friction10 ,figs4 #hi and #ij1 which is a disc that is squared on the arbor at its center and presses at three points on its outer edge against the side of the cannon pinion2 or it may be two or three coils of brass wire4 ,this center spring thus produces friction enough on the cannon to drive it and the hour hand1 while permitting the hands to be turned backward or forward without interfering with the train4 ,in ,french mantel clocks the center spring is dispensed with and a portion of the pipe is thinned and pressed in so as to produce a friction between the pipe and the center arbor which is sufficient to drive the hands2 this is similar to the friction of the cannon pinion in a watch4 ,illustration3 ,fig4 #ia4 ,in some old ,english house clocks with snail strike1 the cannon pinion and minute wheel have the same number of teeth for convenience in letting off the striking work by means of the minute wheel1 which thus turns once in an hour4 ,where this is the case the hour wheel and its pinion bear a proportion to each other of twelve to one2 usually there is a pinion of six leaves engaging a wheel of #gb teeth1 or seven and eighty-four are sometimes found4 ,in tower clocks1 where the striking is not discharged by the motion work1 the cannon pinion is tight on its arbor and the motion work is similar to that of watches4 ,see ,fig4 #ia4 ,the cannon pinion drives the minute wheel1 which1 together with its pinion1 revolves loosely on a stud in the clock plate1 or on an arbor between the frames4 ,the meshing of the minute wheel and cannon pinion should be as deep as is consistent with perfect freedom1 as should also that of the hour wheel and minute pinion in order to prevent the hour hand from having too much shake1 as the minute wheel and pinion are loose on the stud and the hour wheel is loose on the cannon1 so that a shallow depthing here will give considerable back lash1 which is especially noticeable when winding4 ,the hour wheel has a short pipe and runs loosely on the cannon pinion in ordinary clocks4 ,in quarter-strike cuckoos a different train is employed and the wheels for the hands are both on a long stud in the plate and both have pipes2 the minute wheel has #cb teeth and carries four pins on its under side to let off the quarters4 ,the hour wheel has #fd teeth and works close to the minute wheel1 its pipe surrounding the minute wheel pipe1 and held in position by a screw and nut on the minute pipe4 ,a wheel of #dh and a pinion of #h teeth are mounted on the sprocket arbor with a center spring for a friction1 the wheel of #dh meshing with the minute wheel of #cb and the #h-leaf pinion with the hour wheel of #fd4 ,it will be recollected that the sprocket wheel takes the place of the barrel in this clock and there is no center arbor as it is commonly understood4 ,the sprocket arbor in this case turns once in an hour and a half1 hence it requires #dh teeth to drive the minute wheel of #cb once in an hour1 as it turns one-third of a revolution 7or #af teeth7 every half hour4 ,the sprocket arbor1 turning once in an hour and a half1 makes eight revolutions in twelve hours and its pinion of eight leaves working in the hour wheel of #fd teeth turns the hour hand once in twelve hours4 ,in ordinary rack and snail striking work the snail is generally mounted on the pipe of the hour wheel1 so that it will always agree with the position of the hour hand and the striking will thus be in harmony with the position of the hands4 ,,striking ,,trains4--,it is only natural1 after finding certain fixed relations in the calculations of time trains and motion work1 that we should look for a similar point in striking trains1 well assured that we shall find it here also4 ,it is evident that the clock must strike the sum of the numbers #a1 #b1 #c1 #d1 #e1 #f1 #g1 #h1 #i1 #aj1 #aa1 #ab1 or #gh blows of the hammer1 in striking from noon to midnight2 this will be repeated from midnight to noon1 making #aef blows in #bd hours1 and if it is a #cj-;hour clock1 six hours more must be added2 blows for these will be #ba more1 making a total of #agg blows of the hammer for a #cj-;hour strike train4 ,the hammer is raised by pins set in the edge of a wheel1 called the pin wheel1 and as one pin must pass the hammer tail for every blow1 it is evident that the number of pins in this wheel will govern the number of revolutions it must make for #agg blows1 so that here is the base or starting point in our striking train4 ,if there are #ac pins in the pin wheel1 it must revolve #ac4e times for #agg blows2 if there are #h pins1 then the wheel must revolve #bb4abe times in giving #agg blows2 consequently the pinions and wheels back to the spring or barrel must be arranged to give the proper number of revolutions of the pin wheel with a reasonable number of turns of the spring or weight cord1 and it is generally desirable to give the same1 or nearly the same1 number of turns to both time and striking barrels4 ,if it is an eight-day clock the calculation is a little different4 ,there are #aef blows every #bd hours2 then as the majority of 8eight-day0 clocks are really calculated to keep time for seven and a half days1 although they will run eight1 we have3 #aef #g4e #a1jgj blows in #g4e days4 ,with #ac pins we have #a1jgj #ac #hj and _/ths revolutions in the #g4e days4 ,if now we put an #h-leaf pinion on the pin wheel arbor and #hd teeth in the great wheel or barrel1 we will get #aj4e turns of the pin wheel for every turn of the spring or barrel2 consequently eight turns of the spring will be enough to run the clock for the required time1 as such clocks are wound every seventh day4 ,figuring forward from the pin wheel1 we find that we shall have to lock our striking train after a stated number of blows of the hammer each hour2 these periods increase by regular steps of one blow every hour1 so that we must have our locking mechanism in position to act after the passage of each pin1 whether it is then used or not2 so the pinion that meshes with the pin wheel1 and carries the locking plate or pin on its arbor must make one revolution every time it passes a pin4 ,if this is a #f-leaf pinion1 the pins on the pin wheel must therefore be #f teeth apart2 or an #h-leaf pinion must have the pins #h teeth apart2 and vice versa4 ,for greater convenience in registering1 the pins are set in a radial line with the spaces of the teeth in the pin wheel1 as this allows us to measure from the center of the pinion leaf4 ,it will thus be seen that the calculation of an hour striking train is a simple matter2 but if half hours are also to be struck from the train1 it will change these calculations4 ,for a #cj-;hour train #bd must be added to the #aef blows for #bd hours1 #ahj blows being required to strike hours and half hours for #bd hours4 ,these blows may be provided for by more turns of the spring1 or different numbers of the wheels and pinions1 which would then also vary the spacing of the pins4 ,half hours may also be struck directly from the center arbor1 by putting an extra hammer tail on the hammer arbor1 further back1 where it will not interfere with the hammer tail for the pin wheel1 and putting a cam on the center arbor to operate this second hammer tail4 ,this simplifies the train1 as it enables the use of a shorter spring or smaller wheels while providing a cheap and certain means of striking the half hours4 ,half-hour trains are frequently provided with a separate bell of different tone for the half hours1 as with only one bell the clock strikes one blow at #ab3cj1 #a and #a3cj1 making the time a matter of doubt to one who listens without looking1 as frequently happens in the night4 ,illustration3 ,fig4 #ib4 ,eight ,day ,hour and ,half ,hour ,strike4 ,fig4 #ib shows an eight-day1 ,seth ,thomas movement1 which strikes the hours on a count wheel train and the half hours from the center arbor4 ,all the wheels1 pinions1 arbors1 pins1 levers and hooks are correctly shown in proper position1 but the front plate has been left off for greater clearness4 ,the reader will therefore be required to remember that the escape wheel1 pallets1 crutch1 pendulum and the stud for the pendulum suspension are really fixed to the front plate1 while in the drawing they have no visible means of support1 because the plate is left off4 ,the time train occupies the right-hand side of the movement and the striking train the left hand4 ,running up the right-hand from the spring to the escape wheel1 we find an extra wheel and pinion which is provided to secure the eight days' run4 ,we also see that what would ordinarily be the center arbor is up in the right corner and does not carry the hands2 further1 the train is bent over at a right angle1 in order to save space and get the escape wheel in the center at the top of the movement4 ,the striking train is also crowded down out of a straight line1 the locking cam being to the right of the pin wheel and the warning wheel and fly as close to the center as possible4 ,this leaves some space between the pin wheel and the intermediate wheel of the time train and here we find our center arbor1 driven from the intermediate wheel by an extra pinion on the minute wheel arbor1 the minute wheel meshing with the cannon pinion on the center arbor4 ,this rearranging of trains to save space is frequently done and often shows considerable ingenuity and skill2 it also will many times serve to identify the maker of a movement when its origin is a matter of doubt and we need some material1 so that the planting of trains is not only a matter of interest1 but should be studied1 as familiarity with the methods of various factories is frequently of service to the watchmaker4 ,fig4 #ic is the upper portion of the same striking train1 drawn to a larger scale for the sake of clearness4 ,it also shows the center arbor1 both hammer tails and the stop on the hammer arbor1 which strikes against the bottom of the front plate to prevent the hammer-spring from throwing the hammer out of reach of the pins4 ,the pin wheel1 ,r1 and count wheel1 ,e1 are mounted close together and are about the same size1 so that they are shown broken away for a part of their circumferences for greater clearness in explaining the action of the locking hook1 ,c1 and the locking cam1 ,d4 ,fig4 #id shows the same parts in the striking position1 being shown as just about to strike the last blow of #ab4 ,similar parts have similar letters in both figures4 ,the count wheel1 ,e1 is loose on a stud in the plate1 concentric with the arbor of the pin wheel1 ,r4 ,the pivot of ,r runs through this stud4 ,the sole office of the count wheel is to regulate the distance to which the locking hook ,c1 is allowed to fall4 ,the count hook1 ,a1 and the locking hook1 ,c1 are mounted on the same arbor1 ,b1 so that they move in unison4 ,if ,a is allowed to fall into a deep slot of the count wheel1 ,c will fall far enough to engage the locking face of the cam ,d and stop the train1 as in ,fig4 #ic4 ,if1 on the contrary1 ,a drops on the rim of the wheel1 ,c will be held out of the locking position as ,d comes around 7see ,fig4 #id71 and the train will keep on running4 ,it will be seen that after passing the locking notch1 ,d1 ,fig4 #id1 will in its turn raise the hook ,c1 which will ride on the edge of ,d1 and hold ,a clear of the count wheel until the locking notch of ,d is again reached1 when a deep notch in the wheel will allow ,c to catch1 as in ,fig4 #ic1 unless ,c is stopped by ,a falling on the rim of the wheel1 as in ,fig4 #id4 ,illustration3 ,fig4 #ic4 ,upper ,portion of ,striking ,train ,locked4 ,illustration3 ,fig4 #id4 ,striking ,train ,unlocked and ,running4 ,one leaf1 ,f1 of the pinion of the locking arbor sticks out far enough to engage with the count wheel teeth and rotate the wheel one tooth for each revolution of ,d1 so that ,f forms a one-leaf pinion similar to that of a rack striking train4 ,here we have our counting mechanism2 ,f and ,d go around together2 ,f moves ,e one tooth every revolution4 ,a holds ,c out of action 7,fig4 #id7 until ,a reaches a deep slot1 when ,c stops the train by engaging ,d 7,fig4 #ic74 ,the count wheel1 ,e1 must have friction enough on its stud so that it will stay where the pin ,f leaves it1 when ,f goes out of action and thus it will be in the right position to suitably engage ,f on the next revolution4 ,too much friction of the count wheel on its stud will use too much power for ,f to move it and thus slow the train2 if there is too little friction here the count wheel may get in such a position that ,f will get stalled on the top of a tooth and stop the train4 ,the count hook1 ,a1 must strike exactly in the middle of the deep slots1 without touching the sides of the slots in entering or leaving1 as to do this would shift the position of the count wheel if the rubbing were sufficient1 or it might prevent ,a from falling 7as ,a and ,c are both very light7 and the clock would go on striking4 ,if the hook ,a does not strike the middle of the spaces between the teeth of the count wheel1 it will gradually encroach on a tooth and push the wheel forward or back1 thus disarranging the count4 ,many a clock has struck #ac for #ab in this way because the hook was a little out4 ,this did not occur in the smaller numbers because the action was not continued long enough to allow the hook to reach a tooth4 ,the pin1 ,f1 should also mesh fairly and freely in the teeth of the count wheel1 or a similar defect is likely to occur4 ,when repairing or making new count hooks1 ,a1 ,figs4 #ic and #id1 they must be of such a length that they will enter the slots on a line radial with the center of the wheel4 ,the proper length and direction are shown at ,a1 ,fig4 #ie1 while ,b and ,c are wrong4 ,with hooks like either ,b or ,c you can set or bend the hook to strike right at one and as you turn the clock ahead the hook does not fall in far enough and at twelve it only strikes eleven4 ,then if you bend the same hook to strike right at twelve it will strike two at one and as you turn the clock ahead it will strike right at about five or seven4 ,a1 ,fig4 #ie1 being of the proper length and shape will give no trouble4 ,many of the count wheels of the older clocks were divided by hand and are not as accurate as they should be2 when a wheel of this kind is found and a new wheel cannot be substituted 7because the clock is an antique and must have the original parts preserved7 it will sometimes require nice management of the hook ,a to obtain correct striking4 ,a little manipulation of the pinion1 ,f1 ,fig4 #ic is sometimes desirable also1 if the count wheel is very bad4 ,illustration3 ,fig4 #ie4 ,the proper length of the count hook4 ,the locking face of the cam1 ,d1 must also be on a line radial to its center1 or it will either unlock too easily and go off on the slightest jar or movement of the clock1 or the face will have too much draw and the hook ,c will not be unlocked when the clock is fully wound1 and the spring pressure is greatest4 ,in this case the clock will not strike when fully wound1 but will do so when partly run down1 and as the count wheel train strikes in rotation1 without regard to the position of the hands1 you will have irregular striking of a most puzzling sort4 ,repairs to this notch are sometimes required1 when the corner has become rounded1 and the best way to make them is to cut a new face on the cam with a sharp graver1 being careful to keep the face radial with its center4 ,because the count wheel strikes the hours in rotation1 regardless of the position of the hands1 if the hands are turned backwards past the figure #ab on the dial the striking will be thrown out of harmony with the hands4 ,to remedy this the count hook1 ,a1 has an eye on its rear end and a wire1 shown in ,fig4 #ib1 hangs down to where it can be reached with the hand when the dial is on4 ,pulling this wire will lift ,a and ,c and cause the clock to strike2 by this means the clock may be struck around until the position of the striking train agrees with that of the hands4 ,where this wire is not present the striking is corrected by turning the hands back and forth between ,,ix and ,,xii until the proper hour is struck4 ,now we come to the releasing mechanism1 which causes the clock to strike at stated times4 ,i1 ,figs4 #ic and #id1 is an arbor pivoted between the plates and carrying three levers1 ,h1 ,k and ,j1 in different positions on the arbor4 ,h is directly under the count hook1 ,a1 and lifts ,a and ,c whenever ,j is pushed far enough to one side by ,l on the center arbor1 which revolves once an hour4 ,thus ,l1 through ,j1 ,h and ,a1 ,c1 unlocks the train once every hour4 ,when ,c is thus lifted the train runs until the warning pin1 ,o1 ,figs4 #ic and #id1 strikes against the lever ,k1 which is on the same arbor with ,h and ,j4 ,this preliminary run of the train makes a little noise and is called 8warning10 as the noise notifies us that the train is in position to commence striking4 ,the lever ,k and the warning pin1 ,o1 then hold the train until ,l has been carried out of action with ,j and released it1 when ,o will push ,k out of its path at every revolution and the clock will strike4 ,the half hours are struck by ,l pressing the short hammer tail1 ,g1 and thus raising and releasing the hammer once an hour4 ,in setting up the striking train after cleaning1 place the pin wheel so that the hammer tail1 ,g1 may be about one-fourth of the distance from the next pin1 as shown in ,fig4 #ic2 this allows the train to get well under way before meeting with any resistance and will insure its striking when nearly run down4 ,if the hammer tail is too close to the pin1 it might stop the train when there is but little power on4 ,then place ,d in the locked position1 with ,a in a deep slot of the count wheel and ,c in the notch of ,d4 ,next place the warning wheel with its pin1 ,o1 on the opposite side of its arbor from the lever ,k1 see ,fig4 #ic4 ,this is done to make sure that when it is unlocked for 8warning0 the train will run far enough to get the corner of the lock1 ,d1 safely1 past ,c1 so that it will not allow ,c to fall into the notch again and lock the train when ,j1 ,k and ,h are released by ,l4 ,this is the rule followed in assembling these clocks at the factories and is simple1 correct and easily understood4 ,a study of these points in ,fig4 #ic will enable any one to set up a train correctly before putting the front plate on4 ,if the workman gets a clock that has been butchered by some one who did not understand it 7and there are many such71 he may find that when correctly set up the clock does not strike on the #fjth minute of the hour2 in such a case a little bending of ,j1 in or out as the case may be1 will usually remedy the trouble4 ,the same thing may have to be done to the hammer tails1 ,g and ,g1 or the stop on the hammer arbor4 ,if both hammer tails are out of position1 bend the stop2 if one is right1 let the stop alone and bend the other tail4 ,a rough1 set or gummy spring will cause irregular striking4 ,in such a case the clock will strike part of the blows and then stop and finally go on again and complete the number4 ,much time has been lost in examining the teeth of wheels and pinions in such cases when the trouble lay in the spring4 ,too strong a spring will make the movement strike too fast2 too weak a spring will make it strike slow1 especially in the latter part of the day or week1 when it has nearly run down4 ,too small a fan1 or a fan that is loose on its arbor1 will allow the clock to strike too fast4 ,if this fan is badly out of balance it will prevent the train from starting when there is but little power on4 ,there is a class of clocks which have the count wheel tight on the arbor1 outside the clock plate4 ,many of them are on much tighter than they should be4 ,in such a case take an alcohol lamp and heat the wheel evenly1 especially around the hub2 the brass will expand twice as much as the steel and the wheel may then be driven off without injury4 ,fig4 #if shows another typical ,american eight-day train1 made by the ,gilbert ,clock ,company1 and striking the half hours from the train4 ,here we notice1 on comparing with ,fig4 #ib1 that there are many points of difference4 ,first the notches on the count wheel are twice as wide as they are in ,fig4 #ib4 ,this means that half hours are struck on the train2 this will be explained later4 ,next there are two complete sets of notches on the wheel1 which shows that the wheel turns only once in twenty-four hours1 whereas the other makes two revolutions in that time4 ,there are no teeth on the count wheel1 so that it must be fast to its arbor1 which is that of the great wheel and spring1 while ,fig4 #ib has a separate stud and it is loose4 ,the wheel being on the spring arbor and going once in #bd hours1 there must be one turn of spring for each #bd hours which the train runs4 ,there is no pin wheel in ,fig4 #if1 but instead of this two pins are cut out of the locking cam to raise the hammer tail as they pass4 ,there are also two locking notches in the locking cam4 ,the cams on the center arbor are stamped out of brass sheet1 while those of ,fig4 #ib were of wire4 ,illustration3 ,fig4 #if4 ,half hours struck on the train4 ,turning to the enlarged view in ,fig4 #ig and comparing it with ,fig4 #ic1 we find further differences4 ,the levers ,k and ,j are here made of one piece of brass1 while the others were separate and of wire4 ,the lifting lever1 ,h1 is flattened at its outer end in ,fig4 #ic1 while in ,fig4 #ig it is bent at right angles and passed under the count hook1 ,a4 ,the hook1 ,c1 ,fig4 #ig1 is added to the arbor1 ,b1 as a safety device1 in case the locking hook should fail to enter its slot in the cam1 ,d4 ,it is shown as having just stopped the warning pin in ,fig4 #if4 ,there is but one hammer tail1 ,g1 and the hammer stop acts against the stud for the hammer-spring1 instead of against the bottom of the front plate1 as in ,fig4 #ib4 ,the first important difference here is in the position of the count hook1 ,a4 ,in ,figs4 #ib and #ic the hook must be exactly in the middle of the slot1 or there will be trouble4 ,in trains striking half hours from the train1 we must never allow the hook to occupy the middle of the slot1 or we will have more trouble than we ever dreamed of4 ,in this instance the count hook must enter the slot close to 7but not touching7 the side of the slot when the clock stops striking2 then when the half hour is struck the count wheel will move a little and the hook must drop back into the same slot without touching2 this brings it close to the opposite side of the same slot and the next movement will land the hook safely on top of the wheel for the strokes of the hour4 ,fig4 #if shows its position after striking the half hour and ready to strike the hour of two4 ,fig4 #ig shows it dropping back after striking two4 ,illustration3 ,fig4 #ig4 ,half hour strike on the count wheel4 ,in setting up this train1 see that the count hook4 ,a1 goes into the slot of the count wheel close to1 but not touching1 one side of the slot in the count wheel1 and1 after placing the intermediate1 insert the locking cam1 ,d1 so that it engages the locking hook2 then put in the warning wheel with the warning pin1 ,o1 safely to the left of the hook ,c1 ,fig4 #ig1 so that it cannot get past that hook after striking4 ,placing the wheel with its warning pin six or eight teeth to the left of the edge of the bottom plate is generally about right4 ,the action of the levers1 ,h1 ,j1 ,k1 the hammer tail1 ,g1 and the cam1 ,l1 in striking the hours is the same as that already described in detail for ,figs4 #ic and #id1 hence need not be repeated here4 ,l strikes the half hours by being enough shorter than ,l to raise the hooks for one revolution1 but not quite so high as for the hours4 ,the cams ,l1 ,l are friction-tight on the center arbor and may be shifted on the arbor to register the striking on the #fjth minute1 if desired4 ,when the hands and strike do not agree1 turn the minute hand back and forward between ,,ix and ,,xii1 thus striking the clock around until it agrees with the hands4 ,sometimes1 if the warning pin is not far enough away1 an eight-day clock will strike all right for a number of days and then commence to gain or lose on the striking side4 ,it either does not strike at some hours1 or half hours1 or it may strike sometimes both hour and half hour before stopping4 ,take the movement out of the case and put the hands on2 then move the minute hand around slowly until the clock warns4 ,look carefully and be sure there is no danger of the clock striking when it warns4 ,if this looks secure1 then move the hand to the hour1 making it strike2 say it is going to strike #i o'clock2 when it has struck eight times1 stop the train with your finger and let the wheels run very slow while striking the last one1 and when the rod drops into the last notch stop the train again and hold it there4 ,for the striking part to be correct1 the warning pin on the wheel wants to be about one-fourth of a revolution away from the rod when the clock has struck the last time1 or as soon as this rod falls down far enough to catch the pin4 ,the object of this is so there is no chance of the warning pin getting past the rod at the last stroke2 this it is liable to do if the pin is too close to the rod when the rod drops4 ,if you will examine the clock as above1 not only when it strikes ,,ix1 but all the hours from ,i to ,,xii1 you will generally find the fault4 ,of course1 if the pin is too close to the rod when the rod drops1 you must lift the plates apart and change the wheel so that the warning pin and the rod will be as explained4 ,,ship',s ,,bell ,,striking ,,work4--,of all the count wheel striking work which comes to the watchmaker1 the ship's bell is most apt to give him trouble4 ,this generally arises from ignorance as to what the system of bells on shipboard consists of and how they should be struck4 ,if he goes to some nautical friend1 he hears of long and short 8watches0 or 8full watches0 and 8dog watches40 ,if he insists on details1 he gets the information that a 8watch0 is not a horological mechanism1 but a period of duty for a part of the crew4 ,then he is told of the 8morning watch10 8first dog watch10 8afternoon watch10 8second dog watch10 8off watch10 8on watch10 etc4 ,now the ship's bell clock does not agree with these 8watches0 and was never intended to do so4 ,as a matter of fact1 it is simply a clock striking half hours from one to eight and then repeating through the twenty-four hours4 ,the striking is peculiarly timed and is an imitation of the method in which the hours are struck on the bell of the ship4 ,as this bell is also used for other purposes1 such as tolling in fogs1 fire alarms1 church services1 etc41 it will readily be seen that a different method of striking for each purpose is desirable to avoid misunderstanding of signals4 ,illustration3 ,fig4 #ih4 ,ships bell clock4 ,the method of striking for time is to give the blows in couples1 with a short interval between the strokes of the couples and three times that interval between the couples4 ,odd strokes are treated as a portion of the next couple and separated accordingly1 thus3 #ab3cj p4 m4 ,one ,bell1 ,o #a3jj p4 m4 ,two ,bells1 ,o ,o #a3cj p4 m4 ,three ,bells1 ,o ,o ,o #b3jj p4 m4 ,four ,bells1 ,o ,o ,o ,o #b3cj p4 m4 ,five ,bells1 ,o ,o ,o ,o ,o #c3jj p4 m4 ,six ,bells1 ,o ,o ,o ,o ,o ,o #c3cj p4 m4 ,seven ,bells1 ,o ,o ,o ,o ,o ,o ,o #d3jj p4 m4 ,eight ,bells1 ,o ,o ,o ,o ,o ,o ,o ,o ,after striking eight bells the clock repeats1 although the ship's bell is generally struck in accordance with the two dog watches 7which are of two hours' duration each7 before commencing the evening watch 7#h to #ab p4 m474 ,it will thus be seen that the clock should strike eight at #ab m41 #d p4 m41 #h p4 m41 #ab p4 m41 #d a4 m41 and #h a4 m4 ,illustration3 ,fig4 #ajj4 ,the pins on the count wheel of the ships bell clock4 ,in order to strike the blows in pairs two hammers are necessary1 see ,fig4 #ih2 these hammers are placed close together1 but not in the same plane4 ,the pin wheel has twenty pins1 see ,figs4 #ih1 #ii1 #ajj2 some of these pins are shorter than the others1 so that they do not operate one of the hammer tails4 ,these are shown graphically in ,fig4 #ajj2 where the two oblong marks at figure #a represent the tops of the hammer tails shown in ,fig4 #ii4 ,it will be seen by studying ,fig4 #ajj that with the wheel moving from left to right1 the inside hammer tail will be operated for one blow1 while the outer hammer tail will not be operated at all1 thus giving but one blow1 or 8bell40 ,at the next movement of the pin wheel1 the outside hammer will be operated by the long pin and the inside hammer by the short pin1 thus giving one blow of each hammer1 or 8two bells40 ,illustration3 ,fig4 #ii4 ,enlarged view of striking work1 ships bell clock4 ,we now have these hammer tails advanced along the wheel so that the outside one is opposite the figure #c in the drawing1 while the other is opposite the figure #b1 with one pin between them4 ,the next movement of the pin wheel advances them so that the outside hammer will pass the next short pin and consequently that hammer will miss one blow and the pair will therefore strike three--one by the outside hammer and two by the inside4 ,it thus goes on until the cycle is completed1 eight blows being struck with the last four pins4 ,the striking in pairs is effected by having the two hammer tails close together1 so that the pins will operate both hammer tails quickly and there will then be an interval of time while the wheel brings forward the next pins4 ,this is so spaced that the interval between pairs is three times that between the blows of a pair and the hammer tails should not be bent out of this position1 or if found so they should immediately be restored to it4 ,tolling the bells1 instead of striking them properly1 is very bad form at sea and generally leads to punishment if persisted in1 so that the jeweler will readily perceive that his marine customers are very particular on this point1 and he should go any length to obtain the proper intervals in striking4 ,the pin wheel moves forward one pin for each couple of blows or parts of a couple1 the odd blows being secured by the failure of the blow when the hammer tail passes the short pin4 ,thus it moves as far for one bell as for two bells2 as far for three bells as for four1 etc4 ,the result is that the count wheel has no odd numbers on it1 but instead two #b's1 two #d's1 two #f's and two #h's2 the first two are counted on the count wheel1 but only one is struck on the pin wheel1 owing to the short pin2 this is repeated at three1 five and seven1 when four1 six and eight are counted on the wheel1 but the last blow fails of delivery1 owing to the short pin in the pin wheel at these positions4 ,the center arbor carries two pins1 ,l and ,l1 to unlock the train through the lever ,j1 as it is really a half hour striking clock4 ,the count hook1 ,a2 locking hook1 ,c2 count wheel1 ,e2 pins1 ,p1 and other parts have similar letters for similar parts as in the preceding figures and need not be further explained1 as the mechanism is otherwise similar to the ,seth ,thomas movement shown in ,fig4 #ib4 ,,chapter ,,xvii4 ,,cleaning ,,and ,,repairing ,,cuckoo ,,clocks4 ,the cuckoos are in a class by themselves for several reasons1 all of which have to do with their construction and should therefore be understood by the watchmaker4 ,they are bought as timepieces by but two classes of people3 those who were used to them in their former homes in ,europe and buy them for sentimental reasons2 and those who admire fine wood carvings as works of art and desire to possess a finely carved cuckoo clock for the reasons which govern in the purchase of paintings and statuary1 bronzes1 and other art objects4 ,for this reason cuckoos have never been a success when attempts have been made to cheapen their production by the use of imitations of wood carving in composition or metal4 ,the use of cuckoos in plain cases1 with springs instead of weights1 has also been attempted with the idea of thereby securing an inclosed movement1 as in ordinary clocks2 but while it offers advantages in cleanliness and protection of the movement1 such clocks have never become popular1 as they have lost their character as works of art by being enclosed in plain cases1 or have become rather erratic in rate by the substitution of springs for weights4 ,the use of exposed weights and pendulum necessitates openings in the bottom of the case through which the dust enters freely and this makes necessary unusual side shake1 end shake and freedom of depthing of the wheels and pinions and also the use of lantern pinions and an amount of driving weight in excess of that necessary for protected movements1 as there must be enough weight to pull the cuckoo movement through obstructions which would stop the ordinary movement4 ,repairers therefore should not attempt to close worn holes as snugly as in the ordinary movements1 as when this is done the clock generally stops about three weeks after it has left the shop and a 8comeback0 is the result4 ,lightening the driving weights will have the same result1 as the movement must have sufficient power to pull it through when dirty4 ,as the plates and wheels are generally of cast metal1 cutting of pivots from running dry is frequent in old clocks1 and where it is necessary to close the holes care must be taken not to overdo it4 ,another point where repairers fail is in not polishing the pivots4 ,many watchmakers seem to think that any kind of a pivot will do for a clock1 although they take great care of them in their watchwork4 ,rough and dry pivots will cut the holes in a clock plate deep enough to wedge the pivots in the holes like a stuck reamer and stop a clock just after it has been repaired1 when if they had been properly polished the job would not have come back4 ,the high prices of wood carving in ,america and the necessity for its genuineness1 as explained above1 has resulted in making it necessary to spend as little as possible for the movements2 hence we ordinarily find a total lack of finish on the movements1 and this1 with the great freedom everywhere evident in its construction and the apparent excess of angular motion of the levers1 combine to give it an appearance of roughness which surprises those who see them but rarely4 ,it has been frequently suggested by watchmakers that if the cases only were imported and the movements were made by the ,american factories better results should be obtained1 in appearance at least4 ,they forget that the bellows1 pipes and birds1 with their wires1 are parts of the movements and the cost of having these portions made in this country is prohibitive1 so that the whole movement is imported4 ,arrangements are now being made by at least one firm to have the frames and wheels made of sheet metal by automatic machinery1 instead of being cast and finished in the usual way1 and when this is done the appearance of the movements will be greatly improved1 so that ,american watchmakers will regard them with a more kindly eye4 ,so far as is known to the writer all cuckoo movements are imported1 although one firm is doing a large and constantly growing trade in such clocks with cases made in ,america4 ,there are a number of importing firms who sell to jobbers1 large retailers and clock companies only1 and as the large ,american clock manufacturers all list and carry cuckoos the clocks find their way to the consumer through many and devious channels4 ,probably more are sold in other ways than through the retailers for the reason that the average retailer does not understand the cuckoos and is reluctant to stock them1 thereby deliberately avoiding a large amount of business from which he might make a handsome profit4 ,under the general term ,cuckoos are listed several kinds of movements1 all having bellows1 pipes and moving figures1 such as the cuckoo1 cuckoo and quail1 trumpeter1 etc41 with or without the regular hammers and gongs of the ordinary movements4 ,figs4 #aja and #ajb show front and back views of a time train in the center with quail strike train on the left and cuckoo strike train at the right4 ,the positions of arbors1 levers1 depthings of trains1 etc41 are exact1 but the movement plates have been left off for greater clearness1 so that the arbors appear to be without support4 ,the positions of the pillars are shown by the shaded circles above and below the trains in ,fig4 #aja4 ,the parts have the same letters in both ,figs4 #aja and #ajb1 although as the movement is turned around to show the rear in #ajb1 the quail train appears on the right side4 ,illustration3 ,fig4 #aja4 ,front ,view of ,quail and ,cuckoo ,strike ,movement4 ,,names ,,of ,,parts4 ,a--,quail count wheel4 ,b--,quail striking cam4 ,c--,minute wheel4 ,d--,quail lifting lever4 ,e--,quail count hook4 ,f--,quail locking arm4 ,g--,quail bird stick2 also called bird holder4 ,h--,quail bellows arm4 ,i--,quail bellows lifting lever4 ,j--,quail gong hammer4 ,k--,quail warning lever4 ,l--,quail lifting pin4 ,m--,quail bird stick lever4 ,n--,quail hammer lever4 ,o--,quail ,lifting pin wheel4 ,p--,cuckoo lifting lever4 ,q--,cuckoo warning lever4 ,r--,cuckoo lifting pin4 ,s--,cuckoo locking arm4 ,t--,cuckoo count hook4 ,u--,cuckoo striking cam4 ,v--,cuckoo lifting pin wheel4 ,w--,cuckoo count wheel4 ,x--,cuckoo bellows lifting lever4 ,y--,cuckoo hammer4 ,z--,cuckoo bird stick2 also called bird holder4 ,s--,cuckoo bird stick lever4 ,in examining a movement the student discovers a peculiarity of cuckoo frames1 which is that the pivot holes for several of the arbors of the striking levers have slots filed into them1 reaching to the edges of the frames and narrower than the full diameter of the pivot holes4 ,this is because such arbors have levers riveted into them which must function in front1 between and at the rear of the plates and in setting up the movement the slots are necessary to allow the end levers to pass through the holes4 ,such arbors as have slots on the front plates are inserted and placed in their proper positions before setting the train wheels with which they function4 ,the others are first inserted in the back plate and turned to position while putting on that plate4 ,both quail and cuckoo trains are set up very simply and surely by observing the following points3 ,in the quail train1 when the quail bellows lever1 ,h1 is just released from a pin in the pin wheel1 ,o1 the locking lever1 ,f1 must just fall into the slot of the locking cam1 ,b2 the warning pin should then be near the fly pinion and the count hook1 ,k1 drop freely into the count wheel1 ,a4 ,illustration3 ,fig4 #ajb4 ,rear ,view of ,quail and ,cuckoo ,movement4 ,on the cuckoo side we find two levers1 ,x2 the upper one of these operates the low note of the cuckoo call and the lower one the high note4 ,when this upper lever is released from a pin in the pin wheel1 the cuckoo locking lever1 ,s1 must drop into its locking cam1 ,u1 and the count hook1 ,t1 drop into its count wheel1 while the warning pin must be near the fly pinion4 ,after the run has stopped and the trains are fully locked the warning pins will be as shown in ,fig4 #ajb2 but at the moment of locking they should be as described above4 ,the operation is as follows3 ,turning to ,fig4 #aja1 we find the minute wheel1 ,c1 has four pins projecting from its rear surface4 ,this revolves once per hour and consequently the pins raise the lifting lever1 ,d1 every fifteen minutes4 ,here is a point that frequently is productive of trouble4 ,the reader will readily see that if the hands of a cuckoo are turned backward the pins in the minute wheel will bend this wire1 ,d1 and derange the striking1 as the warning lever is also attached to the same arbor4 ,never push the hands backward on a cuckoo clock2 always push them forward4 ,if the striking and hands do not register the same time1 take off the weights of the striking trains2 then push the hands forward until they register the hour which the trains struck last4 ,as there is no power on the trains they will not be operated1 the only action being the rising and falling of the lever1 ,d1 as the pins pass4 ,when the hands point to the hour last struck by the trains1 put on the striking weights again and push the hands forward1 allowing time for each striking1 until the clock has been set to the correct time4 ,upon the lifting lever1 ,d1 being raised sufficiently the warning lever1 ,e1 on the same arbor is lifted into the path of the warning pin and at the same time unlocks the train by pressing against the lifting pin1 ,l1 in the locking lever1 ,f4 ,the locking lever1 ,f1 count hook1 ,k1 and the bird holder lever1 ,m1 are all on the same arbor and therefore work in unison4 ,when ,d drops1 ,e releases the warning pin and the train starts4 ,the pin wheel has pins on both sides1 the rear pins operate the gong hammer1 ,n1 ,j2 the front pins operate the quail bellows1 ,i1 ,h4 ,the rising1 and falling of the unlocking lever1 ,f1 operates the bird holder1 ,g1 through ,m and the wire in the bellows top tilts the tail of the bird and flutters the wings4 ,when the fourth quarter has been struck1 the pins shown in the quail count wheel1 ,a1 operate the hour lifting lever1 ,p1 and the action of that train becomes similar to that of the quarter train just described1 with the difference that there are two bellows levers1 ,x1 for the high and low notes of the cuckoo1 whereas there is but one for the quail4 ,there are several adjustments necessary to watch on these clocks4 ,the wires to operate the bellows from the levers ,x and ,h may be so long that the bellows when stretched to its full capacity may not allow the tails of ,x and ,h to clear the pins of the pin wheels and thus stop the trains4 ,the pins should clear safely with the bellows fully opened4 ,the levers ,m and ,s1 which operate the bird holders1 ,g and ,z1 may be turned in their arbors so as to be farther from or closer to the bird holder2 this regulates the opening and closing of the doors and the appearance of the birds2 if there is too much movement the birds may be sent so far out that they will not return1 but will stay out and stop the trains4 ,moving ,s and ,m towards the bird holders1 ,z and ,g1 will lessen the amount of this motion and the contrary movement will increase it4 ,another important source of trouble--because generally unsuspected--is the fly4 ,the fly on a cuckoo train must be tight2 a loose fly will cause too rapid striking and allow the train to overrun1 making wrong striking1 or in a very bad case it will not stop until run down4 ,when this happens turn your attention to the fly and make sure that it is tight before doing any bending of the levers1 and also see to the position of the warning pin4 ,sometimes the front of the case 7which is also the dial7 will warp and cause pressure on the ends of the lever arbors and thus interfere with their proper working4 ,be sure that the arbors are free at both ends4 ,when replacing worn pins in the striking trains1 care should be taken to get them the right length1 as on account of the large amount of end shake in these movements they may slip past the levers without operation1 if too short1 or foul the other parts of the train if too long4 ,for the same reasons bending the levers should only be done after exhausting the other sources of error and then be undertaken very slowly and cautiously4 ,the notes of a cuckoo are ,a and ,f1 just below middle ,c2 these should be sounded clearly and with considerable volume4 ,if they are short and husky in tone it may be due to holes in the bellows1 too short stroke of bellows1 removal of the bellows weights1 ,e1 ,fig4 #ajc1 dirt in the orifices of the pipes1 or cracks in the pipes4 ,holes in the bellows1 if small and not in the folds of the kid1 may be mended by being glued up with paper or kid1 or a piece of court plaster which is thin enough to not interfere with the operation of the bellows4 ,if much worn a new bellows should be substituted4 ,cracks in the pipes may be mended with paper4 ,the orifice of the pipe1 if dirty1 may be cleaned with a piece of mainspring filed very thin and smooth and carefully inserted1 as any widening or roughening of this slit will interfere with the tone4 ,sometimes a clock comes in which has been spoiled in this regard1 then it becomes necessary to remove the outer portion or lip1 ,a1 ,fig4 #ajc1 of the slot 7which is glued in position7 and make a new inner lip1 ,b1 or file the old one smooth again4 ,the proper shape is shown in ,b1 ,fig4 #ajc1 while ,c and ,d show improper shapes which interfere with the tone4 ,illustration3 ,fig4 #ajc4 ,cuckoo bellows and pipe4 ,a1 outer lip2 ,b1 inner lip2 ,c1 ,d1 incorrect forms of lip4 ,much time and money has been spent in trying to avoid the inherent defects of this portion of the clock2 sometimes the lips will swell or warp and close the orifice2 sometimes they will shrink and make it too wide2 in either case a loss of purity of tone is the result4 ,brass tubes1 if thin enough to be cheap1 give a brassy tone to the notes2 compositions of lead1 tin and antimony 7organ pipe metal7 are readily cast1 but give a softer1 duller tone of less volume than the wood4 ,celluloid lips to a wooden tube were at first thought to be a great success1 but were found to warp as they got older4 ,bone lips are costly2 so there is nothing at present that seems likely to displace well seasoned wood1 where discriminating lovers of music and art demand purity and correctness of tone1 reasonably accurate time1 artistic sculptural effects and durability1 all in one article--a high class cuckoo clock4 ,when sending a clock home after repairing1 each of the chains should be tied together with strings just outside the bottom of the case so that they will not slip off the sprockets and the customer should be instructed to hang the clock in its accustomed position before cutting the strings and attaching the weights4 ,,chapter ,,xviii4 ,,snail ,,striking ,,work1 ,,english1 ,,french ,,and ,,american4 ,while the majority of snail striking movements made in ,america are on the ,french system1 because they are cheaper when made in that way1 still this system is so condensed and so difficult to illustrate1 with all its mechanism packed in a small space between the plates1 that the student will gain a much better idea of the rack and snail and its principles by first making a study of an ,english snail striking clock1 which has the whole of the counting and releasing levers placed outside the front plate1 where they can occupy all the room that may be necessary4 ,the calculation and planting of the striking train do not differ from those using the count wheel1 up to and including the single toothed pinion or gathering pallet4 ,the stopping of the train after striking is different and the counting is divided1 being dependent upon four pieces acting in conjunction in an hour strike of the simplest order1 which number may run to a dozen in a repeating clock4 ,as the count wheel system had the defect of getting out of harmony with the hands when the latter are turned backward1 so the snail system has its defects1 which are the displacement of the rack and failure to stop the striking in some clocks if the striking train runs down before the time side and is then rewound1 and a most puzzling inaccuracy of counting1 resulting from slight wear and inaccuracy of adjustment4 ,we mention these things here because they have an influence on the construction of the clock and an advance knowledge of them will serve to make clearer some of the statements which follow4 ,,hour ,,and ,,half-,,hour ,,snail ,,striking ,,work4--,fig4 #ajd is a view of the front plate of an ,english fusee striking clock1 on the rack principle4 ,the going train occupies the right and center and the striking train the left hand4 ,the position of the trains is indicated in dotted lines1 the trains having barrels and fusees as shown by the squared arbors1 all the dotted work being between the clock plates1 and that in full lines being placed on the outside of the front plate1 under the dial4 ,the connection between the going train and the striking work is by means of the motion wheel on the center arbor1 and connection is made between the striking train and the counting work by the gathering pallet1 ,f1 which is fixed to the arbor of the last wheel but one of the striking train1 and also by the warning piece1 which is shown in black on the boss of the lifting piece1 ,a4 ,this warning piece goes through a slotted hole in the plate1 and during the interval between warning and striking stands in the path of a warning pin in the last wheel of the striking train4 ,the motion wheel on the center arbor1 turning once in an hour1 gears with the minute wheel1 ,e1 which has an equal number of teeth4 ,there are two pins opposite each other and equidistant from the center of the minute wheel1 which in passing raise the lifting piece1 ,a1 every half hour4 ,except for a few minutes before the clock strikes1 the striking train is kept from running by the tail of the gathering pallet2 ,f1 resting on a pin in the rack1 ,c4 ,just before the hour1 as the boss of the lifting piece1 ,a1 lifts the rack hook ,b1 the rack ,c1 impelled by a spring in its tail1 falls back until the pin in the lower arm of the rack is stopped by the snail1 ,d4 ,this occurs before the lifting piece1 ,a1 is released by the pin in the minute wheel1 ,e1 and in this position the warning piece stops the train4 ,exactly at the hour the pin in the minute wheel1 ,e1 gets past the lifting piece1 ,a1 which then falls1 and the train is free4 ,for every blow struck by the hammer the gathering pallet1 ,f1 which is really a one-toothed pinion1 gathers up one tooth of the rack1 ,c1 which is then held1 tooth by tooth1 by the point of the hook1 ,b4 ,after the pinion1 ,f1 has gathered up the last tooth1 its tail is caught by the pin in the rack1 which stops and locks the train1 and the striking ceases4 ,the snail1 ,o1 is mounted on a twelve-toothed star wheel1 placed on a stud in the plate1 so that a pin in the motion wheel on the center arbor moves it one tooth for each revolution of the motion wheel1 and it is then held in position by the click and spring as shown4 ,the pin1 in moving the star wheel1 presses back the click1 which not only keeps the star wheel steady1 but also completes its forward motion after the pin has pushed the tooth past the projecting center of the click4 ,the steps of the snail are arranged so that at one o'clock it permits only sufficient fall of the rack for one tooth to be gathered up1 and at every succeeding hour gives the rack an additional motion equal to one extra tooth4 ,it will be seen that where a star wheel is used a cord or wire attached to ,a and run outside the case1 so that ,a may be lifted1 will cause the clock to repeat the hour whenever desired4 ,the lower arm of the rack1 ,c1 and the lower arm of the lifting piece1 ,a1 are made of brass1 and thin1 so as to yield when the hands of the clock are turned back2 the lower extremity of the lifting piece1 ,a1 is a little wider1 and bent to a slight angle with the plane of the arm1 so as not to butt as it comes into contact with the pin when this is being done4 ,if the clock is not required to repeat1 the snail may be placed upon the center arbor1 instead of on a stud with a star wheel as shown1 and this is generally done with the cheaper class of hour striking clocks2 but the position of the snail is not then so definite1 owing to the backlash of the motion wheels1 so that it will not repeat correctly1 as the pin of the rack may fall on a slope of the snail and1 besides1 a smaller snail must be used1 unless it is brought out to clear the nose of the minute wheel cock1 or bridge if one be used4 ,illustration3 ,fig4 #ajd4 ,hour and half hour snail striking work with fusee train4 ,,half-,,hour ,,striking4--,the usual way of getting the clock to strike one at the half-hour1 is by making the first tooth of the rack1 ,c1 lower than the rest1 and placing the second pin in the minute wheel1 ,e1 a little nearer the center than the hour pin1 so that the rack hook1 ,b1 is lifted free of the first tooth only at the half hour4 ,but this adjustment is too delicate after some wear has occurred and the action is then liable to fail altogether or to strike the full hour1 from the pin getting bent or from uneven wear of the parts4 ,the arrangement shown in ,fig4 #ajd is generally used in ,english work1 as it is much safer4 ,one arm of a bell-crank lever rests on a cam fixed to the minute wheel1 ,e4 ,this arm is shaped so that just before the half-hour the other extremity of the bell-crank lever catches a pin placed in the rack1 ,c1 and permits it to release the train and fall the distance of but one tooth4 ,this is the position shown in ,fig4 #ajd4 ,after the half-hour has struck1 the cam carries the hook free from the pin in ,c4 ,illustration3 ,fig4 #aje4 ,rack1 showing method of getting sizes of snail steps according to distance from the rack center to the pin in the rack tail4 ,,division ,,of ,,the ,,hour ,,snail4--,the length of the rack tail1 from the center of the stud hole in the rack to the center of the pin1 should be equal to the distance between the center of the stud hole and the center of the snail4 ,the difference between the radius of the top and the radius of the bottom step of the snail may be obtained by getting the angular distance of twelve teeth of the rack from center to pin4 ,see ,a ,b1 ,c ,d1 ,e ,f1 ,fig4 #aje1 which show the total distances for twelve steps of the snail for rack tails of different lengths4 ,divide the circumference of a piece of brass into twelve parts and draw radial lines as shown in ,fig4 #ajf4 ,each of these spaces is devoted to a step of the snail4 ,draw circles representing the top and bottom step4 ,divide the distance1 ,a ,b or ,e ,f1 ,fig4 #aje1 between these two circles1 into eleven equal parts1 and at each division draw a circle which will represent a step of the snail4 ,the rise from one step to another should be sloped as shown1 so as to raise the pin in the rack arm if the striking train has been allowed to run down1 and it should be resting on the snail when it is desired to turn the hands back4 ,the rise from the bottom to the top step is bevelled off1 so as to push the pin in the rack arm on one side1 by springing the thin brass of the arm and allow it to ride over the snail if it is in the way when the clock is going4 ,it should also be curved to avoid interference with the pin4 ,clockmakers making new snails when repairing generally mark off the snail on the clock itself after the rest of the striking work is in position4 ,a steel pointer is fixed in the hole of the lower rack arm1 and the star wheel jumped forward twelve teeth 7one at a time7 by means of the pin in the motion wheel4 ,after each jump a line is marked on the blank snail with the pointer in the rack arm by moving the rack arm4 ,these twelve lines correspond to the twelve radial lines in ,fig4 #ajf4 ,the motion wheel is then turned sufficiently to carry the pin in it free of the star wheel and leave the star wheel and blank snail quite free on their stud4 ,the rack hook is placed in the first tooth of the rack1 and while the pointer in the rack arm is pressed on the blank snail1 the latter is rotated a little1 so that a curve is traced on it4 ,the rack hook is then placed in the second1 and afterwards in the succeeding teeth consecutively1 and the operation repeated till the twelve curves are marked4 ,there is one advantage in marking off the snail in this way4 ,should there be any inaccuracy in the division of the teeth of the rack1 the steps of the snail are thus varied to suit it4 ,this frequently occurs in old clocks which have had new racks filed up by hand by some watchmaker4 ,reference to the drawing1 ,fig4 #aje1 will show that the rack is laid out as a segment of a wheel with teeth occupying two degrees each1 with a few teeth added for safety4 ,fourteen to sixteen teeth are generally provided1 for the following reasons3 ,if the first tooth is used to strike the half hours1 it may in time become worn so that it can no longer be stretched to its proper length4 ,in such cases moving the pin two degrees nearer the rack teeth will allow us to use the teeth from the second to the thirteenth in striking twelve1 which makes a cheap and easy repair1 as compared to inserting a new tooth or making a new rack4 ,weight driven snail clocks should have the weight cords of the striking side long enough so that the striking train will not run down before the time train1 as in such a case the rack tail is pushed to one side by the progress of the snail 7which is carried on the time train and is still running72 then the rack will drop clear out of reach of the gathering pallet and when the striking train is wound that train will continue striking until it runs down1 or the dial is removed and the rack replaced in mesh with the gathering pallet4 ,this happens with short racks and with large1 old-fashioned snails4 ,by leaving a few more teeth in the rack the rack tail will strike the stud1 or hour wheel sleeve1 before the rack teeth get out of reach of the gathering pallet4 ,many watchmakers put a stud or pin in the plate to stop the rack from falling beyond the twelfth step1 to prevent troubles of this kind4 ,the rack tail is friction-tight on its arbor and should be adjusted so that the proper tooth shall come in mesh with the gathering pallet for each step of the snail1 or irregular striking will result4 ,such a clock may strike one1 two1 three and four correctly and then strike six for five1 or seven or nine for eight1 or thirteen for twelve1 or it may strike one or two hours wrong and the rest correctly4 ,this is because the gathering pallet1 ,f1 ,fig4 #ajd1 does not carry the rack teeth safely past the edge of the rack hook1 ,b1 owing to the tail of the rack not being properly adjusted4 ,the teeth should all be carried safely past the edge of the hook and then be dropped back a little as the hook engages2 this is the more necessary to watch with hand-made racks and snails1 or after putting in a new1 and therefore larger1 pin in the rack tail to replace one which is badly worn4 ,illustration3 ,fig4 #ajf4 ,laying out steps of snail4 ,the snail should be put on so that the pin in the rack tail will strike the center of each step1 or there is danger of irregular striking1 or of failure to strike twelve1 owing to the pin striking the surface of the cam midway between one and twelve and thus preventing the rack from falling the requisite number of teeth4 ,when this occurs the clock will jam and stop4 ,the rack hook1 ,b1 ,fig4 #ajd1 should be lifted far enough so that the rack will fall clear of the hook without the teeth catching and making a rattling noise as they pass the hook4 ,in many old hour strikes the first tooth of the rack is left longer than the rest to ensure this freedom of passage when the rack is released4 ,the gathering pallet1 ,f1 is the weakest member of the system and will be very likely to be split or worn out in clocks brought in for repair4 ,it should be squared on its arbor1 or pinned1 but many are not4 ,if split1 and the arbor is round1 where the pallet is put on1 it may cause irregular striking by opening on the arbor and permitting the train to run when the tail strikes the pin in the rack4 ,a new one should be made so as to lift one tooth and a very little of the next one at each revolution4 ,it is necessary to cause the gathering pallet to lift a little more than one tooth of the rack1 and let it fall back again1 to insure that one will always be lifted2 because if such was not the case the clock would strike irregularly1 and would also be liable sometimes to strike on continually till it ran down4 ,if the striking part is locked by the tail of the gathering pallet catching on a pin in the rack1 the tail should be of a shape that will best prevent the rack from falling back when the clock warns for striking the next hour2 and of course the acting faces of the pallet must be perfectly smooth and polished4 ,the teeth of the rack may require dressing up in some cases and to allow this to be done the rack may be stretched a little at the stem1 with a smooth-faced hammer1 on a smooth anvil2 or1 if it wants much stretching1 take the pene of the hammer and strike on the back1 with the front lying on the smooth anvil4 ,the point of the rack hook1 ,b1 will probably be much worn1 and when dressing it up it will be safe to keep to the original shape or angle4 ,the point of the rack hook is always broader than the rack1 and the mark worn in it will be about the middle of the thickness2 so enough will be left to show what the original shape or angle was4 ,after cleaning1 particularly if it be ,french1 look for dots on the rims of the wheels1 and for pinions with one end of one leaf filed off slantingly4 ,when putting it together1 place the pin wheel 7that is the one with the pins7 and the pinion it engages with so that the leaf of the pinion 7which you will find filed slanting at one extremity7 enters between the two teeth of the wheel1 opposite which you will find a countersunk mark1 on the side of the wheel4 ,see also that the gathering pallet1 ,f1 which lifts the rack1 does so at the same time that the gong hammer falls4 ,then place the hour and minute wheels and cannon pinion so that the countersunk marks on each line with each other4 ,neglect of the marks on a marked train generally means that you will have to take the clock down again and set it up properly before it will run2 therefore pay attention to these marks the first time4 ,,quarter ,,chiming ,,snail ,,strikes4--,fig4 #ajg shows the counting mechanism and trains of an ,english1 fusee1 quarter-strike work4 ,the time train occupies the center1 the hour striking train the left and the chiming train the right4 ,all the train wheels are between the plates and are dotted in as in ,fig4 #ajd1 while the counting mechanism is on the front plate1 behind the dial and is drawn in full lines1 to show that it is outside4 ,,going ,,train4 ,fusee ,wheel #if ,pinion #h ,center ,wheel #hd ,pinion #g ,third ,wheel #gh ,pinion #g ,,striking ,,train4 ,fusee ,wheel #hd ,pinion #h ,pin ,wheel1 #h pins in ,pin ,wheel #fd ,pinion #h ,pallet ,wheel #gj ,pinion #g ,warning ,wheel #fj ,fly ,pinion #g ,,chiming ,,train4 ,fusee ,wheel #ajj ,pinion #h ,second ,wheel #hj ,pinion #h ,pallet ,wheel #fd ,pinion #h ,chiming ,wheel #dj ,warning ,wheel #ej ,fly ,pinion #h ,the reader will see a marked resemblance between the hour and time trains of ,fig4 #ajd and the same trains of ,fig4 #ajg4 ,the hour rack hook in #ajg1 however1 is hung from the center and the hour warning lever is raised by a spring instead of a lifting piece4 ,the minute wheel of ,fig4 #ajg carries a snail of four steps1 corresponding to the four teeth of the quarter rack1 and the tail of the quarter rack is bent upwards towards the rack1 to engage with the quarter snail4 ,the quarter rack carries a pin which projects on both sides of the rack2 one side of this pin stops the tail of the quarter gathering pallet and therefore locks the train as fully described in ,fig4 #ajd4 ,the other side of the same pin acts on the tail of the hour warning lever1 so that whenever the quarter rack falls the hour warning lever is released and its spring moves it into the path of the hour warning pin4 ,this goes on whether the hour rack hook is released or not4 ,behind the quarter snail1 there are four pins in the minute wheel2 these pins raise the quarter lifting piece1 which raises the quarter rack hook and the quarter warning lever at the same time1 thus warning and dropping the quarter rack2 as soon as the lifting piece drops1 the warning lever and rack hook are released and the quarter train starts4 ,illustration3 ,fig4 #ajg4 ,quarter chiming snail strike1 ,english fusee movement4 ,illustration3 ,fig4 #ajh4 ,eight day snail half hour strike1 ,french system1 striking train locked4 ,one1 two1 three1 or four quarters are chimed according to the position of the quarter snail1 which turns with the minute wheel4 ,at the time for striking the hour 7when the quarter rack is allowed to fall its greatest distance71 the pin in it falls against the bent arm of the hour rack hook1 and releases the hour rack and hour warning lever4 ,as the last tooth of the quarter rack is gathered up1 the pin in the quarter rack pulls over the hour warning lever1 and lets off the hour striking train4 ,the position of the pieces in the drawing is as they would be directly after the hour was struck4 ,figs4 #ajh1 #aji and #aaj are three views of the ,new ,haven eight-day snail strike1 which is on the ,french system4 ,as nearly all ,american strikes utilize this system and the work is between the plates1 this may be considered a typical ,american snail strike4 ,as will be seen in ,fig4 #ajh1 by the two pins at the center arbor1 immediately behind the snail1 this is a half-hour strike2 and as the rack hook has for its lower step a little more than twice the depth of the other steps in the snail1 it will readily be perceived that this rack hook may be pushed almost out and thus release the train without dropping the rack4 ,this is the method pursued in striking half hours4 ,figs4 #aji and #aaj show the parts more clearly than in #ajh4 ,they are drawn a little larger than actual size and we will discover that the rack is the only portion of this system that works by gravity1 all the others being spring operated4 ,we see here the pins ,j ,k1 which are used to push out the lever ,m sufficiently far so that the upper portion1 which is bent at right angles to form a stop1 will free the warning pin ,o and allow the train to run4 ,the rack hook and the locking lever ,l are mounted on the same arbor and are kept in position by a coiled spring on the arbor until they are pushed out by the lower projection at the upper end of ,m for either the half-hour or hour strike4 ,as shown in ,fig4 #aji1 the lever ,m and the rack hook are pushed out by ,j far enough to pass the warning pin ,o and to unlock the train1 which is normally locked by the pin ,n and the lever ,l4 ,g is the gathering pallet1 which is a long pin in a lantern pinion as in the ordinary count wheel strike4 ,h is the hammer tail and ,p the pin wheel2 ,r is the rack and ,t the rack tail4 ,the rack arm is curved to pass the center arbor when dropping for twelve and the rack tail is bent toward the teeth in order that it may admit of a longer rack in a small movement1 thus permitting of a large snail and consequently less liability of disarrangement4 ,the same necessity of the proper adjustment of the rack tail ,t with the snail exists as has already been spoken of in regard to the ,english form of the snail strike4 ,in ,fig4 #aaj will be seen the rack dropped clear with the tail resting clear of the snail at one stroke from the snail4 ,in other words1 the train is now in position to give eleven more strokes1 having struck the first stroke of twelve4 ,by comparison with ,fig4 #aji1 it will be seen that the spring actuated arm ,m has been thrown forward so that its dog is resting on the center arbor1 after having been released from the hour pin ,k4 ,this holds ,m out of the way of the warning pin ,o and the rack hook and allows the parts to operate as fully described with the ,english rack4 ,the gathering pallet ,g must have as many teeth as there are teeth between the pins in the pin wheel ,p4 ,the train is locked by ,l coming in contact with ,n1 the locking pin on the wheel on the same arbor as the gathering pallet4 ,in setting this train up1 it should stop so that the warning pin ,o should be near the fly4 ,as all the parts are operated by springs on the arbor1 as shown by the hammer-spring ,h1 it will be seen that this strike mechanism will work in any position1 while that which is operated by gravity must be kept upright4 ,a loose fly will cause the clock to strike too fast and may cause it to strike wrong4 ,careless adjustment of the rack tail ,t with the snail will also induce wrong counting1 although this is somewhat easier to adjust than the ,english form of strike4 ,the hook should safely clear the rack teeth just as the gathering pallet ,g lets go of a tooth4 ,if attention is paid to this point in adjusting the rack tail there will generally be little trouble4 ,illustration3 ,fig4 #aji4 ,train about to strike the half hour2 the hook ,l free of the train1 which is held by the warning pin ,o2 one stroke will be given when ,m drops4 ,the cam bearing the pins ,j ,k on the center arbor may be shifted with a pair of pliers to secure accurate register of hands and strike1 as is the case with most ,american strikes4 ,in putting in the pin wheel it should be set so that the pins may have a little run before striking the hammer tail1 as this hammer tail is very short1 and if the spring is strong the pins may not be able to lift the hammer tail without sufficient run to get the train thoroughly under motion4 ,the half-hour strike should also be tested so that the pin ,j will release the warning pin ,o from the lever ,m without releasing the rack hook from the rack1 as shown in ,fig4 #aji4 ,the parts of the train when at rest will be readily discerned in ,fig4 #ajh1 where the hook ,l has locked the train by the pin ,n and the freedom between the pins and the hammer tail is about what it should be4 ,illustration3 ,fig4 #aaj4 ,train unlocked and running4 ,note position of ,l and ,m4 ,the relative position of the locking lever ,l and the rack hook is also very clearly shown in ,fig4 #ajh2 that is1 when the rack hook is pressed clear home at the lower notch of the rack1 the lever ,l should safely lock the train and the lever ,m be resting with its link against the center arbor4 ,,chapter ,,xix4 ,,the ,,construction ,,of ,,simple ,,and ,,perpetual ,,calendars4 ,in taking up the study of calendar work the first thing that the student observes is the irregularity of motion of the various members4 ,every other portion of a clock has for its main object the attainment of the nicest regularity of motion1 while the calendar must necessarily have irregular motion4 ,the hand of the day of the month proceeds around its dial regularly from #a to #bh and then jumps to #a in ,february of some years1 while it continues to #bi in others2 sometimes it revolves regularly from #a to #ca for several revolutions and then jumps from #cj to #a4 ,what is the reason of this8 ,if the moon's phases are shown they do not agree with the changes of the month wheels1 but keep gaining on them1 while if an 8equation of time0 is shown1 we have a hand that moves irregularly back and forth from the ,figure ,,xii at the center of its dial4 ,what is the cause of this gaining and losing8 ,in order to understand this mechanism properly we shall have to first know what it is intended to show and this brings us to the study of the various kinds of calendar4 ,the earth revolves about its axis with a circular motion2 it revolves about the sun with an elliptical motion4 ,this means that the earth will move through a greater angular distance1 measured from the sun's center1 in a given time at some portions of its journey than it will do at others2 at times the sun describes an arc of #eg minutes of the ecliptic2 at other times an arc of #fa minutes in a day2 hence the sun will be directly over a given meridian of the earth 7noon7 a little sooner at some periods than at others4 ,now the time at which the sun is directly over the given meridian is apparent noon1 or solar noon4 ,as before stated1 this is irregular1 while the motion of our clocks is regular1 consequently the sun crosses the meridian a little before or a little after twelve by the clock each day1 varying from #ae minutes before twelve to #ae minutes after twelve by the clock4 ,the best we can do under these circumstances is to divide these differences of gaining or losing1 take the average or mean of them and regulate the clock to keep mean time4 ,here then we have two times--the irregular apparent time and the regular mean apparent time4 ,the amount to be added to or subtracted from the mean in order to get the solar or actual apparent time is called the equation of time and this is shown by the equation hand on an astronomical or perpetual calendar clock4 ,the moon revolves on its axis with a circular motion and it revolves about the earth with an elliptical motion1 the earth being at one focus of the ellipse2 as this course does not agree with that of the sun1 but is shorter1 it keeps gaining so that the lunar months do not agree with the solar4 ,certain stars are so far away that they apparently have no motion of their own and are called fixed2 hence in observing them the only motion we can discern is the circular motion of the earth4 ,we can set our clocks by watching such stars and a complete revolution of the earth1 measured by such a star1 is called an astronomical or sidereal day4 ,this is the one used in computing all our time4 ,it is shorter than the mean solar day by #c minutes #ef seconds4 ,a year is defined as the period of one complete revolution of the earth about the sun1 returning to the same starting point in the heavens4 ,by taking different starting points we are led to different kinds of years4 ,the point generally taken is the vernal equinoctial point1 and when measured thus it is called the tropical year1 which gives us the seasons4 ,it is #bj minutes shorter than the siderial year4 ,a siderial year is the period of a complete revolution of the earth about the sun4 ,this period is very approximately #cfe days1 #f hours1 #i minutes1 #i4e seconds of mean time4 ,here we see an important difference between the siderial and the civil year of #cfe days1 and it is this difference1 which must be accounted for somehow1 that causes the irregularities in our calendar work4 ,for ordinary and business purposes the public demands that the year shall contain an exact number of days and that it should bear a simple relation to the recurrence of the seasons4 ,for this reason the civil year has been introduced4 ,the ,roman emperor1 ,julius ,caesar1 ordered that three successive years should have #cfe days each and the fourth year should have #cff days4 ,the fourth year1 containing #cff days1 is called a leap year1 because it leaps over1 or gains1 the difference between the civil and siderial time of the preceding three years4 ,for convenience the leap year was designated as any year whose number is exactly divisible by #d4 ,this is called the ,julian calendar4 ,but as a siderial year is #cfe days1 #f hours1 #i minutes1 #i4e seconds of mean time1 the addition of one day of twenty-four hours would not exactly balance the two calendars2 therefore ,pope ,gregory ,,xiii41 in #aehb1 ordered that every year whose number is a multiple of #ajj shall be a year of #cfe days1 unless the number of the year is divisible by #djj1 when it shall be a leap year of #cff days4 ,the calendar constructed in this way is called the ,gregorian calendar1 and is the one in common use4 ,its error is very small and will amount to only #a day1 #e hours1 #cj minutes in #d1jjj years4 ,the revolution of the moon around the earth in relation to the stars1 takes place in #bg days1 #g hours and #dc minutes this is called a siderial month4 ,but during this period the earth has advanced along the plane of its path about the sun and the moon must make up this distance in order to return to the same point in relation to the sun4 ,this period is called a synodic month4 ,its average length is #bi days1 #ab hours1 #dd minutes1 #b4i seconds4 ,having now understood these differences we shall be able to intelligently examine the various calendar mechanisms on the market and understand the reasons for their apparent departures from regular mechanical progression1 as the equation of time gives us the difference between real and mean apparent1 or solar time2 we regulate our clocks by means of siderial time2 the irregular procession of #cj and #ca days makes the civil calendar agree with the seasons1 or the tropical year1 and the remainder of the discrepancy between civil and siderial time is made up in ,february at the period when it is of the least consequence4 ,,simple ,,calendar ,,work4--,fig4 #aaa shows the ,american method of making a simple calendar1 the example shown being drawn from a movement of the ,waterbury ,clock ,company as a typical example4 ,no attempt is made here to show the day of the week or the month4 ,the days of the month are shown by a series of numbers from #a to #ca1 arranged concentrically with the time dial and the current day is indicated by a hand of different color1 carried on a pipe outside the pipe of the hour hand on the center arbor4 ,illustration ,illustration3 ,fig4 #aaa4 ,simple calendar on time train4 ,illustration3 ,fig4 #aab4 ,calendar work for grandfather clocks4 ,in order to accomplish this the motion work for the hands is mounted inside the frames1 the hour pipe and center arbor being suitably lengthened4 ,in the ,figure ,a is the cannon pinion2 ,b1 the minute wheel2 ,c1 the minute pinion2 ,d1 the hour wheel at the rear end of the hour pipe2 this pipe projects through the frame and forms a bearing in the frame for the center arbor4 ,friction-tight on the hour pipe1 in front of the front plate1 is the pinion ,e1 which drives a wheel ,f of twice as many teeth4 ,this wheel ,f is mounted loosely on a stud and has a pin which meshes with the teeth of a ratchet wheel ,g4 ,g is carried at the bottom end of a pipe which fits loosely on the hour pipe and carries the calendar hand ,h under the hour hand and close to the dial4 ,the pinion on the hour pipe revolves once in twelve hours4 ,the wheel ,e has twice as many teeth and will therefore revolve once in twenty-four hours4 ,it moves the ratchet ,g one tooth at each revolution2 therefore the hand ,h moves one space every twenty-four hours4 ,there are #ca teeth1 so that the hand must be set forward every time it reaches the #bhth and #bith of ,february and the #cjth of ,april1 ,june1 ,september and ,november4 ,this is the simplest and cheapest of all the calendars1 occupies the least space and is frequently attached to nickel alarm clocks for that reason4 ,a simple calendar work often met with in old clocks of ,european origin is shown in ,fig4 #aab4 ,gearing with the hour wheel is a wheel1 ,a1 having twice its number of teeth1 and turning therefore once in twenty-four hours4 ,a three-armed lever is planted just above this wheel2 the lower arm is slotted and the wheel carries a pin which works in this slot1 so that the lever vibrates to and fro once every twenty-four hours4 ,the three upper wheels1 ,b1 ,c and ,d in the drawing1 represent three star wheels4 ,b has seven teeth1 corresponding to the days of the week2 ,c has #ca teeth1 for the days of the month2 and ,d has #ab teeth1 for the months of the year4 ,each carries a hand in the center of a dial on the other side of the plate4 ,every time the upper arms of the lever vibrate they move forward the day of the week1 ,b1 and the day of the month1 ,c1 wheels each one tooth4 ,the extremities of the two upper levers are jointed so as to yield on the return vibration1 and are brought into position again by a weak spring4 ,there is a pin in the wheel1 ,c1 which1 by pressing on a lever once every revolution1 actuates the month of the year wheel1 ,d4 ,this last lever is also jointed1 and is pressed on by a spring so as to return to its original position4 ,each of the star wheels has a click kept in contact by means of a spring4 ,for months with less than #ca days1 the day of the month hand has to be shifted forward4 ,,perpetual ,,calendar ,,work4--,figs4 #aac1 #aad1 #aae1 show a perpetual calendar which gives the day of the week1 day of the month and the month1 making all changes automatically at midnight1 and showing the #ca days on a dial beneath the time dial1 by means of a hand1 and the days of the week and the month by means of cylinders operating behind slots in the dial on each side of the center4 ,this is also a ,waterbury movement4 ,illustration3 ,fig4 #aac4 ,perpetual ,calendar ,movement4 ,a pinion on the hour pipe engages a wheel1 ,a1 having twice the number of teeth and mounted on an arbor which projects through both plates4 ,the rear end of this arbor carries a cam1 ,b1 on which rides the end of a lever1 ,c1 which is pivoted to the rear frame4 ,the lever is attached to a wire1 ,d1 which operates a sliding piece1 ,e1 which is weighted at its lower end4 ,the cam1 which1 of course1 revolves once in twenty-four hours1 drops its lever at midnight and the weight on ,e pulls it down4 ,e bears a spring pawl1 ,f1 which on its way down1 raises the spring actuated retaining click1 ,h1 and then moves the #ca-toothed wheel ,g one notch4 ,this wheel is mounted on the arbor which carries the hand and1 of course1 advances the hand4 ,lying on top of the wheel1 ,g1 is a cam1 ,i1 pivoted to ,g near its circumference and having an arm reaching toward the months cylinder and another reaching towards the right leg of the pawl1 ,h1 while it is cut away in the center1 so as to clear the center arbor carrying the hand4 ,trace this cam1 ,i1 carefully in ,figs4 #aac and #aad1 as its action is vital4 ,the lower arm of this cam is shown more clearly in ,fig4 #aad4 ,it projects above the wheel and engages the long teeth1 ,j1 and the cam1 ,k1 mounted on the year cylinder arbor2 where the lower arm of ,i strikes one of these teeth it shoves the upper arm outward1 so that it strikes the retaining end of the pawl1 ,h1 and holds it up1 and the descending pawl1 ,f1 may then push the wheel1 ,g1 forward for more than one tooth4 ,the upper end of ,i is broad enough to cover three teeth of the wheel1 ,g1 when pushed outward1 and the slot in ,e is long enough so that ,f may descend far enough to push ,g forward three teeth at once1 unless it is stopped by ,h falling into a tooth1 so that the position of ,i1 when it is holding up ,h and the extra drop thus given to ,e serve to operate the jumps of #cj to #a1 #bh to #a and #bi to #a of the hand on the dial4 ,the teeth1 ,j1 ,fig4 #aad1 operate for two notches1 thus making the changes from #cj to #a4 ,the wide tooth1 ,m1 and cam1 ,k1 acting together1 make the change for ,february from #bh to #ca4 ,the #bith day is added by the movement of the cam1 ,k1 narrowing the acting surface once in four years1 as follows3 ,illustration3 ,fig4 #aad4 ,the months change gear4 ,looking at ,fig4 #aad we see an ordinary stop works finger1 mounted on the months arbor and engaging a four-armed maltese cross on the wheel4 ,behind the wheel is a circular cam 7shown dotted in7 with one-fourth of its circumference cut away2 the pivot holds the cam and cross rigidly together while permitting them to revolve loosely in the wheel4 ,the cam1 ,k1 lies close to the wheel and is pressed against the cam on the cross by a spring1 so that ordinarily the full width of ,m and ,k act as one piece on the end of the cam1 ,i1 which thus is pressed against the retaining pawl1 ,h1 during the passage of three teeth1 making the jump from #bh to #a each of these three years4 ,the fourth revolution of the maltese cross brings the cut portion of its cam to operate on ,k and allows ,k to move behind ,m1 thus narrowing the acting surface so that ,i only covers two teeth 7#cj and #ca7 for every fourth revolution of the month's cylinder1 thus making the leap year every fourth year4 ,the months cylinder is kept in position by the two-armed pawl1 ,n1 engaging the teeth1 ,l1 which stand at #ij degrees from the wheel1 as shown in ,fig4 #aac4 ,attached to the bearing for the week cylinder 7not shown7 is one revolution of a screw track1 or worm1 surrounding the arbor for the hand4 ,attached to the arbor is a finger1 ,o1 held taut by a spring and engaging the track1 ,p4 ,the revolution of the arbor raises ,o on ,p until it slips off1 when ,o1 drawn downward by its spring1 raises the pawl1 ,n1 drops on one of the teeth1 ,l1 and revolves the cylinder one notch4 ,q is a shifter for raising the pawl1 ,h1 and allowing the hand to be set4 ,illustration3 ,fig4 #aae4 ,the weeks change gear4 ,fig4 #aae shows the inner end of the cylinder for the days of the week4 ,there are two sets of these and fourteen teeth on the sprocket1 ,r1 so as to get the two cylinders approximately the same size 7there being #ad days and #ab months on the respective cylinders74 ,s is a pawl whose upper end is forked so as to embrace a tooth and hold the cylinder in position4 ,t is a hook1 carried on the sliding piece1 ,e1 which swings outward in its upward passage as ,e is raised and on its downward course raises the pawl1 ,s1 and revolves the sprocket1 ,r1 one tooth1 thus changing the day of the week at the same time the hand is advanced4 ,to set the calendar1 raise the pawl1 ,n1 and revolve the year cylinder until ,m and ,k are at their narrowest width2 that is1 a leap year4 ,then give the year cylinder as many additional turns as there are years since the last leap year1 stopping on the current month of the current year4 ,for instance1 if it is two years and four months since the #bith of ,february last occurred1 give the cylinder #b and _/ turns which should bring you to the current month1 raise the shifter1 ,q1 and set the hand to the current day4 ,then raise the pawl1 ,s1 and set the week cylinder to the current day4 ,place the hour hand on the movement so that the cam will drop ,e at midnight4 ,fig4 #aaf shows the dial of ,brocot's calendar work1 which1 with or without the equation of time and the lunations1 is to be met with in many grandfather1 hall and astronomical clocks4 ,we will assume that all of these features are present1 in order to completely cover the subject4 ,it consists of two circular plates of which the front plate is the dial and the rear plate carries the movement1 arranged on both sides of it4 ,all centers are therefore concentric and we have marked them all with the same letters for better identification in the various views as the inner plate is turned about to show the reverse side1 thus reversing the position of right to left in one view of the inner plate4 ,fig4 #aag shows the wheel for the phases of the moon1 which is mounted on the outside of the inner plate immediately behind the opening in the dial4 ,the dark circles have the same color as the sky of the dial and the rest is gilt1 white or cream color to show the moon as in ,fig4 #aaf4 ,the position of this plate is also shown in ,fig4 #abj4 ,by the dotted circles1 about the center ,d4 ,illustration3 ,fig4 #aaf4 ,dial of ,brocot's ,calendar4 ,the inner side containing the mechanism for indicating the days of the week and the days of the month is shown in ,fig4 #aah4 ,the calendar is actuated by means of a pin1 ,c1 fixed to a wheel of the movement which turns once in twenty-four hours in the manner previously described with ,fig4 #aac4 ,two clicks1 ,g and ,h1 are pivoted to the lever1 ,m4 ,g1 by means of its weighted end1 see ,fig4 #aai1 is kept in contact with a ratchet wheel of #ca teeth1 and ,h with a ratchet wheel of #g teeth4 ,as a part of these clicks and wheels is concealed in ,fig4 #aah1 they are shown separately in ,fig4 #aai4 ,when the lever1 ,m1 is moved to the left as far as it will go by the pin1 e1 the clicks1 ,g and ,h1 slip under the teeth2 their beaks pass on to the following tooth2 when e has moved out of contact the lever1 ,m1 falls quickly by its own weight1 and makes each click leap a tooth of the respective wheels1 ,b of #g and ,a of #ca teeth4 ,the arbors of these wheels pass through the dial 7,fig4 #aaf71 and have each an index which1 at every leap of its own wheel1 indicates on its special dial the day of the week and the day of the month4 ,a roll1 or click1 kept in position by a sufficient spring1 keeps each wheel in its place during the interval of time which separates two consecutive leaps4 ,this motion clearly provides for the indication of the day of the week1 and would be also sufficient for the days of the month if the index were shifted by hand at the end of the short months4 ,to secure the proper registration of the months of #cj days1 for ,february of #bh during three years1 and of #bi in leap year1 we have the following provision3 ,the arbor1 ,a1 of the day of the month wheel goes through the circular plate1 and on the other side is fixed 7see ,fig4 #abj7 a pinion of #aj leaves4 ,this pinion1 by means of an intermediate wheel1 ,i1 works another wheel 7centered at ,c7 of #abj teeth1 and consequently turning once in a year4 ,the arbor of this last wheel bears an index indicating the name of the month1 ,g1 ,fig4 #aaf4 ,the arbor1 ,c1 goes through the plate1 and at the other end1 ,c1 ,fig4 #aah1 is fixed a little wheel gearing with a wheel having four times as many teeth1 and which is centered on a stud in the plate at ,f4 ,this wheel is partly concealed in ,fig4 #aah by a disc ,v1 which is fixed to it1 and with the wheel makes one turn in four years4 ,on this disc1 ,v1 are made #bj notches1 of which the #af shallowest correspond to the months of #cj days2 a deeper notch corresponds to the month of ,february of leap year1 and the last three deepest to the month of ,february common years in each quarternary period4 ,the uncut portions of the disc correspond to the months of #ca days in the same period4 ,the wheel1 ,a1 of #ca teeth1 has a pin 7i7 placed before the tooth which corresponds to the #bhth of the month4 ,on the lever1 ,m1 is pivoted freely a bell-crank lever 7,n71 having at the extremity of the lower arm a pin 7o7 which leans its own weight upon the edge of the disc1 ,v1 or upon the bottom of one of the notches1 according to the position of the month1 and the upper arm of ,n is therefore higher or lower according to the position of the pin1 o1 upon the disc4 ,illustration3 ,fig4 #aag4 ,dial of ,moon's ,phases4 ,illustration3 ,fig4 #aah4 ,brocot's ,calendar2 ,rear ,view of ,calendar ,plate showing ,four ,year ,wheel and ,change ,mechanism4 ,illustration3 ,fig4 #aai4 ,change ,mechanism behind the ,four ,year ,wheel in ,fig4 #aah ,it will be easy to see that when the pin1 o1 rests on the contour of the disc the upper arm1 ,n1 of the bell-crank lever is as high as possible1 and out of contact with the pin as it is dotted in the figure1 and then the #ca teeth of the month wheel will each leap successively one division by the action of the click1 ,g1 as the lever1 ,m1 falls backward till the #cast day4 ,but when the pin1 o1 is in one of the shallow notches of the plate1 ,v1 corresponding to the months of #cj days1 the upper arm1 ,n1 of the bell-crank lever will take a lower position1 and the inclination that it will have by the forward movement of the lever1 ,m1 will on the #cjth bring the pin1 i1 in contact with the bottom of the notch1 just as the lever1 ,m1 has accomplished two-thirds of its forward movement1 so the last third will be employed to make the wheel #ca advance one tooth1 and the hand of the dial by consequence marks the #cast1 the quick return of the lever1 ,m1 as it falls putting this hand to the #ast by the action of the click1 ,g4 ,if we suppose the pin1 o1 is placed in the shallowest of the four deep notches1 that one for ,february of leap year1 the upper end of the arm1 ,n1 will take a position lower still1 and on the #bith the pin1 i1 will be met by the bottom of the notch1 just as the lever has made one-third of its forward course1 so the other two-thirds of the forward movement will serve to make two teeth of the wheel of #ca jump4 ,then the hand of the dial1 ,a1 ,figs4 #aaf and #aah1 will indicate #ca1 and the ordinary quick return of the lever1 ,m1 with its detent1 ,g1 will put it to the #ast4 ,lastly1 if1 as it is represented in the figure1 the pin1 o1 is in one of the three deepest notches1 corresponding to the months of ,february in ordinary years1 the pin will be in the bottom of the notch on the #bhth just at the moment the lever begins its movement1 and three teeth will pass before the return of the lever makes the hand leap from the #cast to the #ast4 ,the pin1 o1 easily gets out of the shallow notches1 which1 as will be seen1 are sloped away to facilitate its doing so4 ,to help it out of the deeper notches there is a weighted finger 7j7 on the arbor of the annual wheel4 ,this finger1 having an angular movement much larger than the one of the disc1 ,v1 puts the pin1 o1 out of the notch before the notch has sensibly changed its position4 ,,phases ,,of ,,the ,,moon4--,the phases of the moon are obtained by a pinion of #aj1 ,fig4 #abj1 on the arbor1 ,b1 which gears with the wheel of #hd teeth1 fixed on another of #ge1 which last gears with a wheel of #aac1 making one revolution in three lunations4 ,by this means there is an error only of 4#jjjjh day per lunation4 ,on the wheel of #aac is fixed a plate on which are three discs colored blue1 having between them a distance equal to their diameter1 as shown in ,fig4 #aag1 these discs slipping under a circular aperture made in the dial1 produce the successive appearance of the phases of the moon4 ,,equation ,,of ,,time4--,on the arbor of the annual wheel1 ,c1 ,figs4 #aaf1 #aah1 #abj1 is fixed a brass cam1 ,y1 on the edge of which leans the pin1 s1 fixed to a circular rack1 ,r4 ,this rack gears with the central wheel1 ,k1 which carries the hand for the equation4 ,that hand faces ,,xii the #aeth of ,april1 #adth of ,june1 #ast of ,september and the #beth of ,december4 ,at those dates the pin1 s1 is in the position of the four dots marked on the cam1 ,y4 ,the shape of the cam1 ,y1 must be such as will lead the hand to indicate the difference between solar and mean time1 as given in the table of the ,nautical almanac4 ,to set the calendar first see that the return of the lever1 ,m1 be made at the moment of midnight4 ,to adjust the hand of the days of the week1 ,b1 look at an almanac and see what day before the actual date there was a full or new moon4 ,if it was new moon on ,thursday1 it would be necessary1 by means of a small button fixed at the back1 on the arbor of the hand of the wheel1 ,b1 of the week1 to make as many returns as requisite to obtain a new moon1 this hand pointing to a ,thursday2 afterward bring back the hand to the actual date1 passing the number of divisions corresponding to the days elapsed since the new moon4 ,to adjust the hand of the day of the month1 ,a1 see if the pin1 o1 is in the proper notch4 ,if for the leap year1 it is in the month of ,february in the shallowest of the four deep notches 7o72 if for the same month of the first year after leap year1 then the pin should be1 of course1 in the notch1 ,i1 and so on4 ,illustration3 ,fig4 #abj4 ,brocot's ,calender3 ,wheels and ,pinions under the ,dial with their ,number of ,teeth4 ,,chapter ,,xx4 ,,hammers1 ,,gongs ,,and ,,bells4 ,just as the tone of a piano depends very largely upon the condition of the felts on the hammers which strike the wires1 so does the tone of a clock gong or bell depend on its hammer action4 ,the deep1 soft1 resonant tone in either instance depends on the vibration being produced by something softer than metal4 ,ordinarily this condition is reached by facing the hammer with leather4 ,the second essential is that the hammer shall immediately rebound1 clear of the bell1 so as not to interfere with the vibrations it has set up in the bell1 wire or tube4 ,as the leather gets harder the tone becomes harsher and 8tinny10 sometimes changing to another much higher tone and entirely destroying the harmony4 ,the remedy is either to oil the leather on the hammers1 or if they are much worn to substitute new and thicker leathers until the tone is sufficiently mellowed1 so that a vigorous blow will still produce a mellow tone of sufficient carrying power4 ,a piece of round leather belting will be found very convenient for this purpose4 ,the superiority of a chiming clock lies in its hammer action4 ,if this mechanism is not perfect1 only inferior results can be obtained4 ,the perfect hammer is the one that acts with the smallest strain and is operated with the least power4 ,heavy weights create a tremendous strain on the mechanism and bring disastrous results when one of the suspending cords break4 ,the method of lifting the hammer is one of importance1 and the action of the hammer-spring is but seldom right on old clocks brought in for repairs1 especially if it be a spring bent over to a right angle at its point4 ,if there are two springs1 one to force the hammer down after the clock has raised it up1 and another shorter one1 fastened on to the pillar1 to act as a counter-spring and prevent the hammer from jarring on the bell1 there will seldom be any difficulty in repairing it2 and the only operation necessary to be done is to file worn parts1 polish the acting parts1 set the springs a little stronger1 and the thing is done4 ,but if there is only one spring some further attention will be necessary1 because the action of the one spring answers the purpose of the two previously mentioned1 and to arrange it so that the hammer will be lifted with the greatest ease and then strike on the bell with the greatest force1 and without jarring1 requires some experience4 ,that part of the hammer-stem which the spring acts on should never be filed or bent beyond the center of the arbor1 as is sometimes done1 because in such a case the hammer-spring has a sliding motion when it is in action1 and some of the force of the spring is thereby lost4 ,the point of the spring should also be made to work as near to the center of the arbor as it is possible to get it1 and the flat end of the spring should be at a right angle with the edge of the frame1 and that part of the hammer-stem that strikes against the flat end of the spring should be formed with a curve that will stop the hammer in a particular position and prevent it jarring on the bell4 ,this curve can only be determined by experience2 but a curve equal to a circle six inches in diameter will be nearly right4 ,the action of the pin wheel on the hammer tail is also of importance4 ,the acting face of the hammer tail should be in a line with the center of the pin wheel1 or a very little above it1 but never below it1 for then it becomes more difficult for the clock to lift the hammer1 and the hammer tail should be of such a length as to drop from the pins of the pin wheel1 and when it stops be about the distance of two teeth of the wheel from the next pin4 ,this allows the wheel-work to gain a little force before lifting the hammer1 which is sometimes desirable when the clock is a little dirty or nearly run down4 ,we might also mention that in setting the hammer-spring to work with greater force it is always well to try and stop the fly with your finger when the clock is striking1 and if this can be done it indicates that the hammer spring is stronger than the striking power of the clock can bear1 and it ought to be weakened1 because the striking part will be sure to stop whenever the clock gets the least dirty4 ,gong wires are also the cause of faulty tones4 ,in the factories these are made by coiling wires of suitable lengths and sections on arbors in a lathe4 ,they are then heated to a dull red and hardened by dipping in water or oil4 ,after cooling they are trued in the round and the flat like a watch hairspring and then drawn to a blue temper4 ,the tone comes with the tempering1 and if they are afterwards bent beyond the point where they will spring back to shape the tone is interfered with4 ,many repairers1 not being aware of this fact1 have ruined the tone of a gong wire while trying to true it up by bending with pliers4 ,when the owner is particular about the tone of the clock1 a new gong should always be put in if the old one is badly bent4 ,the wires are soldered to their centers and if they are at all loose they should be refastened in the same manner if it can be done without drawing the temper of the wire4 ,when this cannot be done a plug of solder may be driven in between the wire and the side of the hole so as to stop all vibration or the solder already in place may be driven down so as to make all tight1 as any vibration at this point will interfere with the tone4 ,illustration3 ,fig4 #aba4 ,the pins in the chiming barrels4 ,,tuning ,,the ,,bells4--,bells only very slightly out of tone offend the musical ear1 and they may easily be corrected to the extent of half a tone4 ,to sharpen the tone make the bell shorter by turning away the edge of it if it be a shell1 or by cutting off if it be a rod or tube2 to flatten the tone1 thin the back basin-shaped part of the bell by turning some off the outside4 ,bells which are cracked give a poor sound because the edges of the crack interfere with each other when vibrating4 ,they may be repaired by sawing through the crack to the end of it1 so that the edges will not touch each other when vibrating4 ,if there is danger of the crack extending further into the bell1 first drill a round hole in the solid metal just beyond the end of the crack1 and then saw through into the hole2 this will generally prevent any further trouble4 ,,marking ,,the ,,chime ,,barrel4--,the chime barrel in small clocks is of brass and should be as large in diameter as can be conveniently got in4 ,to mark off the positions of the pins for the ,cambridge chimes1 first put the barrel in the lathe and trace circles round the barrel at distances apart corresponding to the positions of the hammer tails4 ,there are five chimes of four bells each for every rotation of the barrel1 and a rest equal to two or three notes between each chime4 ,assuming the rest to be equal to three notes1 divide the circumference of the barrel into thirty-five equal parts by means of an index plate1 and draw lines at these points across the barrel with the point of the tool by moving it with the slide rest screw4 ,call the hammer for the highest note ,d1 and that for the lowest note ,f4 ,then the first pin is to be inserted where one of the lines across the barrel crosses the first circle2 the second pin where the next line crosses the second circle2 the third pin where the third line crosses the third circle and the fourth pin where the fourth line crosses the four circle1 because the notes of the first chime are in the order1 ,d1 ,c1 ,bb1 ,f4 ,then miss three lines for the rest4 ,the first note of the second chime is ,bb and the pins for it will consequently be inserted where the first line after the rest crosses the third circle1 and so on4 ,where two or more notes on the same bell come so close as to make it difficult to strike them properly1 it is usual to put in another hammer1 as it shown in ,fig4 #aba1 where there are two ,fs4 ,in fine clocks the pins are of varying lengths so as to strike the hammers on the bells with varying force and thus give more expression to the music4 ,the following gives the ,cambridge ,chimes1 which are used in the ,westminster ,great ,clock4 ,they are founded on a phrase in the opening symphony of ,handel's air1 8,i know that my ,redeemer liveth10 and were arranged by ,dr4 ,crotch for the clock of ,great ,st4 ,mary's1 ,cambridge1 in #agic4 ,illustration3 ,fig4 #abb4 ,westminster chimes4 ,in ,europe these chiming clocks are sometimes very elaborate1 as the following description of a set of bells in ,belgium will show3 8,so far as the experience of the writer goes the ,belgian carillons are invariably constructed on one prevailing plan1 with the exception that the metal used for the cylinder is generally brass2 here1 however1 it is of steel1 and consists of a large barrel measuring #d feet #b inches in width and #c feet #f inches in diameter1 its surface being pierced with horizontal lines of small square holes about inch square4 ,there are lines of #fj of these in the width of the barrel1 while there are #abj lines of them round the circumference1 making a total of #g1bjj holes4 ,the drilling of these1 of course1 takes place when the cylinder is made1 and1 so far as this part is concerned1 the barrel is complete before it is brought to the tower4 8,into these square holes are fixed the #8pins1' adjusted on the inside of the cylinder by nuts4 8,the pins are of steel of finely graduated sizes1 corresponding with the value of the notes of music4 ,some idea of the precision obtainable may be gathered by the fact1 as the carillonneur told the writer1 that there were no less than #bd grades of pins1 so as to insure the greatest accuracy of striking the bells4 8,over the cylinder are #fj steel levers with steel nibs2 these are lifted by the #8pins' and1 connected by wires with the hammers1 strike the bells4 8,the #ce bells are furnished with #gb hammers1 which are fixed as ordinary clock-hammers outside of the bells2 three of the bells 7in the ring of eight7 have a single hammer only1 the limited space in the #8cage' making it impossible to put more1 while others are supplied with two or three apiece for use in rapidly repeating notes of the music4 ,on a visit some years ago to the carillon at ,malines1 the writer noticed that some of the bells there had no less than five hammers apiece4 8,obviously1 though there are #gb hammers in connection with the carillon1 only #fj1 corresponding with the number of levers1 can be used at one time2 these are selected according to the requirement of the tune2 in case of new tunes1 the wires can easily be adjusted so as to bring other hammers and bells into use4 8,the feature of the ,belgian carillons is that instead of the single notes of the air being struck as with the old familiar #8chimes' harmonized tunes of great intricacy are rendered with chords of three1 four or even five bells striking at one time4 8,the cylinder here is capable of #abj #8measures' of music1 but as1 a matter of fact it is subdivided so that half a revolution plays every hour4 8,a march is1 as a rule1 played at the odd hours1 and the national air at the even1 but the bells are silent after #i p4 m4 and start again at #h a4 m4 8,the motive power is supplied by a weight of #h cwt41 and is controlled by a powerful fly of four fans artistically formed to represent swans4 ,it may be mentioned that the keyboard for hand-playing consists of thirty-five keys of wood and eleven pedals2 these1 as indeed the whole apparatus of this part1 are entirely separate from the automatic carillon2 in this instance the keys connect with the clappers of the bells and have no association with the hammers4 ,the pedals are connected with the eleven largest bells and are supplementary to the hour key40 ,,tubular ,,chimes are tubes of bell metal1 cut to the proper lengths to secure the desired tones and generally1 but not always1 nickel plated4 ,as they take up much room in the clock1 they are generally suspended from hooks at the top of the back board of the case1 being attached to the hooks by loops of silk or gut cords1 passed through holes drilled in the wall of the tubes near the top ends4 ,the hour tube1 being long and large1 generally extends nearly to the bottom of a six-foot case1 while the others range upwards1 shortening according to the increase of pitch of the notes which they represent4 ,this makes it necessary to place the movement on a seat board and hang the pendulum from the front plate of the movement1 so that such clocks have1 as a rule1 comparatively light pendulums4 ,on account of the position and the great spread of the tubes1 the chiming cylinder and hammers are placed on top of the movement1 parallel with the plates1 and operated from the striking train by means of bevel gears or a contrate wheel4 ,the hammers are placed vertically on spring hammer stalks and connected with the chiming cylinder levers by silken cords4 ,this gives great freedom of hammer action and results in very perfect tones4 ,the hammers must of course be each opposite its own tube and thus they are rather far apart1 which necessitates a long cylinder4 ,this gives room for several sets of chimes on the same cylinder if desired1 as a very slight horizontal movement of the cylinder would move the pins out of action with the levers and bring another set into action or cause the chimes to remain silent4 ,practically all of the manufacturers of 8hall0 or chiming clocks import the movements and supply ,american cases1 hammers and bells4 ,the reason is that there is so little sale for them 7from a factory standpoint7 that one factory could supply the world with movements for this class of clocks without working overtime1 and therefore it would be useless to make up the tools for them when they can be bought without incurring that expense4 ,,chapter ,,xxi4 ,,electric ,,clocks ,,and ,,batteries4 ,electric clocks may be divided into three kinds1 or principal divisions4 ,of the first-class are those in which the pendulum is driven directly from the armature by electric impulse1 or by means of a weight dropping on an arm projecting from the pendulum4 ,in this case the entire train of the clock consists of a ratchet wheel and the dial work4 ,the second class comprises the regular train from the center to the arbor4 ,this class has a spring on the center arbor1 wound more or less frequently by electricity4 ,in this case the aim is to keep the spring constantly wound1 so that the tension is almost as evenly divided as with the ordinary weight clock1 such as is used in jewelers' regulators4 ,the third system uses a weight on the end of a lever connected with a ratchet wheel on the center arbor and does away with springs4 ,one type of each of these clocks will be described so that jewelers may comprehend the principles on which the three types are built4 ,illustration3 ,fig4 #abc4 ,gillette ,clock 7,pendulum ,driven74 ,in the ,gillette ,electro-,automatic1 which belongs to the class first mentioned1 the ordinary clock principle is reversed4 ,instead of the works driving the pendulum1 the pendulum drives the train1 through the medium of a pawl and ratchet mechanism on the center arbor4 ,the pendulum is kept swinging by means of an impulse given every beat by an electromagnet4 ,this impulse is caused by the weight of the armature as it falls away from the magnet ends1 the current being used solely to pull back and re-set the armature for the next impulse4 ,any variation in the current1 therefore1 does not affect the regulation of the clock1 as the power is obtained from gravity only1 by means of the falling weight4 ,referring to the drawings1 ,figs4 #abc and #abd1 it is seen that each time the pendulum swings the train is pushed one tooth forward4 ,a cam is carried by the ratchet 7center7 arbor in which a slot is provided at a position equivalent to every fifth tooth of the ratchet4 ,into this slot drops the end of a lever1 releasing at its other end the armature prop4 ,thus at the next beat of the pendulum the armature is released and in its downward swing impulses the pendulum1 giving it sufficient momentum to carry it over the succeeding five swings4 ,the action of the life-giving armature is entirely disconnected and independent of the clock mechanism4 ,it acts on its own accord when released every tenth beat and automatically gives its impulse and re-sets itself4 ,it is provided with a double-acting contact spring 7see ,fig4 #abe7 which 8flips0 a contact leaf from one adjustable contact screw to the other as the action of the armature causes the spring to pass over its dead center4 ,thus1 when the armature reaches the lowest point in its drop 7,figs4 #abf and #abg7 the leaf snaps against the right contact screw1 the circuit is completed1 the magnet energized and the armature drawn up4 ,as the armature rises above a certain point1 the dead center of the flipper spring is again crossed and the leaf snaps back against the post at the left4 ,in the meantime1 however1 the armature prop has slipped under the end of the armature and retains it until the time comes for the next impulse4 ,illustration3 ,fig4 #abd4 ,side ,view4 ,in adjusting the mechanism of this type of clock the increasing pendulum swing should catch and push the ratchet before the buffer strikes and lifts the armature from the prop4 ,the adjustment of the 8flipper0 contact screws 7with _/ inch play7 should be such that as the armature falls the contact leaf will be thrown and the armature drawn up at a point just beyond the half way position in the swing of the pendulum4 ,the power of the impulse can be regulated by turning the adjusting post with pliers1 thus varying the tension of the armature spring1 the pull of which reinforces the weight of the armature4 ,care should be taken1 however1 that the tension is not beyond the 8quick action0 power of the electromagnet4 ,it is much better to ease up the movement in other ways before putting too great a load on the life of the battery4 ,the electrical contacts on the leaf and screw are platinum tipped to prevent burning by the electric sparking at the 8make0 and 8break40 ,this sparking is also much reduced by means of a resistance coil placed in series connection with the magnet coil1 ,fig4 #abg1 to reduce the amount of current used4 ,if this coil is removed or disconnected the constant sparking and heat would soon burn out the contact tips4 ,care should be taken to see that the batteries are dated and the battery connections are clean at the time of sliding in a new battery4 ,the brush which makes connection with the center or carbon post of the battery is insulated with mica from the framework of the case4 ,the other connection is made from the contact of the uncovered zinc case of the battery with the metal clock case surrounding it4 ,the contact points should be bright and smooth to insure good contacts4 ,these clocks need but little cleaning of the works as no oil whatever is used1 except at one place1 viz41 the armature pivot4 ,oil should never be used on the train bearings1 or other parts4 ,this clock ran successfully on the elevated railway platforms of the loop in ,chicago where no other pendulum clock could be operated on account of the constant shaking4 ,in considering the electrical systems of these clocks1 let us commence with the batteries4 ,while undoubtedly great improvements have been made in the present form of dry battery they are still very far from giving entire satisfaction4 ,practically all of them are of one kind1 which is that which produces electricity at #a volts from zinc1 carbon and sal-ammoniac1 with a depolarizer added to the elements to absorb the hydrogen4 ,the chemical action of such a battery is as follows3 ,illustration3 ,fig4 #abe4 ,the water in the electrolite comes in contact with the zinc and is decomposed thereby1 the oxygen being taken from the water by the zinc1 forming oxide of zinc and leaving the hydrogen in the form of minute bubbles attached to the zinc4 ,as this1 if allowed to stand1 would shut off the water from reaching the zinc1 chemical action would therefore soon cease and when this happens the battery is said to be polarized and no current can be had from it4 ,illustration3 ,fig4 #abf4 ,the ,electric ,contact4 ,fig4 #abg4 ,the ,wiring ,system4 ,in order to take care of the hydrogen and thus insure the constant action of the battery1 oxide of manganese is added to the contents of the cell1 generally as a mixture with the carbon element4 ,manganese has the property of absorbing oxygen very rapidly and of giving it off quite easily4 ,therefore while the hydrogen is being formed on the zinc1 it becomes an easy matter for it to leave the zinc and take its proper quantity of oxygen from the manganese and again form water1 which is again decomposed by the zinc4 ,as long as this cycle of chemical action takes place the battery will continue to give good satisfaction1 and usually when a battery gives out it is because the depolarizer is exhausted1 for the reason that the carbon is not affected at all and the zinc element forming the container is present in sufficient quantity to outlast the chemical action of the total mass4 ,there are great differences in the various makes of batteries2 also in the methods of their construction4 ,it would seem to be an easy matter for a chemist to figure out exactly how much depolarizer would serve the purpose for a given quantity of zinc and carbon and therefore to make a battery which should give an exact performance that could be anticipated4 ,in reality1 however1 this is not the case1 owing to the various conditions4 ,there are three qualities of manganese in the market2 the ,japanese1 which is the best and most costly2 the ,german1 which comes second1 and the ,american1 which is the cheapest and varies in quality so much as to be more or less a matter of guesswork4 ,we must remember that in making batteries for the price at which they are now sold on the market we are obliged to take materials in commercial quantities and commercial qualities and cannot depend upon the chemically pure materials with which the chemists' theories are always formulated4 ,this therefore introduces several elements of uncertainty4 ,in practice the ,japanese manganese will stand up for a far longer time than any other that is known and it is used in all special batteries where quality and length of life are considered of more importance than the price4 ,the ,german manganese comes next4 ,then comes a mixture of ,american and ,german manganese1 and finally the ,american manganese1 which is used in making the cheaper batteries which are sorted afterwards1 as we shall explain farther on4 ,these batteries are sealed after having been made in large quantities1 say five thousand or ten thousand in the lot1 and kept for thirty days1 after which they are tested4 ,the batteries which are likely to give short-life will show a local action and consequent reduction of output in thirty days4 ,they are1 therefore1 sorted out1 much as eggs are candled on being received in a storage warehouse1 for the reason that after a cell has been made and put together it would cost more to find out what was the matter with it and remedy that than it would to make a new cell4 ,many of the battery manufacturers1 therefore1 make up their batteries with an attempt to reach the highest standard4 ,they are sorted for grade in thirty days and those which have attained the point desired are labeled as the factories' best battery and are sold at the highest prices4 ,the others have been graded down exclusively and labeled differently until those which are positively known to be short-lived are run out and disposed of as the factories' cheapest product under still another label4 ,when buying batteries always look to see that the tops are not cracked1 as if the seal on the cell is broken1 chemical action induced from contact with the air as the battery dries out1 will rapidly deteriorate the depolarizer and sulphate the zinc1 both of which are of course a constant draft on the life of the battery1 which contains only a stated quantity of energy in the beginning4 ,always examine the terminal connections to see that they are tight and solid4 ,batteries when made up are always dated by the factory1 but this does the purchaser little good1 as the dates are in codes of letters1 figures1 or letters and figures1 and are constantly changed so that even the dealers who are handling thousands of them are unable to read the code4 ,this is done because many people are prone to blame the battery for other defects in the electrical system and many who are using great quantities would find an incentive to switch the covers on which the dates appear if they knew what it meant4 ,this is perhaps rather harsh language1 but a good many men would be tempted to send back a barrel of old batteries every now and then with the covers showing that they had not lasted three months1 if they could read these signatures4 ,practically the only means the jeweler has of obtaining a good cell1 with long life1 is to buy them of a large electrical supply house1 paying a good price for them and making sure that that house has trade enough in that battery to insure their being continuously supplied with fresh stock4 ,the position of the battery also has to do with the length of life or amount of its output4 ,thus a battery lying on its side will not give more than seventy-five per cent of the output of a battery which is standing with the zinc and carbon elements perpendicular4 ,square batteries will not give the satisfaction that the round cell does4 ,it has been found in practice by trials of numerous shapes and proportions that the ordinary size of #b #f inches will give better satisfaction than one of a different shape--wider or shorter1 or longer and thinner2 that is for the amount of material which it contains4 ,the battery which has proved most successful in gas engine ignition work is #c #h inches4 ,that maintains the same proportions as above1 or very nearly so1 but owing to local action it will give on clock work only about fifty per cent longer life than the smaller size4 ,it has been a more or less common experience with purchasers of electric clocks to find that the batteries which came with the clock from the factory ran for two or three years 7three years not being at all uncommon7 and that they were then unable to obtain batteries which would stand up to the work for more than three weeks1 up to six months4 ,the difference is in the quality and freshness of the battery bought1 as outlined above4 ,illustration3 ,fig4 #abh4 ,fig4 #abi4 ,in considering the rest of the electrical circuit1 we find three methods of wiring commonly used and also a fourth which is just now coming into use4 ,the majority of electric clocks are wound by a magnet which varies in size from three to six ohms2 bridged around the contact points1 there has generally been placed a resistance spool which varies in size from ten to twenty-five times the number of ohms in the armature magnets4 ,see ,fig4 #abh4 ,this practically makes a closed circuit on which we are using a battery designed for open circuit work4 ,if we use an electromagnet with a very soft iron core1 we will need a small amount of current1 but every time we break the contact1 we will have a very high counter electro-motive force1 leaping the air gap made while breaking the contact and therefore burning the contact points4 ,if our magnet is constructed so as to use the least current1 by very careful winding and very soft iron cores1 this counter electro-motive force will be at its greatest while the draft on the battery is at its smallest4 ,if the magnet cores are made of harder iron1 the counter electro-motive force will be much less2 but on the other hand much more current will be needed to do a given quantity of work with a magnet of the second description2 and the consequence is that while we save our contact points to some extent1 we deplete the battery more rapidly4 ,if we put in the highest possible resistance--that of air--in making and breaking our contacts1 we use current from the battery only to do useful work2 but we also have the spark from the counter electro-motive force in a form which will destroy our contact points more quickly4 ,if we reduce the resistance by inserting a ,german silver wire coil of say sixty ohms on a six-ohm magnet circuit1 we have then with two dry batteries 7the usual number7 three volts of current in a six-ohm magnet during work and three volts of current in a sixty-six ohm circuit while the contacts are broken1 ,fig4 #abh4 ,dividing the volts by the ohms1 we find that one twenty-second of an ampere is constantly flowing through such a circuit4 ,we are therefore using a dry battery 7an open circuit battery7 on closed circuit work and we are drawing from the life of our battery constantly in order to save our contact points4 ,it then becomes a question which we are going to sacrifice1 or what sort of a compromise may be made to obtain the necessary work from the magnet and at the same time get the longest life of the contact points and the batteries4 ,most of the earlier electric clocks manufactured have finally arranged such a circuit as has been described above4 ,the ,germans put in a second contact between the battery and the resistance with a little larger angular motion than the first or principal contact1 so that the contact is then first made between the battery and resistance spool1 ,b1 ,fig4 #abi1 then between the two contact points of the shunt1 ,a2 ,fig4 #abi1 to the electromagnet1 and after the work is done they are broken in the reverse order1 so that the resistance is made first and broken after the principal contact4 ,this involves just twice as many contact points and it also involves more or less burning of the second contact4 ,illustration3 ,fig4 #acj4 ,fig4 #aca4 ,the ,american manufacturers seem to prefer to waste more or less current rather than to introduce additional contact points1 as they find that these become corroded in time with even the best arrangements and they desire as few of them as possible in their movements1 preferring rather to stand the draft on the battery4 ,one ,american manufacturer inserts a resistance spool of #fj ohms in parallel with a magnet of seven ohms 7#c ohms for each magnet spool7 as in ,fig4 #acj4 ,he states that the counter electro-motive force is thus dissipated in the resistance when the contact is broken1 as the resistance thus becomes a sort of condenser1 and almost entirely does away with heating and burning of the contacts1 while keeping the circuit open when the battery is doing no work4 ,it has been suggested to the writer by several engineers of high attainments and large experience that what should be used in the above combination is a condenser in place of a resistance spool1 as there would then be no expenditure of current except for work4 ,one of the clocks changed to this system just before the failure of its manufacturers1 but as less than four hundred clocks were made with the condensers 7,fig4 #aca71 the point was not conclusively demonstrated4 ,it should also be borne in mind that the condenser has been vastly improved within the last twelve months4 ,with the condenser it will be observed that there is an absolutely open circuit while the armature is doing no work and that therefore the battery should last that much longer1 ,figs4 #acj and #aca4 ,as to the cost of the condensers as compared with resistance spools1 we are not informed1 but imagine that with the batteries lasting so much longer and the clock consequently giving so much better satisfaction1 a slight additional cost in manufacture by changing from resistance to condensers would be welcomed1 if it added to the length of life and the surety of operation4 ,electric clocks cost more to make than spring or weight clocks and sell for a higher price and a few cents additional per movement would be a very small premium to pay for an increase in efficiency4 ,the repairer who takes down and reassembles one of these clocks very often ignorantly makes a lot of trouble for himself4 ,many of the older clocks were built in such a way that the magnets could be shifted for adjustment1 instead of being put in with steady pins to hold them accurately in place4 ,the retail jeweler who repairs one of these clocks is apt to get them out of position in assembling4 ,the armature should come down squarely to the magnets1 but should not be allowed to touch1 as if the iron of the armature touches the poles of the magnet it will freeze and retain its magnetism after the current is broken4 ,some manufacturers avoid this by plating their armatures with copper or brass and this has puzzled many retailers who found an electromagnet apparently attracting a piece of metal which is generally understood to be non-magnetic4 ,the method offers a good and permanent means of insulating the iron of the armature from the magnet poles while allowing their close contact and as the strength of a magnet increases in proportion to the square of the distance between the poles and the armature1 it will be seen that allowing the armature to thus approach as closely as possible to the poles greatly increases the pull of the magnet at its final point4 ,if when setting them up the magnet and armature do not approach each other squarely1 the armature will touch the poles on one side or another and soon wear through the copper or brass plating designed to maintain their separation and then we will have freezing with its accompanying troubles4 ,a very good test to determine this is to place a piece of watch paper1 cigarette paper or other thin tissue on the poles of the magnet before the naked iron armature is drawn down4 ,then make the connection1 hold the armature and see if the paper can be withdrawn4 ,if it cannot the armature and poles are touching and means should be taken to separate them4 ,this is sometimes done by driving a piece of brass into a hole drilled in the center of the pole of the magnet2 or by soldering a thin foil of brass on the armature4 ,as long as the separation is steadily maintained the object sought is accomplished1 no matter what means is used to attain it4 ,another point with clocks which have their armatures moved in a circular direction is to see that the magnet is so placed as to give the least possible freedom between the armatures and the circular poles of the magnet1 but that there must be an air-gap between the armature and magnet poles4 ,in those clocks which wind a spring by means of a lever and ratchet working into a fine-toothed ratchet wheel1 or are driven by a weighted lever1 there is an additional point to guard against4 ,if the weight lever is thrown too far up1 either one of two things will happen4 ,the weight lever may be thrown up to ninety degrees and become balanced if the butting post is left off or wrongly replaced2 the power will then be taken off the clock1 if it is driven directly by weight1 so that a butting post should meet the lever at the highest point and insure that it will not go beyond this and thus lose the efficiency of the weight4 ,in the cases where a spring on the center arbor is interposed between the arbor and the ratchet wheel1 it should be determined just how many teeth are necessary to be operated when winding1 as if a clock is wound once an hour and the aim is to wind a complete turn 7which is the amount the arbor has run down7 if the lever is allowed to vibrate one or two teeth beyond a complete turn1 it will readily be seen that in the course of time the spring will wind itself so tightly as to break or become set4 ,this was a frequent fault with the ,dulaney clock and has not been guarded against sufficiently in some others which use the fine ratchet tooth for winding4 ,when such a clock is found the proper number of teeth should be ascertained and the rest of the mechanism adjusted to see that just that number of teeth will be wound4 ,if less is wound there will come a time when the spring will run down and the clock will stop4 ,if too much is wound the spring will eventually become set and the clock will stop4 ,therefore such movements should be examined to see that the proper amount of winding occurs at each operation4 ,of course where a spring is wound and there are but four notches in the ratchet wheel and the screw stop is accurately placed to stop the action of the armature1 over action will not harm the spring1 provided it will not go to another quarter1 as if the armature carries the ratchet wheel further than it should1 the smooth circumference between the notches will let it drop back to its proper notch4 ,there are a large number of clocks on the market which wind once per hour4 ,these differ from the others in that they do not depend upon a single movement of the armature for an instantaneous winding4 ,thus if the batteries are weak it may take twenty seconds to wind4 ,if the batteries are strong and new it may wind in six seconds4 ,in this respect the clock differs radically from the others1 and while we have not personally had them under test1 we are informed that on account of winding once per hour the batteries will last very much longer than would be expected proportionately from those which wind at periods of greater frequency4 ,the reason assigned is that the longer period allows the battery to dispose of its hydrogen on the zinc and thus to regain its energy much more completely between the successive discharges and hence can give a more effective quantity of current for hourly discharge than those which are discharged several times a minute1 or even several times an hour4 ,it is only proper to add that the manufacturers of clocks winding every six or seven minutes dispute this assertion4 ,another point is undoubtedly in the increased length of life of the contacts2 but speaking generally the electric clock may be said now to be waiting for further improvements in the batteries4 ,those who have had the greatest experience with batteries1 as the telephone companies1 telegraph companies and other public service corporations1 have generally discarded their use in favor of storage batteries and dynamos wherever possible and where this is not possible they have inspected them continuously and regularly4 ,in this respect one point will be found of great service4 ,when putting in a new set of batteries in any electrical piece of machinery1 write the date in pencil on the battery cover1 so that you1 or those who come after you1 some time later1 will know the exact length of time the battery has been in service4 ,this is frequently of importance1 as it will determine very largely whether the battery is playing out too soon1 or whether faults are being charged to the battery which are really due to other portions of the apparatus4 ,never put together any piece of electrical apparatus without seeing that all parts are solidly in position and are clean2 always look carefully to connections and see that the insulation is perfect so that short circuits will be impossible4 ,all contacts must be kept smooth and bright and contact must be made and broken without any wavering or uncertainty4 ,fig4 #acb shows the completely wired movement of the ,american ,clock ,company's weight driven movement1 which may be accepted as a type of this class of movements--weight driven1 winding every seven minutes4 ,the train is a straight-line time train1 from the center arbor to the dead beat escapement1 with the webs of the wheels not crossed out4 ,it is wired with the wire from the battery zinc screwed to the front plate ,h and that from the battery carbon to an insulated block ,g4 ,fig4 #acc shows an enlarged view of the center arbor4 ,upon this arbor are secured 7friction-tight7 two seven-notched steel ratchets1 ,e1 and carried loosely between them are two weighted levers pivoted loosely on the center arbor4 ,each lever is provided with a pawl engaging in the notches of the nearest ratchet1 as shown4 ,the weighted lever has a circular slot cut in it1 concentric with the center hole and also has a portion of its circumference at the arbor cut away1 thus forming a cam4 ,between these two levers is a connecting link ,d with a pin in its upper end1 which pin projects into the circular slots of the weight levers4 ,illustration3 ,fig4 #acb4 ,illustration3 ,fig4 #acc4 ,the lever ,f is pivoted to the front plate of the clock and carries at right angles a beveled arm which projects over the ratchets ,e1 but is ordinarily prevented from dropping into the notches by riding on the circumferences of the weighted levers4 ,when one lever has dropped down and the other has reached a horizontal position the cut portions of the circumferences of these levers will be opposite the upper notch of the ratchets and will allow the bar projecting from ,f to drop into the notches4 ,this allows ,f and ,g to connect and the magnet ,a is energized1 pulls the armature ,b1 the arms ,c ,d1 and thus lifts the lever through the pin in ,d pulling at the end of the circular slot4 ,as the lever flies upward1 the cam-shaped portion of its circumference raises the arm out of the notches1 thus separating ,f and ,g and breaking the circuit4 ,a spring placed above ,e keeps its arms pressed constantly upon ,e in position to drop4 ,the wiring of the magnets is shown in ,fig4 #acj4 ,illustration3 ,fig4 #acd4 ,the upper contact 7carried in ,f7 is a piece of platinum with its lower edge cut at an angle of fifteen degrees and beveled to a knife edge4 ,the lower point of this bevel comes into contact first and is the last to separate when breaking connection1 so that any sparking which may take place will be confined to one edge of the contacts while the rest of the surface remains clean4 7,see ,fig4 #acd47 ,ordinarily there is very little corrosion from burning and this is constantly rubbed off by the sliding of the surfaces upon each other4 ,the lower contact1 ,g1 consists of a brass block mounted upon an insulating plate of hard rubber4 ,the block is in two pieces1 screwed together1 and each piece carries a platinum tipped steel spring4 ,these springs are so set as to press their platinum tips against each other directly beneath the upper contact4 ,the upper and lower platinum tips engage each other about one-sixteenth inch at the time of making contact4 ,the lower block being in two pieces1 the springs may be taken apart for cleaning1 or to adjust their tension4 ,the latter should be slight and should in no case exceed that which is exerted by the spring in ,f1 or the upper knife edge will not be forced between the two lower springs4 ,the pin on which ,f is pivoted and that bearing on the spring above it must be clean and bright and never be oiled1 as it is through these that the current passes to the upper contact in the end of ,f4 ,the contacts are1 of course1 never oiled4 ,the two weighted levers should be perfectly free on the center arbor and their supporting pawls should be perfectly free on the shoulder screws in the levers4 ,their springs should be strong enough to secure quick action of the pawls4 ,this freedom and speed of action are important1 as the levers are thrown upward very quickly and may rebound from the butting post without engaging the ratchets if the pawls do not work quickly4 ,the projecting arm1 ,c1 of the armature1 ,b1 has pivoted to it1 a link1 ,d1 which projects upward and supports at its upper end a cross pin4 ,the link should not be tight in the slot of ,c1 but should fit closely on the sides1 in order to keep the cross pin at the top of ,d parallel with the center staff of the clock4 ,this cross pin projects through ,d an equal distance on either side1 each end respectively passing through the slot of the corresponding lever1 the total length of this pin being nearly equal to the distance between the ratchets4 ,when the electric circuit is closed1 and the magnets energized1 ,b1 ,c and ,d are drawn downward2 the weighted end of one of the levers which runs the clock1 being at this time at the limit of its downward movement1 see ,fig4 #ace1 the opposite or slotted end of said lever1 is then at its highest point1 and the downward pull in the slot by one end of the above described crosspin which enters it will throw the weighted end of the said lever upward4 ,the direct action of the magnets raises the lever nearly to the horizontal position1 and the momentum acquired carries it the remainder of the distance4 ,by this arrangement of stopping the downward pull of the pin when the ascending lever reaches the horizontal1 all danger of disturbing the other lever ,a is avoided4 ,the position is such that the top of the ascending lever weight is about even with the center of the other weight when the direct pull ceases4 ,illustration3 ,fig4 #ace4 ,before starting the clock raise the lever weights so that one lever is acting upon a higher notch of the ratchet than the other4 ,they are designed to remain about forty-five degrees apart1 so as to raise only one lever at each action of the magnet4 ,this maintains an equal weight on the train1 which would not be the case if they were allowed to rise and fall together2 keeping the levers separated also reduces the amount of lift or pull on the battery and uses less current1 which is an item when the battery is nearly run down4 ,if these levers are found together it indicates that the battery is weak1 the contacts dirty1 making irregular winding1 or the pawls are working improperly4 ,see that the levers rise promptly and with sufficient force4 ,after one of them has risen stop the pendulum and see that the butting post is correctly placed1 so that there is no danger of the lever wedging under the post and sticking there1 or causing the lever to rebound too much4 ,the butting post is set right when the clock leaves the factory and seldom needs adjustment unless some one has tinkered with it4 ,the time train should be oiled as with the ordinary movements1 also the pawls on the levers4 ,the lever bushings should be cleaned before oiling and then well oiled in order to avoid friction on the center arbor from the downward pull of the magnets when raising the levers4 ,in order to clean the levers drive out the taper pin in the center arbor and remove the front ratchet1 when the levers will slip off4 ,in putting them back care should be used to see that the notches of the ratchets are opposite each other4 ,oil the edges of the ratchets and the armature pins4 ,do not under any circumstances oil the contact points1 the pins or springs of the bar ,f1 as this will destroy the path of the current and thus stop the clock4 ,these pins must be kept clean and bright4 ,,hourly ,,winding ,,clocks4--,there are probably more of these in ,america than of all other electric kinds put together 7we believe the present figures are something like #ace1jjj71 so that it will not be unreasonable to give considerable space to this variety of clocks4 ,practically all of them are made by the ,self ,winding ,clock ,company and are connected with the ,western ,union wires1 being wound by independent batteries in or near the clock cases4 ,three patterns of these clocks have been made and we will describe all three4 ,as they are all practically in the same system1 it will probably be better to first make a simple statement of the wiring1 which is rigidly adhered to by the clock company in putting out these goods4 ,all wires running from the battery to the winding magnets of the movement are brown4 ,all wires running from the synchronizing magnet to the synchronizing line are blue4 ,master clocks and sub-master clocks have white wires for receiving the ,washington signal and the relay for closing the synchronizing line will1 have wires of blue and white plaid4 ,illustration3 ,fig4 #acf4 ,by remembering this system it is comparatively easy for a man to know what he is doing with the wires1 either inside or outside of the case4 ,for calendar clocks there are1 in addition1 two white wires running from the calendar to the extra cell of battery4 ,there is also one other peculiarity1 in that these clocks are arranged to be wound by hand whenever run down 7or when starting up7 by closing a switch key1 shown in ,fig4 #acf1 screwed to the inside of the case4 ,this is practically an open switch1 held open by the spring in the brass plate1 except when it is pressed down to the lower button4 ,the earliest movement of which any considerable number were sent out was that of the rotary winding from a three-pole motor1 as shown in ,fig4 #acg4 ,each of these magnet spools is of two ohms1 with twelve ohms resistance1 placed in parallel with the winding of each set of magnet spools1 thus making a total of nine spools for the three-pole motor4 ,illustration3 ,fig4 #acg4 ,on the front end of the armature drum arbor is a commutator having six points1 corresponding to the six armatures in the drum4 ,there are three magnets marked ,o1 ,p and ,x2 each magnet has its own brush marked ,o1 ,p and ,x4 ,when an armature approaches a magnet 7see ,fig4 #acg7 the brush makes contact with a point of the commutator1 and remains in contact until the magnet has done its work and the next magnet has come into action4 ,when properly adjusted the brush ,o will make contact when armatures #a and #b are in the position shown1 with ,no4 #b a little nearer the core of the magnet than ,no4 #a2 and it will break contact when the armature has advanced into the position shown by armature ,no4 #c1 the front edge of the armature being about one-sixteenth of an inch from the corner of the core1 armature ,no4 #d being entirely out of circuit1 as brush ,x is not touching the commutator4 ,the back stop spring1 ,s1 ,fig4 #acg1 must be adjusted so that the brush ,o is in full contact with a point of the commutator when the motor is at rest1 with a tooth of the ratchet touching the end of the spring1 ,s4 ,sometimes the back stop spring1 ,s1 becomes broken or bent4 ,when this occurs it is usually from overwinding4 ,it must be repaired by a new spring1 or by straightening the old one by burnishing with a screwdriver4 ,set the spring so that it will catch about half way down the last tooth4 ,having explained the action of the motor we come now to the means of temporarily closing the circuit and keeping it closed until such time as the spring is wound a sufficient amount to run the clock for one hour2 as the spring is on the center arbor this requires one complete turn4 ,this is the distinguishing feature of this system of clocks and is not possessed by any of the others4 ,it varies in construction in the various movements1 but in all its forms it maintains the essential properties of holding the current on to the circuit until such time as the spring has been wound a sufficient quantity1 when it is again forcibly broken by the action of the clock4 ,this is termed the 8knock away10 and exists in all of these movements4 ,to start the motor the circuit is closed by a platinum tipped arm1 ,a1 ,fig4 #ach1 loosely mounted on the center arbor1 and carried around by a pin projecting from the center wheel until the arm is upright1 when it makes contact with the insulated platinum tipped brush1 ,b4 ,a carries in its front an ivory piece which projects a trifle above the platinum top1 so that when ,b drops off the ivory it will make contact with the platinum on ,a firmly and suddenly4 ,this contact then remains closed until the spring barrel is turned a full revolution1 when a pin in the barrel cover brings up the 8knock-away10 ,c1 which moves the arm1 ,a1 forward from under the brush1 ,b1 and breaks the circuit4 ,the brush1 ,b1 should lie firmly on its banking piece1 and should be so adjusted that when it leaves the arm1 ,a1 it will drop about one-thirty-second of an inch4 ,adjusted in this way it insures a good1 firm contact4 ,the angle at the top of the brush1 ,b1 must not be too abrupt1 so as to retard the action of the clock while the contact is being made4 ,wire ,no4 #h connects the spring contact1 ,b1 to one of the binding plates at the left hand side of the case2 and wire ,no4 #f connects the motor1 ,m1 to the other4 ,to these binding plates are attached brown wires that lead one to each end of the battery4 ,when the clock is quite run down1 it is wound by pressing the switch key1 ,fig4 #acf1 from which a wire runs to the plate4 ,the switch key should not be permanently connected to its contact screw1 ,j4 ,see that all wires are in good condition and all connections tight and bright4 ,the main spring is wound by a pinion on the armature drum arbor1 through an intermediate wheel and pinion to the wheel on the spring barrel4 ,at stated times--say once in eighteen months or two years--all clocks should be thoroughly cleaned and oiled1 and at the same time inspected to be sure they are in good order4 ,never let the self-winding clocks run down backward1 as the arm1 ,a1 ,fig4 #ach1 will be carried back against the brush1 ,b1 and bend it out of adjustment4 ,illustration3 ,fig4 #ach4 ,to clean the movement1 take it from the case1 take out the anchor and allow it to run down gently1 so as not to break the pins1 then remove the motor4 ,take off the front plate and separate all the parts4 ,never take off the back plate in these clocks4 ,wash the plates and all parts in a good quality of benzine1 pegging out the holes and letting them dry thoroughly before reassembling4 ,the motor must not be taken apart1 but may be washed in benzine1 by using a small brush freely about the bearings1 commutator and brushes4 ,put oil in all the pivot holes1 but not so much that it will run4 ,the motor bearings and the pallets of the anchor should also be oiled4 ,inspect carefully to see that the center winding contact is right and that the motor is without any dead points4 ,dust out the case and put the movement in place4 ,before putting on the dial try the winding by means of the switch1 ,fig4 #acf1 to be sure that it is right2 also see that the disc on the cannon socket is in the right position to open the latch at the hour1 and after the dial and hands are on move the minute hand forward past the hour and then backward gently until it is stopped by the latch4 ,this will prove that the hand is on the square correctly4 ,on account of the liability of the motor to get out of adjustment and fail to wind1 from the shifting of the springs and brushes1 under careless adjustment1 various attempts have been made to improve this feature of these clocks and the company is now putting out nearly altogether one of the two vibrating motors1 shown in ,figs4 #aci and #adj4 ,in ,style ,c1 ,fig4 #aci1 the hourly contact for winding is the same as in the clock with the three-magnet motor1 as shown in ,fig4 #ach4 ,the magnet spools are twelve ohms and the resistance coil is eighty ohms1 placed in parallel1 as described in ,fig4 #acj4 ,the vibrating motor1 ,fig4 #aci1 is made with a pair of magnets and a vibrating armature4 ,the main spring is wound by the forward and backward motion of the armature1 one end of the connecting rod1 #h1 being attached to a lug of the armature1 #b1 and the other to the winding lever1 #aj4 ,this lever has spring ends1 to avoid shock and noise4 ,as the winding lever is moved up and down1 the pawl1 #i1 turns the ratch wheel1 #aa1 and a pinion on the ratch wheel arbor turns the spring barrel until the winding is completed4 ,illustration3 ,fig4 #aci4 ,the contact for operating the motor is made by the brass spiral spring1 #c1 which is attached to the insulated stud1 #d1 and the platinum pin1 #e1 which is carried on a spring attached to the clock plate4 ,as the armature moves forward the break pin1 ,a1 in the end of the armature lifts the contact spring1 #c1 thus breaking the circuit4 ,the acquired momentum carries the armature forward until it strikes the upper banking spring1 #f1 when it returns rapidly to its original position1 banking on spring #g1 by which time contact is again made between springs #c and #e and the vibration is repeated until the clock is wound one turn of the barrel and the circuit is broken at the center winding contact4 ,fig4 #adj1 ,style ,f1 is a similar motor so far as the vibrating armature and the winding is concerned1 but the winding lever is pivoted directly on the arbor of the winding wheel and operates vertically from an arm and stud on the armature shaft1 working in a fork of the winding lever1 #h1 ,fig4 #adj4 ,it will be seen that the train and the motor winding mechanism are combined in one set of plates4 ,the motor is of the oscillating type and its construction is such that all its parts may be removed without dissembling the clock train4 ,,construction ,,of ,,the ,,motor4--,the construction of the motor is very simple1 having only one pair of magnets1 but two sets of make and break contacts1 one set of which is placed on the front and the other on the back plate of the movement1 thus ensuring a more reliable operation of the motor1 and reducing by fifty per cent the possibility of its failing to wind4 ,the center winding contact also differs from those used in the three-magnet motors and former styles of vibrating motor movements4 ,the center winding contact piece1 #ac1 has no ivory and no platinum4 ,the hourly circuit is not closed by the current passing through this piece1 but it acts by bringing the plate contact spring1 #af1 in metallic connection with the insulated center winding contact spring1 #ag1 both of which are platinum tipped4 ,it will thus be seen that no accumulation of dirt1 oil or gum around the center arbor or the train pivots will have any effect in preventing the current from passing from the motor to the hourly circuit closer4 ,illustration3 ,fig4 #adj4 ,the operation is as follows3 ,as the train revolves1 the pin1 #ab1 securely fastened to the center arbor1 in its hourly revolution engages a pin on the center winding contact piece1 #ac4 ,this piece as it revolves pushes the plate contact spring1 #af1 upward1 bringing it in metallic connection with the center winding contact spring1 #ag1 which is fastened to a stud on an insulated binding post1 #ah1 thereby1 closing the hourly circuit4 ,the current passes from the binding post1 #ah1 through the battery 7or any other source of current supply7 to binding post #ai1 to which is connected one end of the motor magnet wire4 ,the current passes through these magnets to the insulated stud1 #d4 ,to this stud the spiral contact spring1 #c1 is fastened and the current passes from this spring to the plate contact spring1 #e1 thence through the movement plate to plate contact spring1 #af1 and from there through spring1 #ag1 back to the battery4 ,the main spring is wound by the forward and backward motion of the armature1 #b4 ,to this armature is connected the winding lever1 #h4 ,as the winding lever is oscillated1 the pawl1 #i1 turns the ratchet wheel1 #aa1 and a pinion on the ratchet wheel arbor turns the winding wheel until the pin1 #ae1 connected to it engages the knock-away piece1 #ad1 revolving it until it strikes the pin on the center winding contact piece1 #ac1 and pushes it from under the plate contact spring1 thereby breaking the electric circuit and completing the hourly winding4 ,the proper position of the contact springs is clearly indicated in ,fig4 #adj4 ,the spring1 #af1 should always assume the position shown thereon4 ,when the center winding contact piece1 #ac1 comes in metallic connection with the plate contact spring1 #af1 the end of this spring should stand about one-thirty-second of an inch from the edge of the incline4 ,the center winding contact spring1 #ag1 should always clear the plate contact spring one-thirty-second of an inch4 ,when the two springs touch they should be perfectly parallel to each other4 ,,adjustments ,,of ,,the ,,armature4--,in styles ,c and ,f1 when the armature1 #b1 rests on the banking spring1 #g1 its front edge should be in line with the edge of the magnet core4 ,the upper banking spring1 #f1 must be adjusted so that the front edge of the armature will be one-sixteenth of an inch from the corner of the magnet core when it touches the spring4 ,when the contact spring1 #c1 rests on the platinum pin1 #e1 it should point to about the center of the magnet core1 with the platinum pin at the middle of the platinum piece on the spring4 ,to adjust the tension of the spiral contact spring1 #c1 take hold of the point with a light pair of tweezers and pull it gently forward1 letting it drop under the pin4 ,it should take the position shown by the dotted line1 the top of the spring being about one-thirty-second of an inch below the platinum pin4 ,if from any cause it has been put out of adjustment it can be corrected by carefully bending under the tweezers1 or the nut1 #d1 may be loosened and the spring removed4 ,it may then be bent in its proper shape and replaced4 ,the hole in the brass hub to which the spring is fastened has a flat side to it1 fitting a flat on the insulated contact stud4 ,if the contact spring is bent to the right position it may be taken off and put back at any time without changing the adjustment1 or a defective spring may readily be replaced with a new one4 ,when the armature touches the upper banking spring the spiral contact spring1 #c1 should clear the platinum pin1 #e1 about one-sixteenth of an inch4 ,both contacts on front and back plates in style ,f are adjusted alike4 ,the circuit break pins 8,a0 on the armature should raise both spiral contact springs at the same instant4 ,if for any reason the motor magnets have become displaced they may readily be readjusted by loosening the four yoke screws holding them to the movement plates4 ,hold the armature against the upper banking spring1 move the magnets forward in the elongated slot1 #bj1 until the ends of the magnet cores clear the armature by one-sixty-fourth of an inch1 then tighten down the four yoke screws4 ,connect the motor to the battery and see that the armature has a steady vibration and does not touch the magnet core4 ,the adjustment should be such that the armature can swing past the magnet core one-eighth to three-sixteenths of an inch4 ,,description ,,of ,,synchronizer4--,at predetermined times a current is sent through the synchronizer magnet1 ,d1 ,fig4 #ada1 which actuates the armature1 ,e1 to which are attached the levers1 ,f and ,g1 moving them down until the points on the lever1 ,g1 engage with two projections1 #d and #e1 on the minute disc2 and lever ,f engages with the heart-shaped cam or roll on the seconds arbor sleeve1 causing both the minute and second hands to point to ,,xii4 ,these magnet spools are wound to twelve ohms1 with an eighty-ohm resistance in parallel4 ,on the latch1 ,l1 is a pin1 ,i1 arranged to drop under the hook1 ,h1 and prevent any action of the synchronizing levers1 except at the hour4 ,a pin in the disc on the cannon socket unlocks the latch about two minutes before the hour and closes it again about two minutes after the signal4 ,this is to prevent any accidental 8cross0 on the synchronizing line from disturbing the hands during the hour4 ,m is a light spring attached to the synchronizing frame to help start the armature back after the hands are set4 ,the wires from the synchronizing magnet are connected to binding plates at the right-hand side of the clock and from these binding plates the blue wires1 ,nos4 #i and #aj1 pass out at the top of the case to the synchronizing line4 ,if the clock gets out of the synchronizing range it generally indicates very careless regulation4 ,the clock is regulated by the pendulum1 as in all others1 but there is one peculiarity in that the pendulum regulating nut has a check nut4 ,if the clock gains time turn the large regulating nut under the pendulum bob slightly to the left4 ,if the clock loses time turn the nut slightly to the right4 ,loosen the small check nut under the regulating nut before turning the regulating nut1 and be sure to tighten the check nut after moving the regulating nut4 ,illustration3 ,fig4 #ada4 ,the friction of the seconds hand is very carefully adjusted at the factory1 being weighed by hanging a small standard weight on the point of the hand4 ,if it becomes too light and the hand drives or slips backward1 losing time1 it can be made stronger by laying it on a piece of wood and rubbing the inner sides of the points with a smooth screw driver1 and if too heavy and the clock will not set when the synchronizing magnets are actuated1 the points of the spring in the friction may be straightened a little4 ,if the seconds hand sleeve does not hold on the seconds socket1 pinch it a little with pliers4 ,if the seconds hand is loose on the sleeve put on a new one or solder it on the under side4 ,in style ,f the synchronizing lever1 heart-shaped seconds socket and cams on the cannon sockets are the same as in the old style movements1 shown in ,fig4 #ada4 ,the difference is in the synchronizing magnets and the way they operate the synchronizing lever4 ,the magnet has a flat ended core instead of being eccentric like the former ones4 ,the armature is also made of flat iron and is pivoted to a stud fastened to the synchronizing frame4 ,the armature is connected to the synchronizing lever by a connecting rod and pitman screws4 ,a sector has an oblong slot1 allowing the armature to be lowered or raised one-sixteenth of an inch4 ,the synchronizing lever is placed on a steel stud fastened to the front plate and held in position by a brass nut4 ,the synchronizing magnets are #ab ohms with #hj ohms resistance and are fastened to a yoke which is screwed to the synchronizing frame by four iron screws4 ,the holes in the synchronizing frame are made oblong1 allowing the yoke and magnets to be raised or lowered one-sixteenth of an inch4 ,the spring on top of the armature is used to throw it back quickly and also acts as a diamagnetic1 preventing the armature from freezing to the magnets4 ,a screw in the stud is used to screw up against the magnet head1 preventing any spring that might take place on the armature stud4 ,binding posts are screwed to the synchronizing frame and the ends of the magnet coils are fastened thereto with metal clips4 ,the blue wires in the clock case are coiled and have a metal clip soldered to them4 ,they connect direct by these clips to the binding posts1 thus making a firm connection1 and are not liable to oxidize4 ,with the various points of adjustment a pair of magnets burned out or otherwise defective may readily be replaced in from five to ten minutes4 ,when replacing a pair of synchronizing magnets proceed as follows3 ,remove the old pair and then loosen all four screws in the yoke1 pushing it up against the tops of the oblong holes1 then tighten down lightly4 ,fasten the new pair of magnets to the yoke with the inner ends of the coils showing at the outside of the movement4 ,press the armature upward until the synchronizing lever locks tightly on the cannon socket and the heart-shaped cams1 then loosen the magnet yoke screws and press the magnets down on the spring on top of the armature4 ,then tighten the yoke screws on the front plate and see that the back of the magnets clears the armature by one-hundredth of an inch 7the thickness of a watch paper71 when the screws in the back of the yoke can be set down firmly4 ,the adjustment screw may then be turned up until it presses lightly against the magnet head4 ,when current is passed through the magnets and held there the armature must clear the magnets without touching4 ,the magnet coils must then be connected to their respective binding posts by slipping the metal clips soldered to them under the rubber bushing1 making a metallic connection with the binding plates4 ,fasten these screws down tight to insure good connections4 ,illustration3 ,fig4 #adb4 ,,the ,,master ,,clock4--,is a finely finished movement with mercurial pendulum that beats seconds and a ,gerry gravity escapement4 ,at the left and near the center of the movement is a device for closing the synchronizing circuit once each hour4 ,the device consists of a stud on which is an insulator having two insulated spring fingers1 ,c and ,d1 one above the other1 as shown in ,fig4 #adb1 except at the points where they are cut away to lie side by side on an insulated support4 ,on these fingers1 and near the insulator1 are two platinum pieces1 ,e and ,f1 so adjusted as to be held apart1 except at the time of synchronizing4 ,a projection1 ,b1 from the insulator rests on the edge of a disc on the center arbor4 ,at ten seconds before the hour1 a notch in this disc allows the spring to draw the support downward1 leaving the points of the fingers1 ,c and ,d1 resting on the raised part of the rubber cam on the escape arbor4 ,the end of the finger1 ,c1 is made shorter than that of ,d1 and at the fifty-ninth second1 ,c drops and closes the circuit by ,e striking ,f4 ,at the next beat of the pendulum the long finger ,d drops and opens the circuit again4 ,the winding is the same as in the regular self-winding clocks1 the motor wire and seconds contact being connected to the binding plates at the left1 from which brown wires lead up to the battery4 ,two wires from the synchronizing device are connected to the binding plates at the left1 from which blue wires run out to the line4 ,before connecting the clock to the line it must be run until it is well regulated1 and also to learn if the contacts are working correctly4 ,regulate at first by the nut at the bottom of the rod until it runs about one second slow in #bd hours 7a full turn of the nut will change the rate about one-half minute per day74 ,the manufacturers send with each clock a set of auxiliary pendulum weights1 the largest weighing one gram1 the next in size five decigrams and the smallest two decigrams2 these weights are to make the fine regulations by placing one or more of them on the little table that is fastened about the middle of the pendulum rod4 ,the five decigram weight will make the clock gain about one second per day1 and the other weights in proportion4 ,care must be taken not to disturb the swing of the pendulum1 as a change of the arc changes the rate4 ,to start the clock after it is regulated1 stop it1 with the second hand on the fiftieth second2 move the hands forward to the hour at which the signal comes from the observatory2 then press the minute hand back gently until it is stopped by the extension on the hour contact1 ,fig4 #adb1 and beat the clock up to the hour4 ,this ensures the hour contact being in position to send the synchronizing signal4 ,a good way to start it with observatory time is with all the hands pointing to the 8signal0 hour2 hold the pendulum to one side and when the signal comes let it go4 ,with a little practice it can be started very nearly correct4 ,clocks not lettered in the bottom of the case must be wound before starting the pendulum4 ,to do this press the switch shown in ,fig4 #acf1 which is on the left side of the case and under the dial4 ,continue the pressure until the winding ceases4 ,then set the hands and start the pendulum in the usual way4 ,if the bell is not wanted to ring1 bend back the hammer4 ,,secondary ,,dials4--,one of the most deceptive branches of clock work is the secondary dial1 or 8minute jumper40 ,ten years ago it was the rule for all manufacturers of electric clocks to put out one or more patterns of secondary dials4 ,theoretically it was a perfect scheme1 as the secondary dial needed no train1 could be cheaply installed and could be operated without trouble from a master clock1 so that all dials would show exactly the same time4 ,practically1 however1 it proved a very deceptive arrangement4 ,the clocks were subject to two classes of error4 ,one was that it was extremely difficult to make any mechanical arrangement in which the hands would not drive too far or slip backward when the mechanism was released to advance the minute hand4 ,the second class of errors arose from faulty contacts at the master clock and variation in either quantity or strength of current4 ,another and probably the worst feature was that all such classes of apparatus record their own errors and thereby themselves provide the strongest evidence for condemnation of the system4 ,clocks could be wound once an hour with one-sixtieth of the chance of error of those wound once per minute1 and they could be wound hourly and synchronized daily with _/th of the line troubles of a minute system4 ,the minute jumpers could not be synchronized without costing as much to build and install as an ordinary self-winding clock1 with pendulum and time train1 and after trying them for about ten years nearly all the companies have substituted self-winding time train clocks with a synchronizing system4 ,they have apparently concluded that1 since it seems too much to expect of time apparatus that it will work perfectly under all conditions1 the next thing to do is to make the individual units run as close to time as is commercially practicable and then correct the errors of those units cheaply and quickly from a central point4 ,it is for these reasons that the secondary dial has practically disappeared from service1 although it was at one time in extensive use by such companies as the ,western ,union ,telegraph ,company1 the ,postal ,telegraph and the large buildings in which extensive clock systems have been installed4 ,fig4 #adc shows one form of secondary dial which involves a screw and a worm gear on the center arbor1 which1 it will be seen1 is adapted to be turned through one minute intervals without the center arbor ever being released from its mechanism4 ,this worm gear was described in the ,,american ,,jeweler about fifteen years ago1 when patented by the ,standard ,electric ,time ,company in connection with their motor-driven tower clocks1 and modifications of it have been used at various times by other companies4 ,the worm gear and screw system shown in ,fig4 #adc has the further advantage that it is suitable for large dials1 as the screw may be run in a box of oil for dials above four feet and for tower clocks and outside work4 ,this will readily be seen to be an important advantage in the case of large hands when they are loaded with snow and ice1 requiring more power to operate them4 ,illustration3 ,fig4 #adc4 ,minute jumper4 ,a1 armature2 ,m1 magnets2 ,w1 worm gear on center arbor2 ,b1 oil box for worm2 ,r1 four toothed ratchet4 ,all secondaries operate by means of an electromagnet raising a weight1 the weight generally forming the armature2 the fall of the weight then operates the hands by gravity4 ,direct action of the current in such cases is impracticable1 as the speed of starting with an electric current would cause the machine to tear itself to pieces4 ,this screw gear is the only combination known to us that will prevent the hands from slipping or driving by and reduces the errors of the secondary system to those of one class1 namely1 imperfections in the contact of the master clock1 insufficient quantity or strength of current1 or accidental 8crosses0 and burnings4 ,the series arrangement of wiring secondaries was formerly greatly favored by all of the manufacturers1 but it was found that if anything happened to one clock it stopped the lot of them2 and where more than fifty were in series1 the necessary voltage became so high that it was impracticable to run the clocks with minute contacts4 ,the modern system1 therefore1 is to arrange them in multiples1 very much after the fashion of incandescent lamps1 then if one clock goes wrong the others are not affected4 ,or if the current is insufficient to operate all1 only those which are farthest away would go out of time4 ,very much smaller electromagnets will do the work than are generally used for it1 and the economy of current in such cases is worth looking after1 as with sixty contacts per hour batteries rapidly play out if the current used is at all excessive4 ,where dry batteries are used on secondaries care should be taken to get those which are designed for gas engine ignition or other heavy work4 ,wet batteries1 with the zincs well amalgamated1 will give much better satisfaction as a rule and if the plant is at all large it should be operated from storage cells with an engineer to look after the battery and keep it charged1 unless current can be taken from a continuously charged lighting main4 ,this can be readily done in such instances as the specifications call for in the new custom house in ,new ,york1 namely1 one master clock and #afj secondary dials4 ,,electric ,,chimes4--,there have lately come into the market several devices for obtaining chimes which allow the separation of the chimes and the timekeeping apparatus1 connection being made by means of electricity4 ,in many respects this is a popular device4 ,it allows1 for instance1 a full set of powerful tubular chimes1 six feet or more in length1 to be placed in front of a jewelry store1 where they offer a constant advertisement1 not only of the store itself1 but of the fact that chiming clocks may be obtained there4 ,it also allows of the completion by striking of a street clock which is furnished with a time train and serves at once as timepiece and sign4 ,many of these have tubular chimes in which the hour bell is six feet in length and the others correspondingly smaller4 ,they have also been made with bells of the usual shape1 which are grouped on posts1 or hung in racks and operated electrically4 ,it may also be used as a ship's bell outfit by making a few minor changes in the controller4 ,illustration3 ,fig4 #add4 ,chimes of bells in rack4 ,illustration3 ,fig4 #ade4 ,chimes of bells with resonators4 ,fig4 #add shows a peal of bells in which the rack is thirty-six inches long and the height of the largest bell is eight inches1 and the total weight thirty pounds4 ,this1 as will readily be seen1 can be placed above a doorway or any other convenient position for operation2 or it may be enclosed in a lattice on the roof1 if the building is not over two stories in height4 ,the lattice work will protect the bells from the weather and at the same time let out the sound4 ,fig4 #ade shows the same apparatus with resonators attached4 ,these are hollow tubes which serve as sounding boards1 largely increasing the sound and giving the effect of much larger bells4 ,fig4 #adf shows a tubular chime and the electrical connections from the clock to the controller and to the hammers1 which are operated by electromagnets1 so that a heavy leaden hammer strikes a solid blow at the tops of the tubes4 ,illustration3 ,fig4 #adf4 ,tubular electric chimes4 ,the dials of such clocks contain electrical connections and the minute hand carries a brush at its outer end4 ,the contact is shown in enlarged view in ,fig4 #adg1 by which it will be seen that the metal is insulated from the dial by means of hard rubber or other insulating material1 so that the brush on the minute hand will drop suddenly and firmly from the insulator to the metallic contact when the minute hand reaches fifteen1 thirty1 forty-five or sixty minutes4 ,there is a common return wire1 either screwed to the frame of the clock1 or attached to the dial1 which serves to close the various circuits and to give four strokes of the chimes at the quarter1 eight at the half1 twelve at the three-quarter1 and sixteen at the hour1 followed by the hour strike4 ,the friction on the center arbor is of course adjusted so as to carry the minute hand without slipping at the contacts4 ,illustration3 ,fig4 #adg4 ,enlarged view of connections on dial4 ,by this means a full chime clock may be had at much less cost than if the whole apparatus had to be self-contained and the facilities of separation between the chimes and the timekeeping apparatus1 as hinted above1 gives many advantages4 ,for instance1 the same clock and controller may operate tubes inside the room and bells outside1 or vice versa4 ,these are operated by wet or dry batteries purchased at local electrical supply houses1 and the wiring is done with plain covered bell wire1 or they may be operated by current from a lighting circuit1 suitably reduced1 if the current is constantly on the mains4 ,as a full chime with sixteen notes at the hour strikes more than a thousand times a day1 considerable care should be taken to obtain only the best batteries where these are used1 as after the public gets used to the chimes the dealer will be greatly annoyed by the number of people asking for them if they are stopped temporarily4 ,there has lately developed a tendency to avoid the set tunes1 such as the ,westminster and the ,whittington chimes1 and to sound the notes as complete full notes1 such as the first1 third and fifth of the octave for the first1 second and third quarters1 followed by the hour strike4 ,this allows them to be struck in any order and for a smaller chime reduces the cost considerably4 ,the tubes used are rolled of bell metal and vary in pitch with the manufacture1 so that the only way to obtain satisfactory tones is to cut your tubes a little long and then tune them by cutting off afterwards1 the tone depending upon the thickness of the wall of the tube and its length4 ,the bells are tuned by turning from the rim or from the upper portions as it is desired to raise or lower the tone1 and if the resonators are used they are tuned in unison with the bells4 ,illustration3 ,fig4 #adh4 ,connections and contacts on front of clock dial4 ,of the ordinary bells1 ,fig4 #add1 the dimensions run3 ,first1 height four inches1 diameter #e2 second1 height four inches1 diameter #e inches2 third1 height #d inches1 diameter #e inches2 fourth1 height #d inches1 diameter #e inches2 fifth1 height #d inches1 diameter #f inches4 ,for the tubes the approximate length is six feet for the longest tube and the total weight of the chimes is #dc pounds4 ,for the controller the size is nine by eleven by six inches1 with a weight of ten pounds4 ,the hour strike may be had separately from the chimes if desired4 ,illustration3 ,fig4 #adi4 ,connections and wiring on back of clock dial4 ,this makes an easily divisible system and one that is becoming very popular with retail jewelers and to some extent with their customers4 ,,chapter ,,xxii4 ,,the ,,construction ,,and ,,repair ,,of ,,dials4 ,probably no portion of the clock is more important than the dial and it is apparently for this reason that we find so little variation in the marking4 ,the public refuses to accept anything in the way of ornamentation which interferes with legibility and about all that may be attempted is a little flat ornament in light colors which will not obscure the sight of the hands1 as it is in reality the angle made by the two hands which is read instead of the figures4 ,in proof of this may be cited the many advertising dials in which one letter takes the place of each character upon the dial and of the tower clocks in which the hours are indicated merely by blackened characters1 being nothing less than an oblong blotch on the dial4 ,thousands of people will pass such a dial without ever noticing that the regular characters do not appear4 ,various attempts have been made to change the colors and the sizes and shapes of the characters but comparatively few are successful4 ,a black dial with gold characters and hands is generally accepted1 or a cream dial with black hands1 but any further experiments are dangerous except in the cases of tower clocks1 which may have gold hands on any light colored dial1 or a glass dial4 ,in all such cases legibility is the main factor sought and the bright metal is far plainer for hands and chapters than anything that may be substituted for them4 ,in tower clocks the rule is to have one foot of diameter of the dial for every ten feet of height4 ,thus a clock situated one hundred feet above the ground level should have a ten foot dial4 ,on very large dials this rule is deviated from a little1 but not much4 ,all dials1 except those of tower clocks1 should be fastened to the movement1 rather than to the case4 ,this is particularly true where a seconds hand1 with the small opening for the seconds hand sleeve1 makes any twisting or warping of the case and consequent shifting of the dial liable to rub the dial against the sleeve at the seconds hand and thus interfere with the timekeeping4 ,the writer has in mind a case in which a large number of fine clocks were installed in a new brick and stone building4 ,they were finely finished and no sooner had they been hung on the damp walls than the cases commenced to swell and twist4 ,it was necessary three times to send a man to move the dials which had been attached to these clocks4 ,as there were about thirty clocks it will be seen that this was expensive4 ,after the walls had dried out the cases began to go back to the positions in which they were originally1 as the moisture evaporated from the cases1 and the dials had consequently to be moved through another series4 ,all told it took something like a week's work for one man to shift these dials half a dozen times during the first nine months of their installation4 ,if these dials had been fastened on pillars on the movements1 the shrinking and swelling of the cases would not have affected them4 ,it is for this reason that dials are invariably fastened on the movements of all high class clocks4 ,the characters on clock dials are still very largely ,roman1 the numerals being known as chapters4 ,attempts have been recently made to substitute ,arabic figures and in such cases the ,arabic figures remain upright throughout the series1 while the chapters invariably point the foot of the ,roman numeral toward the center of the dial4 ,this makes the ,roman numerals from ,,iiii to ,,viii upside down1 while in the ,arabic numerals this inversion does not occur4 ,the proportions generally sanctioned by usage have been found1 after measuring clock dials1 all the way from two to eighteen inches1 and may be given in the following terms3 ,with a radius of #bf mm4 the minute circle is #a mm4 ,the margin between minute circles and chapters is #a mm4 ,the chapters are #h mm4 ,the width of the thick stems of the letters are mm4 ,the width of an ,x is #d mm4 and the slanting of ,x's and ,v's is twenty degrees from a radius of the dial4 ,the letters should be proportioned as follows3 ,the breadth of an ,i and a space should equal one-half the breadth of an ,x1 that is1 if the ,x is one-half inch broad1 the ,i will be three-sixteenths inch broad and the space between letters one-sixteenth inch1 thus making the ,i plus one space equal to one-quarter inch or half the breadth of an ,x4 ,the ,v's should be the same breadth as the ,x's4 ,after the letters have been laid off in pencil1 outline them with a ruling pen and fill in with a small camel's hair brush1 using gloss black paint thinned to the proper consistency to work well in the ruling pen4 ,using the ruling pen to outline the letters gives sharp straight edges1 which would be impossible with a brush in the hands of an inexperienced person4 ,for tower clocks the chapters and minutes together will take up one-third of the radius of the dial2 the figures two-thirds of this1 or two-ninths of the radius1 and the minutes two-thirds of the remaining one-ninth of the radius1 with every fifth minute more strongly marked than the rest4 ,we often hear stories concerning the ,,iiii in place of ,,iv4 ,the story usually told is that ,louis ,,xiv of ,france was inspecting a clock made for him by a celebrated watchmaker of that day and remarked that the ,,iv was an error4 ,it should be ,,iiii4 ,there was no disputing the ,king and so the watchmaker took away the dial and had the ,,iiii engraved in place of ,,iv1 and that it has thus remained in defiance of all tradition4 ,mr4 ,a4 ,l4 ,gordon1 of the ,seth ,thomas ,clock ,co41 has the following to say concerning this story and thus furnishes the only plausible explanation we have ever seen for the continuance of this manifest error in the ,roman numeral of the dial3 8,that the attempt has been made to use the ,,iv for the fourth hour on clock dials1 any one making a study of them may observe4 ,the dials on the ,big ,ben clock in the tower of the ,parliament buildings1 ,london1 which may be said to be the most celebrated clock in the world1 have the ,,iv mark1 and the dial on the ,herald building in ,new ,york ,city also has it4 8,that the ,,iiii mark has come to stay all must admit1 and if so there must be a good and sufficient reason4 ,art writers tell us that pictures must have a balance in the placing and prominence of the several subjects4 ,most conventional forms are equally balanced about a center line or a central point4 ,of the latter class the well known trefoil is a common example4 8,a clock or watch dial with ,roman numerals has three points where the numerals are heavier1 at the ,,iiii1 ,,viii and ,,xii4 ,fortunately these heavier numerals come at points equally spaced about the center of the dial and about a center line perpendicular to the dial4 ,of these three heavy numerals the lighter of them comes at the top and it is especially necessary that the other two1 which are placed at opposite points in relation to the center line1 should be balanced as nearly as possible4 ,as the ,,viii is the heavier and cannot be changed1 the balancing figure must be made to correspond as nearly as possible1 and if marked as ,,iv1 it will not do so nearly as effectively as if the usual ,,iiii is used40 ,it is comparatively an easy matter to make a metal dial either of zinc1 copper or brass1 by laying out the dial as indicated above with ,roman chapters and numerals1 after first varnishing the metal with asphaltum4 ,this may be drawn upon with needle points which cut through the asphaltum and make a firmly defined line on the metal4 ,it is best to lay out your dial in lead pencil and then take a metal straight edge and a needle point and trace through on the pencil marks4 ,mistakes may be painted out with asphaltum1 so that the job becomes easy4 ,after this has been done a comparatively dull graver may be used to cut or scrape away the asphaltum where the metal is to be etched and then the plate may be laid in a tray1 a solution of chloride of iron poured on and rocking the tray will rapidly eat away the metal1 forming sunken lines wherever the copper or brass is not protected by the asphaltum4 ,this furnishes a rough surface on the etched portions1 which enables the filling to stick much better than if it were smooth4 ,in tracing the circles a pair of heavy1 stiff1 carpenters' compasses will serve where the watchmaker has not a lathe large enough to swing the dial4 ,in all such cases it is best to start with a prick-punched center1 tracing the minute circles and the serifs of the chapters with the compasses and then do your further division and marking by lead pencil1 followed with the needle and then by the acids4 ,it should be done before the holes are bored for the minute and seconds centers1 as you then have an exact center to mark from and can go back to it many times4 ,this will be necessary in dividing the minute or seconds circle by hand 7without an index on the lathe71 as one of the tests of true division consists in having all marks lined up with a straight edge placed across the center4 ,thus ,,ix and ,,iii should be in line with the center2 ,,vi and ,,xii2 ,x and ,,iiii2 ,i and ,,vii1 etc4 ,it will readily be seen that for such purposes of reference the center should not be punched too large4 ,if it is desirable to ornament the dial1 the desired ornament may be drawn on in the plain surface through the asphaltum and etched at the same time as the chapters and degrees4 ,or chapters and ornament may be drawn1 pierced with a saw1 engraved1 filed up and backed up with a plain plate of another color4 ,gold ornament and silver background looks well4 ,practically all the clocks having seconds hands carry that hand in such a position as to partially obscure the ,,xii1 with the exception of watchmakers' regulators1 and these1 if they have separate hour1 minute and seconds circles1 are made large enough to occupy the space between the center and the minute circle1 placing the hour circle between the center and the thirtieth minute2 the seconds between the center and the sixtieth minute4 ,the reason for this is that in the watchmakers' regulators the hours are almost a matter of indifference2 minutes are seldom referred to2 the real comparison in watch regulation comes on the seconds hand4 ,for this reason the seconds hand is made as large as possible and the chapters being placed on the hour circle by themselves1 the seconds circle may occupy almost the entire distance between the center of the dial and the minute circle4 ,they are placed one above the other because in regulators the time train is nearly always a straight-line train1 which brings the seconds arbor vertically over the center arbor1 and consequently the centers of the dials must be placed on a vertical line4 ,when the engraving has been properly done on a flat dial it is desirable to fill it with black in order to make it legible4 ,there are several methods by which this may be done4 ,the most durable is to make a black enamel and if it is a valuable clock the movement is generally worth a fine dial4 ,the following formula will furnish a good black enamel3 ,siliceous sand #ab parts ,calcined borax #bj parts ,glass of antimony #d parts ,saltpetre #a part ,chalk #b parts ,peroxide of ,manganese #e parts ,fine ,saxony ,cobalt #b parts ,the enamel is ground into coarse particles like sand1 and the incised lines filled with it1 after which the brass or copper plate is heated red hot to fuse the enamel4 ,two or three firings may be necessary to completely fill the lines2 after filling they are stoned off level with the surface of the dial4 ,jeweler's enamel may be purchased of material dealers and used for the dials4 ,black asphaltum mixed with a little wax or pitch1 or even watchmakers' cement1 used to fasten staffs and pinions into a lathe for turning1 is also used on these dials and with a sufficient proportion of wax or pitch it prevents shrinking and forms a very satisfactory dial with the single exception that it cannot be cleaned with benzine or hot potash1 which will dissolve the enamel4 ,shoemakers' heel ball is also used for repair jobs4 ,in order to make either of these stick1 the brass or copper plate is heated up so as to 8hiss0 as will a laundry flat iron when touched with a wetted finger1 and a cement stick is rubbed over the letters to fill them2 the excess of filling can be scraped off with an ivory scraper when at the right temperature--a little below the boiling point of water4 ,such filled letters can be lacquered over by going very quickly over the work so as not to dissolve the shellac in the cement4 ,another way is to fill the letters with black lacquer4 ,for quick repairs this is probably as good as any4 ,many of the old grandfather clocks have been filled in with a putty made with copal varnish and some black pigment4 ,all putties shrink in drying and consequently crack and finally fall out4 ,the wax and pitch are not subject to these disadvantages4 ,if the plates are to be polished1 polishing should precede the filling in of the letters1 else the work may have to be done all over again4 ,black sealing wax and alcohol are also used1 applied as a paint with a fine brush4 ,if the dial is to be silvered or gilt the blacking should be done first1 and if to be electroplated the blacking should be what is known as the 8platers' resist10 which is composed chiefly of asphaltum and pitch dissolved in turpentine4 ,it is also called 8stopping-off0 varnish1 and has large use in the plating establishments to prevent deposition of metal where it is not desired4 ,the repairer who gets many grandfather clocks will often find that it is necessary to repaint the dial1 generally because of a too vigorous scrubbing1 or because of cracks or scaling1 which the owner may dislike4 ,it is always best1 however1 to be cautious in such matters1 as many people value such a clock chiefly on account of its visible evidences of age and such cracks form generally a large proportion of such evidence4 ,therefore it is best never to touch an antique dial unless the owner desires it4 ,such dials are usually sheet-iron1 and tolerably smooth1 so the metal will need but a few coats of paint to prepare it4 ,for ground coats1 take good1 ordinary white-lead or zinc white1 ground with oil1 and if it has much oil mixed with it pour it off and add spirits of turpentine and ,japan dryer--a teaspoonful of dryer for every half pint of paint4 ,the test for the paint having the right amount of oil left in it is1 it should dry without any gloss4 ,rub every coat you apply with fine sand paper1 after it is perfectly dry1 before applying the next coat of paint4 ,for the final coat1 lay the dial flat and go over it with ,french zinc white4 ,this coat dries very slow1 and for a person not used to such work1 is hard to manage4 ,the next best 7and for ordinary clock or watch making the best7 for the last pure white coat is to take a double tube of ,windsor ,newton's ,kremnitz white1 thinned with a little turpentine4 ,such tubes as artists use are the kind4 ,apply this last white coat with a flat1 camel's hair brush4 ,the tube-white should have turpentine enough added to cause it to flow freely1 and sink flat and smooth after the brush4 ,the letters or figures should be painted with ivory-black1 which is also a tube color4 ,this black is mixed with a little ,japan1 rubbing varnish and turpentine1 and the lettering is done with a small1 sign writer's pencil4 ,any flowers or ornaments are painted on at the same time2 and after they are dry the dial should be varnished with ,mastic or ,damar varnish or white shellac4 ,all kinds of coach 7,copal7 varnish are too yellow4 ,painted dials on zinc will blister and crack off if subjected to extremes of heat and cold1 unless they are painted with zinc white instead of lead for all white coats4 ,the reason is the great difference in expansion between lead paint and metallic zinc4 ,this case is similar to that of using an iron oxide to paint iron work of bridges1 ships1 etc41 where other oxides will chip and scale off4 ,the metal dials on these old clocks were silvered by hand4 ,when you get such a dial1 discolored and tarnished1 it can be cleaned in cyanide and resilvered1 without sending it to an electroplater1 by the following formula3 ,dissolve a stick of nitrate of silver in half a pint of rain water2 add two or three tablespoonfuls of common salt1 which will at once precipitate the silver in the form of a thick1 white curd1 called chloride of silver4 ,let the chloride settle until the liquid is clear2 pour off the water1 taking care not to lose any chloride2 add more water1 thoroughly stir and again pour off1 repeating till no trace of salt or acid can be perceived by the taste4 ,after draining off the water add to the chloride about two heaped tablespoonfuls each of salt and cream of tartar1 and mix thoroughly into a paste1 which1 when not in use1 must not be exposed to the light4 ,to silver a surface of engraved brass1 wash the surface clean with a stiff brush and soap4 ,heat it enough to melt black sealing wax1 which rub on with a stick of wax until the engraving is entirely filled1 care being taken not to burn the wax4 ,with a piece of flat pumice-stone1 and some pulverized pumice-stone and plenty of water1 grind off the wax until the brass is exposed in every part1 the stoning being constantly in one direction4 ,finish by laying an even and straight grain across the brass with blue or water of ,ayr stone4 ,take a small quantity of pulverized pumice-stone on the hand1 and slightly rub in the same direction1 which tends to make an even grain2 the hands must be entirely free from soap or grease4 ,rinse the brass thoroughly1 and before it dries1 lay it on a clean board1 and gently rub the surface with fine salt1 using a small wad of clean muslin4 ,when the surface is thoroughly covered with salt1 put upon the wad of cloth1 done up with a smooth surface1 a sufficient quantity of the paste1 say to a dial three inches in diameter a piece of the size of a marble1 which rub evenly and quickly over the entire surface4 ,the brass will assume a greyish1 streaked appearance2 add quickly to the cloth cream of tartar moistened with water into a thin paste2 continue rubbing until all is evenly whitened4 ,rinse quickly under a copious stream of water2 and in order to dry it rapidly1 dip into water as hot as can be borne by the hands1 and when heated1 holding the brass by the edges1 shake off as much of the water as possible1 and remove any remaining drops with clean1 dry cloth4 ,the brass should then be heated gently over an alcohol lamp1 until the wax glistens without melting1 when it may be covered with a thin coat of spirit varnish1 laid on with a broad camel's hair brush4 ,the varnish or lacquer must be quite light colored--diluted to a pale straw color4 ,it is now possible to buy silver plating solutions which can be used without battery and they will produce the same effect as the formula just given4 ,if they happen to be in stock for the repairing of jewelry they may be used in cleaning the dials1 but as this is liable to fall into the hands of many who are far from such conveniences1 we furnish the original recipe1 which can be executed anywhere the materials can be obtained4 ,if the dial is of brass1 very good effects have been produced by stopping off portions of the dial in an ornamental pattern before silvering1 and then lacquering after removing the resist4 ,but for a plain black and brass dial a dip of strong sulphuric acid two parts1 red fuming nitrous acid one part1 and water one part1 mixed in the open air and dipped or flowed over the dial1 forms what is known as the platers' bright dip4 ,after dipping the article should at once be rinsed in hot water and dried1 and lacquered at once with a lacquer of light gold color4 ,this makes a very neat and durable finish4 ,the satin effect may be obtained on a dial by prolonging the acid dip and otherwise proceeding as before4 ,many of these dials were of zinc and all that applies to brass or copper may be also executed in zinc1 but in plating it will be found necessary to plate two or three times1 as the single coating will apparently disappear into the zinc unless it is given a heavy deposit of copper in a plating bath4 ,where it is desired to obtain a bright gold color1 the gold plating solutions now sold for the coloring of jewelry may also be used on either of these metals4 ,for the reasons given above1 however1 they are not very successful on a zinc base4 ,many of the cheap clocks have paper dials glued on a zinc plate and when the dial is soiled the repairer cleans them up by pasting another dial on top of the original4 ,these dials are made on what is known as lithographic label paper2 that is paper which is waterproof on one side1 so that it will not shrink or swell when dampened4 ,in addition to the lithograph coating they are generally given a varnish of celluloid by the clock manufacturers1 thus making them practically waterproof4 ,they are very cheap and the repairer will find that he will obtain in prestige from such new dials far more than they cost4 ,tarnished metal dials are best cleaned by a dip of cyanide of potassium1 of about the same strength as that used for cleaning silver4 ,if the tarnished parts have been gilded1 however1 the cyanide should be excessively weak4 ,mining men use a cyanide solution for the recovery of gold1 which is only two-tenths of one per cent cyanide1 and this will collect all the gold from ore that runs from #aj to #ae to the ton1 the pulp in such cases being left in the solution from seventy to ninety hours4 ,the ordinary cyanide dip for the jeweler is one ounce to thirty-two of water1 while the miner's solution is two-tenths of an ounce to one hundred ounces of water4 ,you can see that with the strong cyanide solution the gilt surface will all be taken off unless very rapid dipping is strictly followed by thorough washing4 ,a novelty which keeps periodically coming to the front1 say about once every ten years1 is the luminous dial4 ,this is done by painting the dial with phosphorus or a phosphorescent powder4 ,then when it is placed in the light it will absorb light and give it off in the dark until the evaporation of the phosphorus4 ,the composition and manufacture of this phosphorescent powder is effected in the following manner3 ,take #ajj parts by weight of carbonate of lime and phosphate of lime1 produced by calcination of sea-shells1 especially those of the tridacna and cuttlefish bone1 and #ajj parts by weight of lime1 rendered chemically pure by calcination4 ,these ingredients are well mixed together1 after which #be parts of calcinated sea salt are added thereto1 sulphur being afterward incorporated therewith to the extent of from #be to #ej per cent of the entire mass1 and a coloring matter is applied to the composition1 which coloring matter consists of from #c to #g per cent of the entire mass of a powder composed of a mono-sulphide of calcium1 barium1 strontium1 magnesium or other substance which has the property of becoming luminous in the dark1 after having been impregnated with light4 ,after these ingredients are well mixed1 the composition is ready for use4 ,its application to clock dials is made either by incorporating suitable varnish therewith1 such as copal1 and applying the mixture with a brush to the surface of the dial1 or by the production of a dial which has a self-luminous property1 imparted to it during its manufacture4 ,this is effected in the following manner3 ,from #e to #bj per cent of the composition obtained and formed as above described1 is incorporated with the glass while it is in a fused state1 after which the glass so prepared is molded or blown into the shape or article required4 ,another process consists of sprinkling a quantity of the composition over the glass article while hot1 and in a semi-plastic state1 by either of which processes a self-luminous property will be imparted to the article so treated4 ,where enamel dials are chipped the cracks may be hidden by first pressing the cracks very slightly open and washing out4 ,then work in a colorless cement to fill the crack1 allow to dry and stone down4 ,where holes have been left by the chipping1 melt equal parts of scraped pure white wax and zinc white and let it cool4 ,warm the dial slightly and press the cold wax into the defective places and scrape off with a sharp knife and it will leave a white and lustrous surface4 ,if too hard add wax2 if too soft add some zinc white4 ,,varnish ,,for ,,dials1 ,,etc4--,a handsome varnish for the dials of clocks1 watches1 etc41 may be prepared by dissolving bleached shellac in the purest and best alcohol4 ,it offers the same resistance to atmospheric influence that common shellac does4 ,in selecting bleached shellac for this purpose be careful to get that which will dissolve in alcohol1 as some of it being bleached with strong alkalies1 is thereby rendered insoluble in alcohol4 ,the shellac when dissolved should be of a clear light amber color in the bottle and this will be invisible on white paper when dry4 ,colorless celluloid lacquer1 known to jewelers as 8silver lacquer0 on account of its being used to prevent tarnish on finished hollow ware1 also makes a good varnish to apply to dials1 either metallic or painted4 ,it is best to have it thin1 flow it on the dial and then level the dial to dry4 ,success in the repairing of a broken enameled clock dial will greatly depend upon the practical skill of the operator1 as well as of a knowledge of the process4 ,if it is only desired to repair a chipped place on a dial1 a fusible enamel of the right tint should be procured from a dealer in watchmakers' materials1 which1 with ordinary care1 may be fused on the chipped place on the dial so as to give it a workmanlike appearance when finished off4 ,the place to receive the enamel should be well cleaned1 and the moist enamel spread over the place in a thin1 even layer2 and1 after allowing it to dry1 the dial may be held over a spirit lamp until the new enamel begins to fuse1 when it may be smoothed down with a knife4 ,the dial1 after this operation1 is left to cool1 when any excess of enamel may be removed by means of a corundum file1 and subsequently polished with putty powder 7oxide of tin74 ,the ingredients of enamel1 after being fused into a mass1 are allowed to cool1 then crushed to powder and well washed to get rid of impurities1 and the resulting fine powder forms the raw material for enameling4 ,it is applied to the object to be enameled in a plastic condition1 and is reduced to enamel by the aid of heat1 being first thoroughly dried by gentle heat1 and then fused by a stronger one4 ,the following is a good white enamel for dials3 ,silver sand1 #c ounces2 red lead1 #c ounces2 oxide of tin1 #b ounces2 saltpeter1 ounce2 borax1 #b ounces1 flint glass1 #a ounce2 manganese peroxide1 #b grains4 ,the basis of nearly all enamels is an easily fusible colorless glass1 to which the required opacity and tints are given by the addition of various metallic oxides1 and these1 on being fused together1 form the different kinds of vitreous substances used by enamel workers as the raw material in the art of enameling4 ,the hands of timekeepers are worthy of more attention than is frequently bestowed upon them by watch and clockmakers4 ,their shape and general arrangement1 and the neatness of their execution is often taken by the general public as an index to the character of the entire mechanism that moves them2 and some are apt to suppose that when care is not bestowed on the parts of the timepiece which are most seen1 much care cannot be expected to have been exercised on the parts of the watch or clock which are invisible to the general view4 ,although we are not prepared to fully endorse the opinion that when the hands of timepieces are imperfect in their execution1 or in their general arrangement1 all the mechanism must of necessity be imperfect also2 still we think that in many instances there is room for improving the hands of timepieces1 and we desire to direct more attention to this subject by the workmen4 ,in the general arrangement of the hands of watches and clocks1 distinctness of observation should be the great point aimed at1 and everything that has a tendency to lead to confusion should be carefully avoided4 ,clocks that have a number of hands radiating from one center1 and moving round one circle--as for instance1 center seconds1 days of the month1 equation of time1 alarms and hands for other purposes--may show a good deal of mechanical skill on the part of the designer and maker of the timepiece2 but so many hands moving together around one circle1 although they may be of different colors1 causes confusion1 and requires considerable effort to make out what the different hands point to in a dim light1 and this confusion is frequently increased by the necessity for a counterpoise being attached to some of the hands4 ,as a rule timekeepers should be so arranged that never more than the hour and minute hand should move from one center on the dial4 ,there may be special occasions when it is necessary or convenient to have center seconds to large dials2 but these occasions are rare1 and we are talking about the hands of timekeepers in everyday use for the ordinary purposes of life1 and also for scientific uses4 ,in astronomical clocks and watchmakers' regulators we find the hour1 minute and second hands moving on separate circles on the same dial2 and the chief reason for this arrangement is to prevent mistakes in reading the time4 ,in chronometers1 especially those measuring sidereal time1 the hour hand is frequently suppressed1 and the hours are indicated by a star wheel1 or ring1 with figures engraved on it1 that show through a hole in the dial4 ,hour and minute hands should be shaped so that the one can be easily distinguished from the other without any effort on the part of the observer4 ,probably a straight minute hand1 a little swelled near the point1 and a spade hour hand1 are the shapes best adapted for this purpose1 especially if the hands have to be looked at from a distance4 ,there are occasions1 however1 when a spade hand cannot be used with propriety4 ,in small watches and clocks having ornamental cases1 hands of other designs are desirable1 but whatever be the pattern used1 or whatever color the hands may be made1 it should ever be remembered that while a design in harmony with the case is perfectly admissible1 the sole use of hands is to mark the time distinctly and readily4 ,the difference in the length of the hour and minute hands is also an important point in rendering the one easily distinguished from the other4 ,the extreme point of the hour hand should extend so as to just cover the edge of the inside end of the numerals and the extreme point of the minute hand should cover about two-thirds of the length of the minute divisions4 ,hands made of this length will be found to mark the hours and minutes with great plainness1 and the rule will be found to work well in dials of all sizes4 ,as a general rule1 the extreme points of the hands should be narrow4 ,the point of the hour hand should never be broader than the thickest stroke of any of the numerals1 and the extreme point of the minute hand never broader than the breadth of the minute lines2 and in small work it is well to file the ends of the hands to a fine point4 ,the ends of minute hands should in every instance be bent into a short1 graceful curve pointing toward the dial1 and as close to it as will just allow the point of the hand to be free4 ,the minute hands of marine chronometers are invariably bent in this manner1 and the hands of these instruments are usually models of neatness and distinctness4 ,balancing hands by means of a counterpoise is a subject which requires some attention in order to effect the perfect poise of the hand without detracting anything from its distinctness4 ,in watch work1 and even in ordinary clock work1 it seldom happens that any of the hands except the seconds require to be balanced1 and then there is only one hand moving round the same circle1 as is the case with seconds hands in general4 ,we have become so accustomed to looking at seconds hands with projecting tails that we are apt to regard the appearance of the hands to be incomplete without the usual tail2 but we must remember that the primary object in view in having a tail to a seconds hand is to counterpoise it1 not to improve the looks of the hand itself4 ,poising becomes an actual necessity for a hand placed on so sensitive a part as the fourth wheel of a watch1 or on the scape wheel of a fine clock4 ,when only one hand moves in the same circle1 like a seconds hand1 the counterpoise may be effected by means of a projecting tail without in any way detracting from a distant reading of the hands1 providing the tail is not made too long1 and it is made of such a pattern that the one end can easily be distinguished from the other4 ,in minute and hour hands1 however1 it is different4 ,these two hands move round the same circle1 and a counterpoise on the minute hand is liable at a distance to be mistaken for the hour hand4 ,the minute hands of large timepieces frequently require to be balanced1 especially if the dial be large in comparison to the size of the movement2 and in very large or tower clocks1 whatever may be the size of the movement1 it becomes an absolute necessity to balance the hands4 ,in our opinion1 tails should never be made on minute hands1 when they can be avoided1 and in cases where tails cannot be dispensed with1 they should invariably be colored the same as the ground of the dial4 ,in almost every instance1 however1 minute hands may be balanced in the inside1 as is usual with tower clocks4 ,a great many clocks used for railway and similar purposes in ,europe have their minute hands balanced in this manner1 and the plan works admirably2 for in addition to rendering the hands more distinct1 the clocks require less power to keep them going than when the hands are balanced from the outside4 ,illustration3 ,fig4 #aej4 ,showing counterpoise on arbor of minute hand in tower clock4 ,tower clock hands are generally made of copper1 elliptical in section1 being made up of two circular segments brazed together at the edges1 with internal diaphragms to stiffen them4 ,the minute hand is straight and perfectly plain1 with a blunt point4 ,at the center of the dial the width of the minute hand is one-thirteenth of its length1 tapering to about half as much at the point4 ,the hour hand is about the same width1 ending just short of the dial figure and terminating in a palm or ornament4 ,the external counterpoises are one-third the length of the minute hand1 and of such a shape that they will not be confounded with either of the hands2 a cylinder1 painted the same color as the dial1 and loaded with lead1 makes a good counterpoise4 ,this counterpoise may be partly on the inside of the dial if it is desired to keep it invisible1 but it should not be omitted1 as it saves a good deal of power1 prevents the twisting of the arbors1 and also assists in overcoming the action of the wind on the hands4 ,two-thirds of the counterpoise weight may be inside1 as shown in ,fig4 #aej4 ,,to ,,blue ,a ,,clock ,,hand ,,or ,a ,,spring4--,to blue a piece of steel that is of some length1 a clock hand for example1 clockmakers place it either on ignited charcoal1 with a hole in the center for the socket1 and whitened over its surface1 as this indicates a degree of heat that is approximately uniform1 or on a curved bluing tray perforated with holes large enough to admit the socket4 ,the center will become violet or blue sooner than the rest1 and as soon as it assumes the requisite tint1 the hand must be removed1 holding it with tweezers by the socket1 or by the aid of a large sized arbor passed through it2 the lower side of the hand is then placed on the edge of the charcoal or bluing tray1 and removed by gradually sliding it off toward the point1 more or less slowly1 according to the progress made with the coloring2 with a little practice1 the workman will soon be enabled to secure a uniform blue throughout the length and even1 if necessary1 to retouch parts that have not assumed a sufficiently deep tint4 ,instead of a bluing tray1 a small mass of iron1 with a slightly rounded surface and heated to a suitable temperature1 can be employed2 but the color must not form too rapidly1 and this is liable to occur if the temperature of the mass is excessive4 ,nor should this temperature be unevenly distributed4 ,a spring1 after being whitened1 can be blued in the same way4 ,having fixed one end1 it is stretched by a weight attached to the other end1 and the hot iron is then passed along it at such a speed that a uniform color is secured4 ,of course1 the hot iron might be fixed and the spring passed over it4 ,a lamp may be used1 but its employment involves more attention and dexterity4 ,,chapter ,,xxiii4 ,,clock ,,casing ,,and ,,case ,,repairs4 ,,precision ,,clock ,,cases4--,the casing of a precision clock is only secondary in importance to the compensation of its pendulum4 ,the best construction of an efficient case can be ascertained only by most careful study of the conditions under which the clock is expected to be a standard timekeeper1 and often the entire high accuracy sought by refined construction is sacrificed by an inefficient case and mounting4 ,the objects of casing a precision clock are as follows3 a4 ,to protect the mechanism from the effects of dust and dirt4 b4 ,to avoid changes of temperature and barometric pressure4 c4 ,to provide an enclosed space in which the gas medium in which the pendulum swings shall have any chemical constitution1 of any hygroscopic condition4 d4 ,there must be provided ready means of seeing and changing the condition of the pendulum1 electric apparatus1 movement1 etc41 without disturbing the case except locally4 ,now if we hold the above considerations in view we can readily see that cast iron1 wood and glass1 with joints of wash leather 7which is kept soft by a wax cement which does not become rancid with age71 are the preferable materials4 ,the advantages of using cast iron for the pillar or body of the case are that it can be cast in such a shape as to require very little finishing afterwards1 and that only such as planing parallel surfaces in iron planing machines4 ,it makes a stiff column for mounting the pendulum when it rests upon a masonry foundation from below4 ,plates of glass can be clamped against the planed surfaces of iron piers 7by putting waxed wash leather between the glass and the iron7 so as to make air-tight joints without difficulty4 ,the mass of iron symmetrically surrounding the steel pendulum is the safest protection the clock can have against casual magnetic disturbances4 ,in the language of electricians it 8shields0 the pendulum4 ,suppose1 then1 we adopt as the first type of precision clock case which our present knowledge suggests1 that of an iron cylinder or rectangular box resting on a masonry pier1 and which has a table top to which the massive pendulum bracket is firmly bolted4 ,this type admits of the weights being dropped in small cylinders outside of the cast iron cylinder or box4 ,these weight cylinders1 of course1 end in the table top of the clock case above and in the projecting base of the flange of the clock case below4 ,with this construction it is a simple matter to cover the movement with a glass case1 preferably made rectangular1 with glass sides1 ends and top1 with metal cemented joints4 ,the metal bottom1 edges of this rectangular box can be ground to fit the plane surface of the top of the clock case4 ,then1 by covering the bottom edges with such a wax as was used in making the glass plates fit the iron case in front or back1 we can secure an air-tight joint at the junction of the rectangular top glass case with iron case4 ,in practice the wax to be used may be made by melting together and stirring equal parts of vaseline and beeswax4 ,the proportions may be varied to give a different consistency of wax1 and it may be painted on with a brush after warming over a small flame4 ,if the clock case will be exposed to a comparatively high temperature1 say #ie ,f41 then the beeswax can be #c parts to #a of vaseline4 ,the good quality of this cement wax is that it does not change with age1 or at least for several years1 is very clean1 and can be wiped off completely with kerosene1 or turpentine1 or benzine4 ,in all joints meant to be air-tight1 the use of rubber packing is to be avoided4 ,it answers well enough at the start1 but after several months it is sure to crack and leak air4 ,by an air-tight joint ,i do not mean a joint which will not leak air under any pressure which may be applied4 ,it is not necessary that our pendulum should vibrate in a vacuum2 all we want is that the pressure inside the clock case should be uniform2 that it should not vary with the barometer outside4 ,in actual practice we find it best to have the pressure inside the case as nearly as possible equal to the average atmospheric pressure outside4 ,now1 if the barometer in a given locality never sinks below #bg4e inches1 it is not necessary that the vacuum in the clock case be less than that represented by #bi4e inches of mercury pressure4 ,so1 too1 if it were desirable to have the pressure inside the case greater than that outside1 owing to some special form of joint which made the clock case less liable to leak out than to leak in1 it might be that an inside pressure would be efficient at #ca inches of mercury4 ,by not having the inside pressure vary but slightly from the outside1 the actual pressure of air will not exceed one inch of mercury1 or1 say1 pound pressure to the square inch4 ,this is a pressure which causes quite an insignificant strain upon any joint4 ,there are objections1 however1 to the use of air in an enclosed space for precision clocks and so the attempt has been made to use hydrogen4 ,air is1 comparatively speaking1 heavy4 ,it is #ad times as heavy as hydrogen gas1 for instance4 ,the pendulum1 therefore1 in moving through its arc has to push aside #ad times as much weight as it would have to in case it were surrounded by hydrogen4 ,then what might be called the 8case friction0 is greater than if we used hydrogen4 ,by 8case friction0 ,i mean resistance and a disturbance to the pendulum depending on the effect of the currents of air produced by driving the air before the pendulum against the sides and front of the case4 ,it is a well-established observation that small1 cramped cases disturb the clock's rate more than large1 roomy ones4 ,this is because the air1 having no room to go before the pendulum1 is cushioned up against the side of the case at each pendulum swing1 and acts as a resisting spring against the swing of the pendulum4 ,by the time the pendulum has reached the end of its vibration the air has escaped upwards and downwards perhaps so that it no longer has its spring power to restore the loss of energy to the pendulum4 ,this 8case friction0 is most pernicious in its action when associated with free falling weights in the clock case4 ,clock weights should always fall in separate compartments1 and never in such a manner that they can affect the space in which the pendulum swings4 ,but this is a digression to explain the term 8case friction0 in its use in horology4 ,precision clocks1 almost without exception1 have electric break-circuit attachments within the case4 ,most of these break-circuits are constructed so that there is a small spark every time the circuit is broken4 ,the effect of such a spark in air is to convert a small portion of the air in the immediate neighborhood of the spark into nitrous acid gas4 ,after several months there might be a considerable quantity of this gas in the case1 with the certain result of rusting the nicer parts of the escapement4 ,many attempts have been made to run a clock in an almost complete vacuum of air2 but the volume to be exhausted is so large1 and the leakage is so sure to occur after a time1 that the attempt is now pretty generally abandoned4 ,it will be inferred from what has preceded that a full atmosphere of hydrogen would only offer one-fourteenth the resistance to the pendulum that air would1 and all the disturbances arising from the surrounding mediums would be only one-fourteenth for hydrogen of that which we would expect for air4 ,every consideration1 therefore points to the use of hydrogen as the medium with which to fill our clock cases4 ,it is inert1 it forms no compounds under the influence of the electric spark1 the case friction is no greater than would exist if we made an air vacuum of only about #a inch of mercury1 and hydrogen gas may be readily prepared4 ,the method from dilute sulphuric acid and scrap zinc is the handiest1 and it will be found described in almost any chemistry textbook or encyclopedia4 ,should the horologist wish to know something of the chemistry of the process1 without previous study1 he will find it described in very simple language in any primary chemistry4 ,the practical details of filling a clock case with hydrogen gas ,i have not yet worked out4 ,it is evident that since hydrogen is #ad times lighter than air1 that by attaching a small tube to the source of hydrogen and to the top of the clock case1 and another small outlet tube at the bottom of the clock case1 that by gravity alone the hydrogen would fill the upper part of the case and drive the air before it out at the bottom4 ,the hydrogen should be dry4 ,to insure this it should pass through a tube containing quicklime1 which1 if it is a foot long and two inches in diameter1 will be sufficient4 ,no burning light or electric spark must be put into the case while filling1 because the mixture of hydrogen with the air is very explosive when ignited4 ,great care must be used in making all joints when attempting to maintain an atmosphere of hydrogen as it leaks readily through the pores of wood iron and all joints4 ,it is1 therefore1 better to treat the case friction as a constant element and simply keep it constant4 ,the above discussion has not considered the temperature question4 ,it is important that the changes of temperature in a clock case should be as slow as possible and as small as possible4 ,professor ,rogers1 of the ,harvard ,college ,observatory1 has shown that such bars as are used in pendulum rods of clocks are often several hours in taking up air temperatures many degrees different from that in which they were swinging4 ,we have at the top of the pendulum a thin spring for suspension whose temperature decides its molecular friction2 then we have the pendulum rod1 and lastly the large bob1 all of which take up any new temperature with different degrees of slowness4 ,now obviously no compensation can be made to act unless the temperatures are the same for all parts of the pendulum1 and vary at the same rate4 ,a number of years ago1 there was a long discussion as to the temperature at the top and bottom of clock cases4 ,it was shown that this regularly amounted to several degrees in the best clocks4 ,it was to lessen this difference that at the ,harvard ,college ,observatory the ,bonds built a deep well in the cellar1 purposing to put the clock at its bottom4 ,the idea was a good one1 and were it not for the difficulty in getting at clocks in wells1 and keeping water out1 it would doubtless find favor where the utmost accuracy is desired4 ,a better plan is to run the clock at a high temperature1 say #ie to #ajj ,f4 ,the oil is more liquid1 the temperature can be more easily maintained1 it can all take place in lighted1 dry rooms1 and the means for doing this we shall now consider4 ,illustration3 ,fig4 #aea4 ,section through clock room of the ,waltham ,watch ,company4 ,our iron case must now be housed in another outside case1 which had better be of wood1 with glass windows for seeing the clock face4 ,a single thickness of wood would conduct heat too rapidly4 ,it must therefore be made of two thicknesses1 with an air space between4 ,if the air space is left unfilled1 the circulation of the air soon causes the inner wooden layer to be of the same temperature as the outer4 ,it is necessary to prevent this circulation of air therefore by means of some substance which is a non-conductor of heat and which will prevent the air from circulating4 ,the very best thing to be used in this connection is cotton batting1 which has been picked out until it is as light and fibrous as possible4 ,then if the doors and windows of the wooden case are made of two thicknesses of extra thick glass1 and are firmly clamped1 by screws through their sashes or some other means1 to the frame of the case1 we have the best form possible for our completed case of the type ,i have described4 ,it now remains to provide a layer of hot water pipes inside the clock room1 heated by circulating hot water from the outside4 ,the flame under the water tank outside1 whether of gas or kerosene1 to be automatically raised or lowered by any such thermostat arrangements as are in common use with chicken incubators1 when the temperature varies from the point desired4 ,experience teaches that the volume of water had better be considerable1 if there is considerable difference in the annual variations of temperature according to the seasons4 ,thus in ,massachusetts or ,illinois the temperature is likely to vary from -#cj ,f4 to #aaj ,f41 and the heating arrangements must be suitable to take care of this variation4 ,the ,waltham ,watch ,company's clock room is an excellent example of the means taken to secure uniformity of temperature and absence of vibration4 ,the clock room1 which is located in the basement of one of the buildings1 is built with a double shell of hollow tile brick4 ,the outer shell rests upon the floor of the basement1 and its ceiling is within two or three inches of the basement ceiling4 ,the inner shell is #aj feet square and #h feet in height1 measured from the level of the cellar floor4 ,there is an #ah-;inch space between the walls of the inner and outer shell and a #i-;inch space between the two ceilings4 ,on the front of the building the walls are three feet apart to accommodate the various scientific instruments1 such as the chronograph1 barometer1 thermostat1 level-tester1 etc4 ,the inner house is carried down four feet below the floor of the basement1 and rests upon a foundation of gravel4 ,the walls of the inner house below the floor level consist of two thicknesses of brick with an air space between1 and the whole of the excavated portion is lined1 sides and bottom1 with sheet lead1 carefully soldered to render it watertight4 ,at the bottom of the excavation is a layer of #ab inches of sand1 and upon this are built up three solid brick piers1 measuring #c feet #f inches square in plan by #c feet in height1 which form the foundation for the three pyramidal piers that carry the three clocks4 ,the interior walls and ceilings and the piers for the clocks are finished in white glazed tiling4 ,the object of the lead lining1 of course1 is to thoroughly exclude moisture1 while the bed of sand serves to absorb all waves of vibration that are communicated through the ground from the various moving machinery throughout the works4 ,at the level of the basement floor a light grating provides a platform for the use of the clock attendants4 ,although the placing of the clock room in the cellar and the provision of a complete air space around the inner room would1 in itself1 afford excellent insulation against external changes of temperature1 the inner room is further safeguarded by placing in the outer #ah-;inch space between the two walls a lamp which is electrically connected to1 and controlled by1 a thermostat4 ,the thermostat consists of a composite strip of rubber and metal1 which is held by a clamp at its upper end and curves to right or left under temperature changes1 opening or closing1 by contact points at the lower end of the thermostat1 the electrical circuit which regulates the flame of the lamp4 ,the thermostat is set so as to maintain the space between the two shells at a temperature which shall insure a constant temperature of #ga degrees in the inner clock house4 ,this it does with such success that there is less than half a degree of daily variation4 ,the two clocks that stand side by side in the clock room serve to keep civil time1 that is to say1 the local time at the works4 ,the clock to the right carries a twelve-hour dial and is known as the mean-time clock4 ,by means of electrical connections it sends time signals throughout the whole works1 so that each operative at his bench may time his watch to seconds4 ,the other clock1 known as the astronomical clock1 carries a twenty-four-hour dial1 and may be connected to the works1 if desired4 ,these two clocks serve as a check one upon the other4 ,they were made at the works and they have run in periods of over two months with a variation of less than #j4c of a second1 or _/ part of a day4 ,the third clock1 which stands to the rear of the other two1 is the sidereal clock4 ,it is used in connection with the observatory work1 and serves to keep sidereal or star time4 ,the rate1 as observed at the ,waltham works1 rarely exceeds one-tenth of a second per day4 ,that is to say1 the sidereal clock will vary only one second in ten days1 or three seconds in a month4 ,the variation1 as found1 is corrected by adding or subtracting weights to or from the pendulum1 the weights used being small disks1 generally of aluminum4 ,summing up1 then1 we find that the great accuracy obtained in this clock room is due to the careful elimination of the various elements that would exercise a disturbing influence4 ,changes of temperature are reduced to a minimum by insulation of the clock house within an air space1 in which the temperature is automatically maintained at an even rate4 ,changes of humidity are controlled by the specially designed walls1 by the lead sheathing of the foundation pit1 by the preservation of an even temperature1 and by placing boxes of hygroscopic material within the inner chamber4 ,errors due to vibration are eliminated by placing the clocks on massive masonry piers which stand upon a bed of sand as a shock-absorbing medium4 ,the astronomical clock is inclosed in a barometric case1 fitted with an air pump1 by which the air may be exhausted and the pendulum and other moving parts relieved from barometric disturbances4 ,for it must be understood that variation in barometric pressure means a variation in the density of the air1 and that the speed of the pendulum must necessarily be affected by such changes of density4 ,,restoring ,,old ,,cases4--,very often the watchmaker gets a clock which he knows will be vastly improved by varnish1 but not knowing how to take off the old varnish he simply gives it a little sand paper or rubs it off with oil and lets it go at that4 ,varnishing such a clock thinly with equal parts of boiled oil and turpentine and allowing it to dry will often restore the transparency of the varnish2 if uneven results are obtained a second coat may be necessary4 ,many of these old clocks have not been varnished for so many years that the covering of the wood looks like a cheap brown paint4 ,to remove this in the ordinary way means endless labor1 and if the case is inlaid with colored patterns of veneers1 which are partly loosened by the glue drying out1 the repairer is afraid to touch it for fear he will only make matters worse in the attempt to better them4 ,in the case of an old clock of inlaid marquetry1 if the pieces of veneer have become partly loosened1 the first thing to do is to make a thin1 fresh glue4 ,work the glue under the veneer and then clamp it down tightly with a piece of oiled paper1 or waxed paper1 laid between the glue and the board used to clamp with and the whole firmly set down tight with screws or screw clamps4 ,to make waxed paper dissolve parafine wax in benzine and flow or brush on the paper and let dry4 ,after the glue has hardened comes the work of removing the varnish4 ,to do this you will need some varnish remover1 which can either be bought at the paint store1 or made as follows3 ,,varnish ,,remover4--,in doing such work the trick is to make sure that nothing put on the case will injure it1 as a clock one hundred years old cannot be replaced4 ,therefore1 if you are suspicious as to the varnish removers you can purchase1 and do not want to take chances1 you may make one of wood alcohol and benzole1 or coal tar naphtha4 ,be sure you do not get petroleum naphtha1 which is common gasoline4 ,the coal tar naphtha is a wood product4 ,the wood alcohol is also a wood product and the varnishes used upon furniture are vegetable gums1 so that it will readily be seen that you are putting nothing on the antique with which it was not associated in its natural state4 ,equal parts of benzole and wood alcohol will dissolve gums instantaneously1 so that if the oil has dried out of the varnish so much that the varnish has become opaque and only the rosins are left1 the application of this fluid with a brush will cause instant solution1 making the gums boil up and form a loose crust upon the surface of the wood1 as the liquid evaporates1 which it does very rapidly4 ,varnishes containing shellac and some other gums are rather hard to dissolve and where an obstinate varnish is encountered it may be well to use wax in the varnish remover4 ,this is done by shaving or chopping some parafine wax1 dissolving it in the benzole1 and when it is clear and transparent1 add the wood alcohol4 ,upon the addition of the alcohol the wax immediately curdles so that the fluid becomes milky4 ,in this condition it is readily brushed upon any surface and when the wax strikes the air it congeals and forms a crust which holds the liquid underneath and enables it to do its work instead of evaporating4 ,the wax also serves the purpose of allowing the workman to see just where he is putting his fluid and of holding it in position upon vertical surfaces or ceilings1 round moldings1 carved work and other places from which it will quickly run off4 ,only enough wax should be added to make it spread readily with the brush and after soaking it will be an easy matter to take a painter's putty knife1 a case knife1 or a scraper and laying it nearly flat on the wood remove all the varnish at one operation1 wiping off the knife as fast as it becomes too full4 ,after the bulk of the varnish is off some of the fluid1 without the wax1 may be used upon a cloth to go over and smooth up by removing the spots and stripes of varnish left by the knife1 or in moldings1 etc41 where the knife cannot be applied1 and we have our bare wood1 which1 after drying and sand papering1 is ready for a fresh coat of ,,xxx coach varnish1 which should dry in #bd hours and harden in a week4 ,a very little work and practice in this will enable the workman to rapidly and cheaply clean up and repair antiques in such a way that it will add greatly to his reputation4 ,to restore the gloss of polished wood it is not always the best plan to employ true furniture polish4 ,the majority of the so-called polishes for wood are based on a mixture of boiled linseed oil and shellac varnish1 made by dissolving shellac in alcohol in the proportion of four ounces of shellac to a pint of alcohol4 ,a little of the dissolved shellac is poured on to a canton-flannel rag1 a few drops of the boiled linseed oil are placed on the cloth1 and the wood to be polished is rubbed vigorously4 ,about half an ounce of camphor gum dissolved with the shellac in the alcohol will greatly facilitate the operation of polishing4 ,a soft woolen rag1 moistened with olive oil and vigorously rubbed on dull varnished surfaces1 like old clock cases1 will brighten the surface wonderfully4 ,some workmen add a few drops of a strong solution of camphor gum in alcohol to the olive oil4 ,the polishing of cases is accomplished by applying several coats of the best coach painters' rubbing varnish1 when1 after perfect drying1 the surface is rubbed with a felt or a canton-flannel rag1 folded flat1 using water and the finest pulverized pumice-stone4 ,this operation smooths the surfaces4 ,the final polishing of such work is done by rubbing with rotten stone and olive oil with the smooth side of canton flannel4 ,to remove the last traces of smear caused by the oil1 an old1 soft linen cloth and rye flour is used4 ,of course1 fine work like we see on new cases of fine quality is not likely to be produced by one who is unaccustomed to it2 a man must serve a good1 long apprenticeship in the varnish finishing business before he is competent for it2 and even then some polishers fail to obtain the fine results achieved by others4 ,the great danger is that the rubber will cut through the varnish and expose the bare wood on edges1 corners and even in spots on plane surfaces1 before he has removed the lumps and streaks of varnish on adjacent portions of the work4 ,whenever the varnish is flat and smooth in any spot1 you must stop rubbing there4 ,black wood clocks which have become smoked and dull should have the cases rubbed with boiled oil and turpentine on a piece of soft woolen rag2 afterwards polish off with a dry rag4 ,if the gloss has been destroyed it will have to be varnished4 ,flow the varnish well on and use #a-;inch brush and be careful to get the varnish on even and so as not to trickle4 ,this is easy if you are careful to keep the varnish thin and do not go over the varnish a second time after spreading it on4 ,thin with turpentine and put very little on the case2 it is already smooth and a mere film will give the gloss4 ,for white filling on the engraving on black cases use ,chinese white or get a good white enamel at a paint store4 ,gilding on wood cases is done by mixing a little yellow dry color with thin glue and painting the cases with the mixture2 the color lets you see what you are doing4 ,when the glue has dried until it is 8tacky10 lay gold leaf on the painted portions and smooth down with cotton4 ,if you have any holes do not attempt to patch them4 ,it is easier and quicker to put on another sheet of gold leaf over the first one4 ,after the gold is dry1 it may be burnished with a bloodstone or smooth steel burnisher1 or it may be left dead4 ,finish with colorless lacquer1 very thin and smooth4 ,imitation gold leaf1 known to the trade as ,dutch ,metal1 may be substituted for the gold leaf1 if the latter is thought to be too expensive1 but in such cases be sure to have the metal well covered with the lacquer1 as unless this is done it will blacken in two or three years--sometimes in two or three months4 ,bronze powder may be applied to the glue size with a tuft of cotton and well rubbed in until flat and smooth2 then lacquer and dry4 ,never put on bronze paint1 for the following reason3 ,if we examine the bronze under a microscope we shall find that it is composed of flat scales like fish scales2 if mixed as a paint they will be found lying at all angles in the painted work--many standing on edge4 ,such scales reflect the light away from the eye and make the work look dull and rough4 ,if we rub these dry scales in gently on the sticky size1 we will lay them all down flat and smooth1 so that the work will glisten all over with an even color4 ,always lacquer bronzed work--yellow lacquer being the best--and put on plenty of lacquer4 ,metal ornaments1 when discolored1 should be removed from the case1 dipped in boiling lye to remove the lacquer1 scratch brushed1 dipped in ammonia to brighten1 rinsed in hot water and dried in sawdust4 ,they may then be lacquered with a gold lacquer1 or plated in one of the gold plating solutions sold by dealers for plating without a battery and then lacquered1 if bright4 ,if they are of oxidized finish cleaning and lacquering is generally all that is necessary4 ,oxidized metal cases1 if badly discolored1 should be sent to an electroplater to be refinished1 as the production of smooth and even finishes on such cases1 requires more skill than the clock repairer possesses1 and he therefore could not do a good job1 even if he had the necessary materials and formul4 ,marble cases are made of slabs1 cemented together4 ,many workmen use plaster of paris by merely mixing it with water1 though we rather think it better to use glue in the mixing1 as plaster so mixed will not set as quickly as that mixed with water4 ,after the case is cemented with the plaster1 the workman can go over the joint with a brush and water colors1 and with a little care should be able to turn out a job in which the joint will not be noticeable4 ,another cement much used for marble is composed of the white of an egg mixed with freshly slaked lime1 but it has the disadvantage of setting very quickly4 ,marble case makers use a cement composed of tallow1 brick dust1 and resin melted together1 and it sets as hard as stone at ordinary temperatures4 ,it often happens that the marble case of a mantel clock is injured by some accident and its corners are generally the first to suffer4 ,if the break is not so great as to warrant a new case or a new part the repairer may make the case a little smaller or file until the edges are reproduced1 after which the polish is restored4 ,proceed as follows3 ,take off from the damaged part as much as is necessary by means of a file1 taking care however1 not to alter the original shape of the case4 ,now grind off the piece worked with the file with a suitable piece of pumice-stone and water and continue the grinding next with a water stone until all the scratches have disappeared1 paying special attention to the corners and contours4 ,after this has been done take a hard ball of linen1 moisten it1 and strew over it either tripoli or fine emery and proceed to polish the case with this4 ,finish the polishing with another linen ball1 using on it still finer emery and rouge4 ,now dry the case and finish the polishing with a mixture of beeswax and oil of turpentine4 ,this method may be employed for all kinds of marble1 or onyx and alabaster cases4 ,in cases where the fractures are very deep1 so that the object cannot be made much smaller without ruining the shape1 the damaged parts may be filled with a cement1 prepared from finely powdered marble dust and a little isinglass and water1 or fish glue will answer very well4 ,stir this into a thick paste1 which fill into the deep places and permit to dry2 after drying1 correct the shape and polish as described4 ,if the pieces which have been broken off are at hand they may be cemented in place again4 ,wet the pieces with a solution of water and silicate of potash1 insert them in place and let them dry for forty-eight hours4 ,if the case is made of white marble use the white of an egg and a little ,vienna lime1 or common lime will answer4 ,,to ,,polish ,,marble ,,clock ,,cases4--,it frequently becomes the duty of the repairer to restore and polish marble clock cases1 and we would recommend him to make a thin paste of the best beeswax and spirits of turpentine1 clean the case well from dust1 etc41 then slightly cover it with the paste1 and with a handful of clean cotton1 rub it well1 using abundant friction1 finish off with a clean old linen rag1 which will produce a brilliant black polish4 ,for light colored marble cases1 mix quicklime with strong soda water1 and cover the marble with a thick coating4 ,clean off after twenty-four hours1 and polish well with fine putty powder4 ,,to ,,remove ,,oil ,,spots ,,from ,,marble4--,oil spots1 if not too old1 are easily removed from marble by repeatedly covering them with a paste of calcined magnesia and benzine1 and brushing off the magnesia after the dissipation of the oil2 this may have to be repeated several times4 ,another recipe reads as follows3 ,slaked lime is mixed with a strong soap solution1 to the consistency of cream2 this is placed upon the oil spot1 and repeated until it has disappeared4 ,in place of this mixture1 another one may be used1 consisting of an ox gall1 #abe grains of soapmaker's waste lye and #fb grams of turpentine1 with pipe clay1 to the consistency of dough4 ,,cutting ,,clock ,,glasses4--,you will sometimes want a new glass for a clock4 ,i get a lot of old #e #g negatives and scald the film off in plain hot water1 rinse well and dry4 ,now ,i lay my clock bezel on a piece of paper and trace around with a pencil1 inside measure4 ,now remove the bezel and trace another circle around the outside of this circle about one-eighth inch4 ,now1 lay the paper on a good1 solid1 smooth surface1 glass on top1 and with a common wheel glass-cutter follow around the outside line1 free handed1 understand4 ,the paper with marked circle on is under the glass1 and you can see right through the glass where to follow with the cutter4 ,now cut the margins of glass so as to roughly break out to one-half inch of your circle cut1 running the cuts out on the side1 then carefully break out4 ,,chapter ,,xxiv4 ,,some ,,hints ,,on ,,making ,a ,,regulator4 ,of all the instruments used by a watchmaker in the prosecution of his business1 there is probably none more important than his regulator4 ,its purpose is to divide time into seconds1 and it is the standard by which the practical results of his labors are tested2 the guide which all the other timekeepers in his possession are made to follow and the arbitrator which settles all disputes regarding the performance of his watches4 ,no regulator has yet been constructed that contains within itself every element for producing absolutely accurate timekeeping4 ,at intervals they must all be corrected from some external source1 such as comparison with another timekeeper1 the error of which is known1 or by the motion of the heavenly bodies1 when instruments for that purpose are available4 ,before beginning to make a regulator1 the prudent watchmaker will first reflect on the various plans of constructing all the various details of an accurate timekeeper1 and select the plan which1 in his opinion1 or in the opinion of those whom he may consult on the subject1 will best accomplish the object he has in view4 ,in former years a regulator case was made with the sole object of accommodating the requirements of the regulator1 and every detail in the construction of the case was made subservient to the necessities of the clock4 ,the plain1 well made cases of former years are now almost discarded for those of more pretentious design4 ,if the general change in the public taste demands so much display1 there can be no objection4 ,it is perfectly harmless to the clock1 if the designers and makers of the cases would only remember that narrow waists or narrow necks on a case1 although part of an elegant design1 do not afford the necessary room for the weight and freedom of the pendulum2 that the doors and other openings in the case must be constructed with a view to exclude dust2 and that the back should be made of thick1 well-seasoned hardwood1 such as oak or maple1 so as to afford the means of obtaining as firm a support for the pendulum as possible4 ,when a regulator case is known to have been made by an inexperienced person1 which sometimes happens1 or when we already have a case1 it is always the safest course for those who make the clock to examine the case personally and see the exact accommodation there is for the clock4 ,sometimes1 when we know beforehand1 we can1 without violating any principle1 vary the construction a little1 so as to make the weight clear the woodwork of the inside of the case1 and in other respects complete the regulator in a more workmanlike manner by making the necessary alterations in the clock at the beginning of its construction1 instead of after it has been once finished agreeably to some stereotyped arrangement4 ,the arrangement of the mechanism of an ordinary regulator is a simple operation compared with some other horological instruments of a more complex character4 ,we are not limited in room to the same extent as in a watch1 and the parts being few in number a regulator is more easily planned than timekeepers having striking or automatic mechanism for other purposes combined with them2 yet it often happens that the inexperienced make serious blunders in planning a regulator1 and1 as the clock approaches completion1 many errors make themselves visible1 which might have been avoided by the exercise of a little more forethought4 ,it may be that1 when the dial is being engraved1 the circles do not come in the right position1 or the weight comes too close to the pendulum1 or the case1 or the cord comes against a pillar1 or other faults of greater or less importance appear1 all of which might have been obviated by taking a more comprehensive view of the subject before beginning to make the clock4 ,the best way to do this is to draw a plan and side and front elevations to a scale4 ,illustration3 ,fig4 #aeb4 ,the position which the barrel and great wheel should occupy is worthy of serious consideration4 ,in most of the cheap regulators1 as well as in a few of a more expensive order1 the barrel is placed in a direct line below the center wheel1 as is shown in ,fig4 #aeb4 ,this arrangement admits of a very compact movement1 and it also allows the weight to hang exactly in the center of the case1 which some think looks better than when it hangs at the side1 especially when there is a glass door in the body of the case4 ,but while a weight hanging in the center of a case may be more pleasing to the eye than when it hangs at the side1 this is an instance where looks can1 with great propriety1 be sacrificed for utility1 because when the weight hangs in the center it comes too close to the pendulum1 and is very liable to disturb its motion4 ,in proof of this statement1 let any reader who has a regulator with a light pendulum and a comparatively large weight hanging in front of it1 closely watch the length of the arc the pendulum vibrates when the weight is newly wound up and when it is down opposite the pendulum ball1 and he will observe that the length of vibration of the pendulum varies from five to fifteen minutes of arc1 according to the position in which the weight is placed2 that the pendulum will vibrate larger arcs when the weight is above or below the ball than when it is opposite it2 and if the clock has a tendency to stop from any cause1 that it will generally do so more readily when the weight is opposite the pendulum ball than when it is in any other position4 ,for this reason ,i would dispense with the symmetrical looks of the weight hanging in the center of the case1 which1 after all1 is only a matter of taste1 and construct the movement so that the weight will hang at the side1 and as1 far away from the pendulum as possible4 ,fig4 #aec is intended to represent the effect which placing the barrel at either side has on throwing the weight away from the pendulum4 ,a is the center wheel2 ,b and ,c are the great wheels and barrels with weights hanging from them2 ,d is the pendulum4 ,it will be noticed by the diagram that the weight at the left of the pendulum is exactly the diameter of the barrel farther away from the pendulum than the weight on the right4 ,on close inspection it will also be observed that on the barrel ,c the force of the weight is applied between the axis of the barrel and the teeth of the wheel1 while on the barrel ,b the axis of the barrel lies between the point where the force is applied and the point where the teeth act on the pinion2 consequently a little more of the effective force of the weight is consumed by the extra amount of pressure and friction on the pivots of the barrel ,b than there is in ,c4 ,illustration3 ,fig4 #aec4 ,notwithstanding this disadvantage1 ,i would for a regulator recommend the barrel to be placed at the left side of the center wheel1 because the weight may thereby be led a sufficient distance from the pendulum in a simple manner4 ,if we place the barrel at the right1 and thereby secure the greatest effective force of the weight1 and then lead the weight to the side by a pulley1 we will lose a great deal more by the friction of the pulley than we gain by the proper application of the weight4 ,in a regulator with a ,graham escapement but little force is required to keep it going1 and there is usually accommodation for an abundance of power2 therefore we cannot use a little of this superabundant available force to better advantage than by placing the barrel at the left side of the clock1 and thereby throw the weight a sufficient distance from the pendulum in the simplest manner4 ,the escapement we assume to be the old dead beat1 as for timekeeping it is equal to a gravity escapement while possessing advantages undesirable to sacrifice for a doubtful improvement4 ,the advantages it possesses over any form of gravity escapement are3 it has fewer pieces and not so many wheels2 it takes very much less power to drive2 is not liable to fail in action while winding1 if the maintaining power should be rather weak2 while for counting1 seconds and estimating fractions1 its clear1 definite1 and equable beat has great superiority over the complication of noises made by a gravity escapement4 ,full directions for making this and other escapements have already been given1 but in a regulator there are some considerations which will not be encountered in connection with the escapements of ordinary clocks1 where fine timekeeping is not expected4 ,we have previously stated that the center of suspension of the pendulum should be exactly in line with the axis of the escapement and we will now endeavor to state plainly how important this is in a fine clock and the reasons for it4 ,mr4 ,charles ,frodsham1 the noted ,english chronometer maker1 has conducted a series of careful experiments and the results were communicated in a report to the ,british ,horological ,society1 as follows3 ,when we talk of detached escapements1 or any escapement applied to a pendulum1 it is necessary to bear in mind that there is always one-third at the least of the pendulum's vibration during which the arc of escapement is intimately mixed up with the vibration1 either in locking1 unlocking1 or in giving impulse2 therefore1 whatever inherent faults any escapement may possess are constantly mixed up in the result2 the words 8detached escapement0 can hardly be applied when the entire arc of vibration is only two degrees2 or1 in other words1 what part of the vibration is left without the influence of the escapement8--at most one degree4 ,in chronometers the arc of vibration is from ten to fifteen times greater than the arc of escapement4 ,the dead-beat escapement has been accused of interfering with the natural isochronism of the pendulum by its extreme friction on the circular rests1 crutch1 and difficulty of unlocking1 etc41 all of which we shall show is only so when improperly made4 ,when the dead-beat escapement has been mathematically constructed1 and is strictly correct in all its bearings1 its vibrations are found to be isochronous for arcs of different extent from #j4ge of a degree to #b4ej degrees2 injurious friction does not then exist2 the run up on the locking has no influence1 nor is there any friction at the crutch2 oil is not absolutely necessary1 except at the pivots2 and there is no unlocking resistance nor any inclination to repel or attract the wheel at its lockings4 ,the general mode of making this escapement is very defective and indefinite1 and entirely destroys the naturally isochronous vibration of the pendulum4 ,the following is the usual rate of the same pendulum's performance in the different arcs of vibration with an escapement as generally constructed after empirical rules3 ,arc of vibration #c rate per diem #i4j seconds4 ,arc of vibration #b rate per diem #f4j seconds4 ,arc of vibration #b rate per diem #c4e seconds4 ,arc of vibration #a rate per diem #a4e seconds4 ,arc of vibration #a rate per diem #j4j seconds4 ,thus for a change of vibration of #a1 we have a daily error of #c4e4 ,no change of suspending spring will alter inherent mechanical errors destructive of the laws of motion4 ,with clocks made in the usual manner1 whether you apply a long or short spring1 strong or weak1 broad or narrow1 you will not remove one fraction of the error2 so the sooner the fallacy of relying upon the suspending spring to cure mechanical errors is exploded the better4 ,that the suspending spring plays a most important part must be admitted1 since1 when suspended by a spring1 a pendulum is kept in motion by a few grains only1 whereas1 if supported on ordinary pivots1 #bjj lbs4 weight would not drive it #b beyond its arc of escapement1 so great would be the friction at the point of suspension4 ,the conditions on which alone the vibrations of the pendulum will be isochronous are the following3 #a4 ,that the pendulum be at time with and without the clock1 in which state it is isochronous 8suspended by a spring40 #b4 ,that the crutch and pallets shall each travel at the same precise angular velocity as the pendulum1 which can only happen when the arc each is to describe is in direct proportion to its distance from the center of motion1 that is1 from the pallet axis4 #c4 ,that the angular force communicated by the crutch to the pendulum shall be equal on both sides of the quiescent point2 or1 in other words1 that the lead of each pallet shall be of the same precise amount4 #d4 ,that any number of degrees marked by the crutch or pallets shall correspond with the same number of degrees shown by the lead of the pendulum1 as marked by the index on the degree plate4 #e4 ,that the various vibrations of the pendulum be driven by a motive weight in strict accordance with the theoretical law2 that is1 if a #e-lb4 weight cause the pendulum to double its arc of escapement of #a1 and consequently drive it #b1 all the intermediate arcs of vibration shall in practice accord with the theory of increasing or diminishing their arcs in the ratio of the square roots of the motive weight4 ,to accomplish the foregoing conditions1 there is but one fixed point or line of distance between the axis of the escape wheel and that of the pallet1 and that depends upon the number of teeth embraced by the pallets and only one point in which the pallet axis can be placed from which the several lines of the escapement can be correctly traced and properly constructed with equal angles1 and equal rectangular lockings on both sides1 so that each part travels with the same degree of angular velocity1 which are the three essential points of the escapement4 ,much difference of opinion has been expressed upon the construction of the pallets1 as to whether the lockings or circular rests should be at equal distances from the pallet axis1 with arms and impulse planes of unequal length1 or at unequal distances from the pallet axis1 with arms and impulse planes of equal length4 ,in the latter case the locking on one side is three degrees above1 and on the other three degrees below the rectangle1 whereas in the former the tooth on both sides reposes at right angles to the line of pressure2 but the length of the impulse planes is unequal4 ,when an escapement is correctly made upon either plan1 the results are very similar4 ,it is possible to obtain equal angles by a false center of motion or pallet axis2 but then the arcs of repose will not be equal4 ,this1 however1 is not of so much consequence as that of having destroyed the conditions ,nos4 #b1 #c1 #d2 for even at correct centers1 if the angles are not drawn off correctly by the protractor1 and precisely equal to each other1 the isochronous vibrations of the pendulum will be destroyed1 and unequal arcs will no longer be performed in equal times2 the quiescent point is not the center of the vibration1 except when the driving forces are equal on both sides of the natural quiescent point of the pendulum at rest4 ,now this is the very pith of the subject1 and which few would be inclined to look for with any hope of finding in it the solution of this important question1 the isochronism of the pendulum4 ,one would naturally suppose that unequal arcs on the two sides of the vertical lines would not seriously affect the rate of the clock1 but would be equal and contrary1 and consequently a balance of errors1 and so they probably are for the same fixed vibration1 but not for any other2 because different angles are driven with different velocities1 the short angle has a quicker rate of motion than the long4 ,five pounds motive weight will multiply three times the pendulum's vibration over an arc of escapement of #j4ge2 but the same pendulum1 with an arc of escapement of #a1 would require #aa4bj lbs4 to treble its vibration2 the times of the vibration vary in the same ratio as the sum of the squares of the differences of the angles of each pallet1 compared with the spaces passed over4 ,from this it will be seen that the exact bending point of the pendulum spring should be opposite the axis of the fork arbor when regulating the clock and this may have to be determined by trial1 raising or lowering the plates by screws in the arms of the suspending brackets until the proper position is found1 when the movement may be clamped firmly in position by the binding screws1 see ,fig4 #aeh4 ,on common clocks the crutch is simply riveted on its collet and bent as required to set the clock in beat1 but for a first-class clock a more refined arrangement is usually adopted4 ,there are other plans1 but perhaps none so thoroughly sound and convenient as the following4 ,the crutch itself is made of a piece of flat steel cut away so as to leave a round boss at the bottom for the fork1 and a round boss at the top to fit on a collet on the pallet arbor1 a part projecting above to be embraced between a pair of opposing screws4 ,on the collet is fixed a thin brass plate with two lugs projecting backwards from the frame1 these lugs being drilled and tapped to receive the opposing screws in a line4 ,the boss of the crutch lies flat against this plate1 and is held up to it by a removable collet4 ,the collet may be pinned across or fitted keyhole fashion1 in either case so as to hold the crutch firmly1 allowing it to move with a little stiffness under the influence of the screws4 ,with this arrangement the adjustment to beat may be made with the utmost delicacy by slacking one screw and advancing the other1 taking care that in the end they are well set home so as to make the crutch practically all one piece with the arbor4 ,milled heads are most convenient for these screws1 and being placed at the top they are easily got at4 ,the crutch should always be fitted with a fork to embrace the pendulum rod1 as this ensures the impulse being given directly through the center1 and with the same object the acting sides of the fork should be truly square to the frame4 ,a slot in the pendulum rod with a pin acting in it is never so sure of being correct1 as1 although the surfaces may be rounded1 it is very unlikely that the points of contact will be truly in the plane of the axis of the rod4 ,the slightest error in this respect will tend to cause wobbling of the bob1 although1 to avoid this1 great attention must also be given to the suspension spring1 the pin on which it hangs1 and the pin and the hole at the top of the pendulum rod4 ,all these points must be in a true line1 and the spring symmetrical on both sides of the line in order that the impulse may be given exactly opposite the center of the mass1 otherwise wobbling must occur1 although perhaps of an amount so small as to be difficult of detection1 and this is not a matter of small importance1 as it has an effect on the rate which could be mathematically demonstrated4 ,the frames of many regulators are made too large and heavy4 ,in some cases there may be good reasons for making them large and heavy1 but in most instances1 and especially when the pendulum is not suspended from the movement1 it would be much better to make the frames lighter than we frequently find them4 ,very large frames present a massive appearance1 and convey an idea of strength altogether out of proportion to the work a regulator is required to perform4 ,they are more difficult and more expensive to make than lighter ones1 and after they are made they are more troublesome to handle1 and the pivots of the pinions are in greater danger of being broken when the clock is being put together than when they are moderately light4 ,in a clock such as we have under consideration1 where the frame is not to be used as a support for the pendulum1 but simply to contain the various parts which constitute the movement1 the thickness of the frames may with propriety be determined on the basis of the diameter of the majority of the pivots which work into the holes of the frames4 ,the length of the bearing surface of a pivot will1 according to circumstances1 vary from one to two and a half times the diameter of the pivot4 ,the majority of the pivots of our regulator will not be more than 4#je or 4#jf of an inch in diameter2 consequently a frame #j4ae of an inch thick will allow a sufficient length of bearing for the greater portion of the pivots1 and will also allow for countersinks to be made for the purpose of holding the oil4 ,if thin plates are used one or two of the larger pivots should be run in bushes placed in the frame1 as described in ,fig4 #aee4 ,the length and breadth of the frame1 and also its shape1 should be determined solely on the basis of utility4 ,there can be no better shape for the purpose of a regulator than a plain oblong1 without any attempt whatever at ornament4 ,for our regulator a frame nine inches long and seven inches broad will allow ample accommodation for everything1 as may be seen on referring to ,fig4 #aeg4 ,illustration3 ,fig4 #aed4 ,the plates are made of various alloys3 cast-brass1 nickel-silver1 and hard-rolled sheet brass4 ,it is difficult to make plates of cast-brass which would be even1 free from specks1 etc41 but cast plates may very well be made of ornamental patterns and bushings of brass rod inserted1 or they may be jeweled as shown in ,figs4 #aed1 #aee1 #aef4 ,nickel1 or ,german silver1 makes a fine plate1 but it is difficult to drill the small holes through plates of four-tenths of an inch in thickness1 on account of the peculiar toughness of the metal1 so that bushings are necessary4 ,the best material where the holes are to be in the plates is fine1 hard-rolled sheet brass2 it should have about #d oz4 of lead to the #ajj lbs41 which will make it 8chip free10 as clockmakers term it1 rendering it easy to drill2 the metal is so fine and condensed to that extent by rolling1 that the holes can be made with the greatest degree of perfection4 ,the many improvements in tools and machinery have effected great changes and improvements in clock-making4 ,it once was quite a difficult task to drill the small holes in the plates with the ordinary drills and lathes2 now we lay the plates after they are soldered together at the edges 7which is preferable to pinning71 on the table of an upright drill1 and with one of the modern twist-drills the task is rendered a very easy one4 ,after the pivot holes are drilled1 we run through from each side a round broach1 finished lengthwise and hardened1 which acts as a fine reamer1 straightening and polishing the holes exquisitely4 ,a little oil should be used on the reamer to prevent sticking4 ,the method of fitting up the pivot holes invented by ,le,roy1 a ,french clockmaker of some note1 is shown in ,fig4 #aed4 ,it is a sectional view of the plate at the pivot hole4 ,it will be observed that1 instead of countersinking for the oil1 the reverse is the case4 ,a is a hardened steel plate counterbored into the clock plate ,b1 and held in its place by the screws4 ,there should be a small space between the steel plate and the crown of the arch for the oil4 ,after the clock has been put together it is laid down on its face or side1 a drop of oil is put to the pivot end1 and the steel plate immediately put on2 and the oil will at once assume the shape of the shaded spot in the drawing1 being held in the position at the center of the pivot by capillary attraction1 until it is exhausted by the pivots2 the steel plates also govern the end play of the pinions4 ,the pivot ends being allowed to touch the plates occasionally1 the shoulders of the pinions are turned away into a curve1 and1 of course1 do not bear against the plate1 as in most clocks4 ,illustration3 ,fig4 #aee4 ,glass plates may be used instead of steel1 or rose cut thin garnets1 or sapphires1 with the flat sides smoothly polished1 may be bought of material dealers and set in bezels like a cap jewel4 ,they are very hard and smooth for the pivot ends1 and the state of the oil at the pivots can be seen at any time4 ,clocks fitted up in this manner have been running many years without oiling4 ,illustration3 ,fig4 #aef4 ,when fitted up in this way the plates may be thicker4 ,we have made the clock plates about four-tenths of an inch in thickness1 which allows of counterboring1 and admits of long bearings for the barrel arbor1 which are so liable to be worn down in the holes by the weights2 and the pivots of the pinions1 by being a little longer1 do not materially increase the friction4 ,in first-class clocks1 when all the materials are as hard as possible1 the wheels and pinions high numbered1 the teeth1 pinions1 pivots1 and holes smooth1 true1 and well polished1 the amount of wear is very slight1 especially if the driving weight has no useless excess4 ,yet there are advantages in having some parts jeweled1 such as the pallets and the four escapement holes4 ,the cost of such jeweling is not an objection1 while the diminished friction of the smooth1 hard surfaces is worth the extra outlay4 ,the holes can be set in the bushes described in ,fig4 #aef1 the end stones being cheap semi-precious stones1 either rose cut or round4 ,for jeweling the pallets1 dovetailed slots may be made so that the stones will be of a wedge shape2 there is no need for cutting the slots right through as in lever watch pallets4 ,the stones will be held more firmly if shaped as wedges lying on a bed of the steel and exposing only the circular resting curve and the driving face4 ,the slots can be filed out and the stones ground on a copper lap to fit1 fixed with shellac and pressed firmly home while warm4 ,the grinding and polishing of the acting surfaces are done exactly as described for hard steel1 only using diamond powder instead of emery4 ,the best stones are pale milky sapphires1 such as are useless as gems1 this kind of stone being the hardest4 ,the holes may be much shorter when jeweled1 as the amount of bearing surface required with stones is less than with brass2 this results in less adhesion through the oil1 and less variation of force through its changes of consistency4 ,the 'scape wheel may also be thinner with similar results1 and less weight to be moved besides4 ,so the advantages of jeweling are worth consideration4 ,it is important to finish the wheels and pinions before drilling any holes in the plates and then to definitely locate the holes after trial in the depthing tool4 ,for the clockmaker's use the next in value to the wheel cutting engine is a strong and rigid depthing tool1 for it is by means of this instrument that the proper center distances of wheels and pinions can be ascertained1 and all errors in sizes of wheels and pinions1 and shapes of teeth1 are at once detected before the holes are drilled in the plates4 ,in fact1 this tool becomes for the moment the clock itself2 and if the workman will consider that as the wheels and pinions perform in the tool for the little time he is testing them1 so they will continue to run during the life of the clock1 he will not be too hasty in allowing wheels to go as correct when a hundredth of an inch larger or smaller1 and another test1 would1 perhaps1 make the pitching perfect4 ,there are various kinds of depthing tools in use1 but many of them are objectionable for the reason that the centers are so long that the marking points on their outer ends1 are too far from the point where the pitching or depthing is being tested1 and the slightest error in the parallelism of these centers is1 of course1 multiplied by the distance1 so that it may be a serious difference4 ,having experienced some trouble from this cause1 we made an instrument with very short centers1 on the principle that the marking points1 or centers1 should be as near the testing place as possible4 ,we succeeded in making one with a difference of only three-fourths of an inch1 which was so exact that we had no further trouble4 ,it was made on the ,sector plan1 but upright1 so that the work under inspection1 whether wheels and pinions1 or escapements1 could be observed closely1 and with a glass1 if necessary4 ,it is very important that the posts or pillars and side-plates of clocks should be made and put together in the most thorough manner2 the posts should be turned exact to length and have large shoulders1 turned true1 so that the plates1 when put together without screws should fit accurately1 for if they do not1 when the screws are driven1 some of the pivots will be cramped4 ,we prefer iron for the posts1 it being stiffer1 and better retaining the screw threads in the ends1 which in brass are liable to strip unless long and deep holes are tapped4 ,steel pillars should be blued after being finely finished1 thus presenting a pleasing contrast4 ,the plate screws should also be of steel1 with large flat heads1 turned up true1 and having a washer next to the plate4 ,brass pillars are favored by many and are easier turned in a small lathe1 but they should be much larger than the steel ones4 ,illustration3 ,fig4 #aeg4 ,illustration3 ,fig4 #aeh4 ,illustration3 ,fig4 #aei4 ,when the pillars are made of brass round rod of proper diameter is the best stock4 ,if this cannot be procured1 a pattern is turned from wood1 and a little larger in every respect than the pillar is desired to be4 ,if there is to be any ornament put on the pillar1 it is never made on the pattern1 because it makes it more difficult to cast1 and besides1 the ornamentation would all be spoiled in the hammering4 ,the pattern must be turned smooth1 and the finer it is the better will be the casting4 ,after the casting is received the first thing to be done is to hammer the brass1 and then center the holes1 because it will be seen from ,fig4 #aei that there are holes for screws at each end of the pillar4 ,holes of about 4#bj of an inch are then bored in the ends of the pillars1 and should be deep1 because deep holes do no harm and greatly facilitate the tapping for the screws4 ,after the holes are tapped1 run in a bottoming tap and then countersink them a little1 to prevent the pillar from going out of truth in the turning4 ,it will depend a great deal on the conveniences which belong to the lathe the pillars are turned in as to how they will be held in the lathe and turned4 ,if the holes in the ends of the pillars have been bored and tapped true1 and if the lathe has no kind of a chuck or face plate with dogs1 suitable for holding rods1 the best way is to catch a piece of stout steel wire in the chuck and turn it true1 cut a true screw on it1 and on this screw one end of the pillar1 and run the other end in a male center4 ,however1 if the screws are not all perfectly true1 and the centers of the lathe not perfectly in line1 this plan will not work well1 and it will be necessary to catch a carrier on to the pillar and turn it between two male centers4 ,the dial feet are precisely the same as the pillars1 only smaller4 ,these dial feet are intended to be fastened in the frame by a screw1 the same as the pillars2 but it will be observed that the screw which is intended to hold the dial on the pillar is smaller4 ,the dial feet will be turned in precisely the same manner as the pillars4 ,for finishing the plain surfaces of the pillars and dial feet1 an old #f or #g-;inch smooth file makes a good tool4 ,the end of the file is ground flat1 square or slightly rounded1 and perfectly smooth4 ,the smoother the cutting surface the smoother the work done by it will be4 ,it is difficult to convey the idea to the inexperienced how to use this tool successfully4 ,in the first place1 a good lathe is necessary1 or at least one that allows the work to run free without any shake4 ,in the second place1 the tool must be ground perfectly square1 that is1 it is not to be ground at an angle like an ordinary cutting tool4 ,then the rest of the lathe must be smooth on the top1 and the operator must have confidence in himself1 because if he thinks that he cannot turn perfectly smooth1 it will be a long time before he is able to do it4 ,a tool for turning the rounded part of the pillar1 if a pattern of this style is decided on1 is made by boring a hole1 the size of the desired curve1 in an old file1 or in a piece of flat steel1 and smoothing the hole with a broach and then filing away the steel4 ,the shoulders should be smooth and flat1 or a very little undercut1 and the ends of the pillars should be rounded as is shown in ,fig4 #aei1 because rounded points assist greatly in making the frames go on to the pillars sure and easy1 and greatly lessen the danger of breaking a pivot when the clock is being put together4 ,when a washer is used the points of the pillars project half the thickness of the washer through the frames1 the hole in the washer being large enough to go on to the points of the pillars4 ,illustration3 ,fig4 #afj4 ,figure #afj is an outline of the cock required for the pallet arbor1 and the only cock that will be required for the regulator4 ,it is customary1 in some instances1 to use a cock for the scape wheel and also for the hour wheel arbors1 but for the scape wheel arbor ,i consider that a cock should never be used when it can be avoided4 ,the idea of using a cock for the scape wheel arbor is to bring the shoulder of the pivot near to the dial and thereby make the small pivot that carries the seconds hand so much shorter2 and so far this is good1 but then the distance between the shoulders of the arbor being greater1 when a cock is used the arbor is more liable to spring and cause the scape wheel to impart an irregular force to the pendulum through the pallets4 ,this is the reason why ,i prefer not to use a cock except when the design of the case is such that long dial feet are necessary1 and renders the use of a cock indispensable4 ,in the present instance1 however1 the dial feet are no longer than is just necessary to allow for a winding square on the barrel arbor1 and therefore a cock for the scape wheel is superfluous4 ,it is better to use a long light socket for the seconds hand than put a cock on the scape wheel arbor in ordinary cases4 ,except for the purpose of uniformity a cock on the hour wheel is always superfluous1 although its presence is comparatively harmless4 ,the front pivot of the hour wheel axis can always be left thick and strong enough should the design of the case require the dial feet to be extra long4 ,for the pallet arbor1 however1 a cock is always necessary1 and it should always be made high enough to allow the back fork to be brought as near to the pendulum as possible1 so as to prevent any possibility of its twisting when the power is being communicated from the pallets to the pendulum4 ,this cock should be made about the same thickness as the frames1 and about half an inch broad4 ,make the pattern out of a piece of hard wood1 either in one solid piece or by fastening a number of pieces together4 ,the pattern should be made a little heavier than the cock is required to be when finished1 and it should also be made slightly bevelled to allow it to be easily drawn from the sand when preparing the mould for casting4 ,after it is cast the brass should be hammered carefully1 and then filed square1 flat1 and smooth4 ,screws are better and cheaper when purchased1 but they may be made of steel or brass rod by any workman who is provided with a set of fine taps and dies4 ,if purchased they should be hardened1 polished and blued before using them in the regulator4 ,the threads of screws vary in proportion to the size of the screw and the material from which it is made4 ,a screw with from #cb to #dj turns to the inch1 and a thread of the same shape as the fine dies for sale in the tool shops make1 is well adapted for the large screws in a regulator4 ,however1 it is not threads of the screws ,i desire to call attention to so much1 although it must be admitted that the threads are of primary importance4 ,it is the shape of the heads and the points which is too often neglected4 ,a thread1 or a thread and a half1 cut down on the point of a screw1 will allow it to enter easier than when the point is flat1 round1 or shaped like a center4 ,this is not a new idea for making the points of screws1 but the plan is either not known to many1 or it is not practiced to the extent it ought to be4 ,the shape of the head of a screw should also always be based on utility1 and the shape that will admit of a slit into it that will wear well should be selected4 ,a round head ought never to be used1 because a head of this shape does not present the same amount of surface to the screwdriver that a square head does4 ,it is the extreme end of the slit that is most effective1 and in round-headed screws this part is cut away and the value of the head for wearing by the use of the screwdriver is the same as if the head of the screw was so much smaller4 ,a chamfered head may suit the tastes of some people better than a perfectly flat head1 but in a head of this shape the slit must be cut deeper than in a square head1 because the chamfered part of the head is of little or no use for the screwdriver to act against4 ,the slits should always be cut carefully in the center of the head and the sides of the slit filed perfectly flat with a thin file and the slight burr filed off the edge to prevent the top of the head getting bruised by the action of the screwdriver4 ,the shape of the slit which is best adapted for wearing is one slightly tapered1 with a round bottom4 ,the round bottom gives greater strength to the head1 and prevents the heads of small screws from splitting4 ,i have dwelt at some length on these little details because a proper attention to them goes a long way in the making of a clock in a workmanlike manner1 and it is desirable that the practical details should be as minute as possible4 ,the construction of the barrel is a subject which requires a greater amount of consideration than is sometimes bestowed upon it4 ,we often meet with regulator barrels which have considerable more brass put into them than is necessary4 ,the value of this extra metal is of little or no consequence4 ,it is the unnecessary pressure the weight of it causes on the barrel pivots1 and the consequent increase of friction1 which is objectionable4 ,for this reason the weight of the barrel1 as well as the weight of every other part of the clock that moves on pivots1 should be made no heavier than is absolutely necessary to secure the required amount of strength4 ,in every instance1 except when the diameter is required to be very small1 the barrel should be made of a piece of thin brass tubing with two ends of cast-brass fastened into it4 ,illustration3 ,fig4 #afa4 ,figure #afa is a sectional view of the ends of a barrel2 the diagram on the right is the end where the great wheels rest against1 and the one on the left is the other end4 ,the insides of both these ends are precisely the same1 but the outsides differ a little4 ,it will be observed that there is a little projection near the hole on the outside of the front end4 ,this projection is left with the view of making the hole in the center longer1 and thereby causing this end to take a firmer hold on the barrel arbor4 ,the back end1 or the end that the great wheels rest against1 and where the ratchet teeth are cut1 is shaped precisely like the diagram on the right of ,fig4 #afa4 ,if you cannot get brass plate of sufficient thickness for the ends of the barrel they must be cast4 ,the patterns for these barrel ends should be made without any hole in the center1 and in every way heavier and thicker than they are to be when finished1 because it is difficult to obtain good and solid castings when the patterns are made thin1 although it is by no means impossible to make them so4 ,like all brass castings used for the clockmaker's purpose1 they should be carefully hammered1 and1 although these pieces are of an irregular shape1 they can be easily hammered regularly with the aid of narrow-faced hammers or punches1 and with the exercise of a little patience4 ,after hammering1 the castings should be placed on a face plate in the lathe1 and the tube which is to form the top part of the barrel fitted easy and without shake on to the flanges and the other parts of the castings turned down to the required thickness1 and a hole a little less than #j4c of an inch diameter bored in the center of each before it is removed from the face plate4 ,the tube which is to form the top of the barrel should be no heavier than is just necessary to cut a groove for the cord1 and for this regulator it should be #a4e inch diameter outside measurement1 #a4e inch long1 and turned perfectly true on the ends4 ,the hole in the front end of the barrel1 which is the end nearest to the dial1 should be broached a little from the inside1 and the other end broached a little larger from the outside4 ,the reason for broaching the holes in this manner is to cause the thickest part of the barrel arbor to be at the place where the great wheels work1 because1 in making a barrel for a regulator1 it will generally be found that the arbor requires to be thickest in this particular place4 ,the arbor should be made from a piece of fine cast steel a little more than #j4c of an inch thick1 and not less than four inches long4 ,it is always well to have the steel long enough4 ,this steel should be carefully centered and turned true1 and of the same size and taper as the holes in the barrel ends4 ,it is not necessary that the barrel arbor should be hardened and tempered1 except on special occasions4 ,in most cases it will last as long as any other part of the clock if it is left soft1 and it is much easier to make when soft4 ,before fitting the arbor to the barrel ends it is well to place the ends into the tube that is to form the top of the barrel1 because a better fit can be made in this way than when each is fitted separately4 ,when the arbor has been fitted1 a good and convenient way of fastening it together is1 to use soft solder4 ,it can be easily heated to the required degree of heat with the blow-pipe4 ,a very little solder is sufficient for the purpose1 and if the joints have been well fitted the solder will not show when the work is finished4 ,care should be taken to notice that the solder adheres to the arbors properly4 ,perhaps it would be well to mention here that1 should the clockmaker not have access to a cutting engine with conveniences attached to it for cutting the barrel ratchet after the barrel has been put together1 the ratchet should be cut first4 ,when the different pieces which constitute a barrel have been fastened together the brass work has next to be turned true1 and the grooves cut for the cord to run in4 ,it is best not to turn anything off the arbor till the grooves are cut1 because they are usually cut smoother when the arbor is strong4 ,the most important points to notice when turning a barrel is to be sure that the top is of equal diameter from the one end to the other1 and that the bearing where the great wheels rest against are perfectly true1 because1 if the top of a barrel is of unequal thickness1 the weight will pull with unequal force as it runs down1 and if the bearing on the end be out of truth the great wheels will also be very liable to get out of truth1 as their position on the barrel is altered by winding the clock up4 ,the shape of the outside of the barrel ends1 as is represented in ,fig4 #afa1 will be found to be good and serviceable4 ,,aa is the bearing for the great wheels to rest against2 ,,bb is where the ratchet teeth are to be cut4 ,there must be a little turned off the face of ,,bb1 as is shown in the diagram1 so as to prevent the great wheel from rubbing on the teeth4 ,the space between ,,aa and the barrel arbor is turned smooth4 ,although it is by no means an absolute necessity to have a groove cut in the top of the barrel1 yet it is extremely desirable that there should be one1 so that the cord may always be guided with certainty as the clock is wound up4 ,it has long been a disputed question whether the cord should be fastened at the front end of the barrel and wind towards the back1 or whether it should be fastened at the back and wind towards the front4 ,i am not aware that there is any violation of principle1 so far as the regularity of the power is concerned1 whether the cord runs one way or the other4 ,i understand it to be solely a question of keeping the weight clear of the case and the pendulum ball4 ,in ordinary constructed regulator cases this object will be best attained by cutting the screw so that the cord can be fastened at the front of the barrel and wind towards the back2 because in making it in this way1 the weight is the length of the barrel farther away from the front of the case when it is wound up1 and about the same distance farther away from the pendulum ball when it is nearly run down1 than if the cord was fastened at the back end of the barrel and wound towards the front4 ,the cutting of the groove is usually done in an ordinary screw cutting lathe4 ,in making the pivots on a barrel it is the usual custom to make the back pivot smaller than the front one but1 with all due respect for this time-honored custom1 ,i would direct a little attention to the philosophy of continuing to make the barrel pivots of a regulator in this manner4 ,friction varies with pressure2 a large pivot has a greater amount of friction than a smaller one1 because the pressure on the sliding surface of the revolving body is farther away from the center of motion in one case than in the other4 ,in regulators where the barrel pivots are of a different size1 the effective force of the weight will vary slightly according as the weight is fully wound up or nearly run down4 ,in one instance the pressure of the weight is more directly on the large pivot than it is on the smaller one2 and in the other instance the pressure is more directly on the small pivot than it is on the larger one1 and when the weight is half wound up1 or half run down1 the pressure is equal on both pivots4 ,in the center pinion and in some of the other arbors of a clock1 it is sometimes necessary to make one pivot considerably larger than the other2 but in these cases the difference in the size of the pivots does not affect the regularity of the transmission of the power1 because the pressure that turns the wheel is always at the same point4 ,in a regulator barrel1 however1 the pressure of the cord and weight shifts gradually from one end of the barrel to the other1 as the clock runs down1 and when the pivots are of unequal thickness the power is transmitted nearly as irregular as if the top of the barrel was slightly conical and both pivots of the same size4 ,for the above reason1 ,i think1 that it will be plain to all that in a fine clock both of the barrel pivots should be made of an equal diameter4 ,the front pivot should be made no larger than is absolutely necessary for a winding square1 and when we take the fact into consideration that a fine clock with a ,graham escapement requires considerable less power to keep it in motion than an eight-day marine chronometer does1 we may safely conclude that the winding squares of many regulators of the ,graham class might be made smaller4 ,a pivot about #j4b of an inch will secure a sufficient amount of strength4 ,for the reasons mentioned above1 the back pivot should be exactly the same diameter1 and although the effects of friction will be slightly greater when both pivots are of an equal size1 still the force of the weight will be transmitted more regularly1 which is the object aimed at4 ,where the plates are bushed a length of two to three diameters is long enough for the pivot holes4 ,the stop works1 maintaining powers and general arrangement of the great wheel1 ratchets and clicks1 have been so fully described and illustrated on pages #bhb to #bij1 ,figs4 #hc to #hg1 that it would be useless duplication to repeat them here1 and the reader is therefore referred to those pages1 for full particulars4 ,this is also the case with the purely mechanical operations of cutting the wheels and pinions1 hardening1 polishing1 staking1 etc42 all have been fully treated2 but there are some further considerations which may be mentioned here4 ,the practical value of making pinions with very high numbers is very much over-rated4 ,i know of two clocks situated in the same building that are compared every other day by transit observation4 ,they both have ,graham escapements and mercurial pendulums1 and are equally well fitted up1 and as far as the eye can detect1 they are about equally well made in all the essential points1 with only this difference3 one clock has pinions of eight1 and the other pinions of sixteen leaves1 yet for two years one clock ran about equally as well as the other4 ,in fact1 if there was any difference1 it was in favor of the clock with the eight-leaved pinions4 ,in giving this example1 ,i must not be understood to be placing little value on high numbered pinions4 ,i know that in some instances they can be used to advantage4 ,the idea that ,i want to illustrate at present is1 that it is not in this direction that we are to search for the means of improving the rates of regulators4 ,a pinion as low as eleven leaves can be made so that the action of the tooth will begin at or beyond the line of centers2 but as eleven is an inconvenient number to use in clockwork1 we may with great propriety decide upon twelve as being a sufficient number of leaves for all the pinions used in a regulator having a ,graham escapement4 ,in arranging the size of the wheels in a regulator1 the diameters of the center and third wheels are determined by the distance between the center of the minute and the center of the seconds hand circle on the dial4 ,as the dials of regulators are usually engraved after the dial plates have been fitted1 and as the position of the holes in the dial for the center and scape wheel pivots to come through determines the size of the seconds circle1 it may be well to mention here that1 for a twelve-inch dial1 two and a half inches is a good distance for the center of the minute circle to be from the center of the seconds circle4 ,consequently the center and third wheels must be made of such a diameter as will raise the scape wheel arbor two and a half inches from the center arbor1 and the other wheels must be made proportionally larger1 according to the number of teeth they contain4 ,we all know what a difficult matter it is to make a cutter that will cut a tooth of the proper shape2 but when the cutter is once made and carefully used1 we also know that it will cut or finish a great number of wheels without injury4 ,for this reason1 those who are contemplating making only one1 or at most but a few regulators1 will find the work will be greatly simplified by making the wheels of a diameter proportionate to the number of teeth they contain1 and for all practical purposes the cutter that cuts or finishes the teeth of one wheel will be sufficiently accurate for the others4 ,if we make all the pinions with the same number of leaves they will also all be nearly of the same diameter1 and may be cut1 or rather the cutting operation may without any great impropriety be finished with one cutter4 ,an opinion prevails among a certain class of workmen that the teeth of the great wheel and leaves of the center pinion should be made larger and stronger than the other wheels and pinions1 because there is a greater strain upon them than on the other4 ,however reasonable this idea may seem1 a little consideration will show that in the case of a regulator1 with a ,graham escapement1 where so little motive power is required to keep it in motion1 an arrangement of this nature is altogether unnecessary4 ,the smallest teeth ever used in any class of regulators are strong enough for the great wheel2 and if there be a greater amount of strain on the teeth of the great wheel in comparison with the teeth of the third wheel1 for example1 then make the great wheel itself proportionately thicker1 as is usually done1 according to the extra amount of strain that it is to bear4 ,the teeth of wheels and the leaves of pinions wear more from imperfect construction than from any want of a sufficient amount of metal in them4 ,if we assume the distance between the center of the minute and the center of the seconds circle to be #b inches1 and also assume that the clock will have a seconds pendulum1 and all the pinions have #ab leaves1 and the barrel make one turn in #ab hours1 then the following is the diameter the wheels will require to be1 so that the teeth may all be cut with one cutter1 and also the number of teeth for each wheel3 ,great wheel #add teeth4 ,diameter #c4dj inches for the pitch circumference4 ,hour wheel #add teeth4 ,diameter #c4dj inches for the pitch circumference4 ,center wheel #if teeth4 ,diameter #b4bf inches for the pitch circumference4 ,third wheel #ij teeth4 ,diameter #b4aa inches for the pitch circumference4 ,scape wheel #cj teeth4 ,diameter #a4ge inches for the pitch circumference4 ,the number of arms or crosses to be put in a wheel is usually decided by the taste of the person making the clock4 ,there is1 however1 another view of the subject1 which ,i would like to mention4 ,with the same weight of metal a wheel will be stronger with six arms than with four or five1 and as lightness1 combined with strength1 should be the object aimed at in making wheels1 ,i prefer six arms to four or five for the wheels of a regulator4 ,figs4 #aeg and #aeh are front and side elevations of the proposed regulator movement1 showing the size and position of the wheels1 the size of the frames1 the positions of the pillars1 dial feet1 etc4 ,the dotted large circular lines on ,fig4 #aeg show the position the hour1 minutes1 and seconds circles will occupy on the dial4 ,according to the ordinary rules of drawing1 the dotted lines would infer that the movement is in front of the dial1 and perhaps it may be necessary to explain that in the present instance these lines are made dotted solely with the view of making the diagram more distinct1 and are not intended to represent the dial to be at the back of the movement4 ,a is the barrel1 ,b is the great wheel1 which turns once in twelve hours2 ,c is the hour wheel1 which works into the great wheel1 and also turns once in twelve hours2 ,d is the center wheel1 which turns once in an hour1 and carries the minute hand2 ,e is the third wheel1 and ,f is the scape wheel1 which turns once in a minute and carries the seconds hand2 ,g is the pallets2 ,h the pillars1 and ,i is the dial feet2 ,j is the maintaining power click1 and ,k shows the position of the cord4 ,neither the hour or great wheels project over the edge of the frame1 and it will be observed that a clock of this arrangement is remarkable for its simplicity1 having only four wheels and three pinions1 with the addition of the scape wheel and the barrel ratchets4 ,there are no motion or dial wheels1 the wheel ,c turning once in #ab hours1 carrying the hour hand4 ,the size and shape of the frames and the position of the pillars1 allows the dial feet to be placed so that the screws which hold the dial will appear in symmetrical positions on the dial4 ,formerly the term 8astronomical0 was applied to clocks which indicated the motions and times of the earth1 moon1 and other celestial bodies1 but at present we may take it as indicating such as are used in astronomical observatories4 ,in all essential particulars they are the same as first-class watchmakers' regulators1 the most obvious departure being that the hour hand is made to revolve only once a day1 the dial being divided into twenty-four hours4 ,this only requires an intermediate wheel and pinion in the motion work1 and1 assuming the hour hand to be driven from the center arbor1 there will be the usual hour and minute wheels and cannon pinion4 ,the most suitable ratio for these are and _/1 and1 as any numbers1 being multiples1 may be used1 they may as well be selected so as to be cut with the same tools as the wheels of the train4 ,two pinions of #bj and wheels of #hj and #abj suit very well2 #bj #hj and #bj #abj _/ _/ _/ _/1 and the hands will both go in the same direction4 ,some astronomical clocks show mean solar1 and others sidereal time2 this requires no structural alteration1 merely a little shortening of the pendulum in the latter case1 which can be done with the regulating nut4 ,,list ,,of ,,illustrations4 ,a ,addendum1 #bjb1 #bah1 #bbj ,angular ,motion1 #ajc1 #aab ,automatic ,pinion ,cutter1 #bde1 #bdg 8 8 ,drill1 #bdi 8 ,wheel and ,pinion ,cutter1 #bed ,c ,calendar1 ,simple1 #cea 8 ,perpetual1 #ced1 #cef1 #ceh ,center ,distances1 #aje1 #aaa1 #bjb ,chimes1 ,laying out1 #cgj1 #dba1 #dbb1 #dbc1 #dbd1 #dbe ,chimes ,westminster1 #cgb ,click1 ,position of1 #bhh ,cock1 #dhb ,compensated ,rod1 ,steel and ,zinc1 #db ,counter-poising ,hands1 #ddc ,count hook1 ,position1 of1 #cje ,count ,wheel ,striking ,train1 #cjb1 #cjc1 #caa1 #cad1 #cae1 #caf1 #cbb1 #cbd ,cuckoo ,bellows and ,pipe1 #cbh ,d ,dedendum1 #bjb ,dial ,work1 #bie ,diameters of ,wheels1 ,getting1 #aif ,e ,eight-day ,count ,wheel1 ,time and ,striking ,trains1 #bii1 #cji ,eight-day ,snail ,strike1 #cdb ,electric ,chimes1 #dba1 #dbb1 #dbc1 #dbd1 #dbe ,electric ,clocks1 ,pendulum ,driven1 #cgg1 #cgi1 #cha1 #chb ,electric ,clocks1 ,weight ,driven1 #cid1 #cie1 #cif1 #cih ,epicycloid1 #bjf1 #bai1 #bci ,escape ,wheel1 ,cutting1 #abb1 #abd 8 8 ,drawing to fit ,pallets1 #abj ,escapement1 ,anchor1 #adb1 #add1 #ade1 #adf1 #adg 8 ,brocot's ,visible1 #abg1 #abi 8 ,cylinder1 #afd1 #afe1 #aff1 #afg1 #agg1 #agi1 #aha1 #ahc 8 ,dead ,beat1 #aag1 #aah 8 ,drum1 #adh 8 ,gravity1 #aeb1 #aed1 #aeg1 #aei1 #afa 8 ,pin1 #ahe1 #aid 8 ,pin ,wheel1 #acf1 #acg 8 ,recoil1 #adb1 #add1 #ade1 #adf1 #adg 8 to draw the1 #aad ,f ,friction ,springs1 #bid ,g ,grandfather clocks1 #ceb ,h ,hypocycloid1 #bjf ,k ,keyhole ,plates1 #bhi ,l ,lever ,escapement for ,clocks1 #aic ,levers1 the ,elements of1 #ii1 #ajj1 #aja ,m ,maintaining ,powers1 #bhe1 #bhf1 #bhg1 #bia ,p ,pallets1 ,drawing1 #aaf ,pendulum ,brackets1 #cb 8 ,mercurial1 #fg1 #ga1 #ge 8 ,torsion1 #ib1 #ic1 #id1 #ie 8 ,oscillation of1 #aj1 #ad1 #ba 8 ,rieffler1 #ej1 #ge ,perpetual ,calendar ,clocks1 #ced1 #cef1 #ceh 8 ,brocot1 #cfj1 #cfb1 #cfc1 #cfd1 #cff ,pinion ,drill1 #bea ,pitch ,diameter1 #bjb1 #bah1 #bai1 #bbj1 #bci ,plate1 ,jeweling1 #dge1 #dgf ,posts1 #dhj ,precision ,clock ,room1 #deb ,q ,quarter ,chiming ,snail ,trains1 #cda ,quail and ,cuckoo ,train1 #cbb1 #cbd ,r ,rack1 ,division of1 #cce ,regulator ,trains1 #dfe1 #dfg1 #dgi ,rounding-,up ,wheels1 #bbj1 #bbd ,s ,secondary ,dials1 #daf ,self ,winding ,clocks1 #djj1 #dja1 #djd1 #djf1 #djh1 #dab ,ship's ,bell ,train1 #cad1 #cae1 #caf ,slide ,gauge ,lathe1 #bda 8 8 ,tools1 #bdc ,snail1 ,laying ,out1 #ccg 8 ,striking ,trains1 #ccc1 #cdb1 #cde1 #cdf ,suspension ,springs1 #hd ,synchronizing ,clocks1 #dab1 #dae ,w ,wheel ,cutting ,engine1 #bee ,wiring ,systems1 #chf1 #chh ,wood ,rod and ,lead ,bob1 #cc ,z ,zinc ,bob and ,wood ,rod1 #cca ,,index4 ,a ,addendum1 #bjb ,air1 ,pressure of1 #bj ,aluminum1 ,compensation with1 #dh ,anchor ,escapement1 #ada ,angular ,measurement1 ,peculiarities of1 #ajb ,apparent ,time1 #cdh ,arbors1 ,polishing ,steel1 #bcb 8 ,straightening ,bent1 #bca ,arc of ,escapement1 #ic1 #aji1 #aae1 #abg1 #ach1 #ade1 #aec1 #afd1 #ahf1 #dfi ,armatures1 ,adjustment of1 #chi1 #dji ,astronomical ,clocks1 #dic 8 ,day1 #cdh ,auxiliary ,weights1 #cg ,b ,balance1 ,vibrations of1 #ahj ,banking1 #ij1 #aef1 #afj1 #agj1 #agf ,barometric ,error1 #bj ,barrels1 #bdd1 #bfg1 #dfe1 #dhe 8 ,chiming1 #cgj ,batteries1 #chj 8 ,dating1 #cib 8 ,grading1 #chd 8 ,making1 #chc 8 ,position of1 #che 8 ,wiring1 ,methods of1 #che ,beat1 to put a ,clock in1 #hi ,bells1 #cfi 8 ,ships1 #cae ,brocot's ,calendar1 #cei 8 ,visible ,escapement1 #abg1 #abh ,bushing1 #dgf ,c ,cables1 ,clock1 #bfi 8 ,lengths of1 #bga ,calculations of ,weights1 #eg ,calendars1 #cdg 8 ,brocot's1 #cei 8 ,gregorian1 #cdi 8 ,julian1 #cdi 8 ,perpetual1 #cec 8 ,simple1 #cej ,carillons1 #cgb ,case ,friction1 #ddh 8 ,temperature1 #dej ,cases1 #ddf 8 ,gilding1 #dei 8 ,marble1 #dfj 8 8 to ,polish1 #dfa 8 ,polishing1 #deg 8 ,precision ,clock1 #ddg 8 ,regulator1 #dfc 8 ,restoring old1 #dee ,cement for ,marble1 #dfj 8 for ,dials1 #dch ,center ,distances1 #aaj1 #bjj 8 of ,gravity1 #ah 8 of ,oscillation1 #ac 8 ,springs1 #if1 #bid ,chain ,drives1 #bga ,cheap ,clocks1 to clean1 #ahg ,chime ,barrels1 to mark1 #cga ,chimes1 #cci1 #cgj 8 ,cambridge1 #cgb 8 ,carillon1 #cgb 8 ,electric1 #dbj 8 ,tubular1 #cgd1 #dbb ,circle1 ,pitch1 #bjb ,circular ,error1 #ba 8 ,pitch1 #bae ,cleaning ,cheap ,clocks1 #ahg ,clocks1 ,astronomical1 #dic 8 ,cuckoo1 #cai1 #cba 8 ,designing1 #h 8 ,four-hundred day1 #ia ,clocks1 ,glass of1 #dfb 8 ,repeating1 #ccb 8 ,room1 #deb ,cock1 #dhb ,collets1 #bcd ,compensated ,pendulum ,rods1 #dj 8 ,rod1 ,flat1 #da 8 ,rods1 ,tubular1 #dh ,compensation1 #dej ,compensating ,pendulums1 #bc 8 8 ,bracket for1 #cb ,compensating ,pendulums1 ,principles of ,construction1 #bg ,compensating ,pendulums with shot1 #cf ,compensating ,pendulums1 ,wood ,rod and ,lead ,bob1 #cb ,compensation ,pendulums1 ,wood ,rod and ,zinc ,bob1 #bh ,compensation ,pendulums1 ,aluminum1 #dh ,cones1 ,rusting of1 #aij ,construction of ,dials1 #dbf ,contacts1 ,dial1 #dbc1 #dbe 8 ,electric1 #cif ,contrate ,wheel1 #aga1 #cge ,conversion1 ,table of1 #ah ,cords1 #bfh 8 ,lengths of1 #bgj ,count ,hook1 #cja1 #cjd1 #caj 8 ,wheel1 #cja1 #cjd1 #cae 8 8 ,train1 #cjj ,crown ,wheel1 #aga ,crutches1 #hg1 #dgb ,cuckoo1 ,adjustments of1 #cbf 8 ,bellows1 #cbh 8 ,clock1 ,names of ,parts1 #cbc 8 ,motion ,work1 #bif 8 ,repairing1 #cbg ,cutters for ,clock ,trains1 #aif 8 ,setting1 #aig ,cycloid1 #ba ,cylinder ,clocks1 ,examination of1 #aga ,cylinder1 ,end ,shake1 #agj 8 8 ,proportion of1 #adi 8 ,side ,shake1 #afg 8 ,teeth1 ,shape of1 #ahc ,cylinders1 ,weight of1 #cg ,d ,day1 ,astronomical1 #cdh 8 ,sidereal1 #cdh 8 ,solar1 #cdh ,dedendum1 #bjb ,dennison ,escapement1 #aej ,depolarizers1 #cha ,depthing1 #bjj 8 ,tool1 #dgg ,designing ,clocks1 #h ,detached ,lever ,escapement1 #ahd ,dials1 ,construction of1 #dbf 8 ,contacts1 #dbc1 #dbe 8 ,enamel for1 #dca 8 ,phosphorescent1 #dcg 8 ,repairing1 #dcb1 #dch 8 ,secondary1 #dag 8 to ,clean1 #dcf 8 8 ,silver1 #dcd 8 ,varnish for1 #dch ,distances1 ,center1 #bjj ,drawings1 to read1 #ih ,draw of ,teeth1 #aid ,drill1 ,pinion1 #bdi1 #bea ,drop1 #ajg ,e ,effect of ,temperature1 #fb ,eight ,day ,trains1 #bii ,electric ,chimes1 #dbj 8 ,clocks1 #cgf 8 8 ,synchronizing1 #djj1 #dac 8 ,contacts1 #cif ,elements1 ,mechanical1 #ih ,enamel for ,dials1 #dca ,end ,shake1 of ,cylinder1 #agj1 #age ,end ,stones1 #dgg ,epicycloid1 #bjf ,equation of ,time1 #cfe ,error1 ,barometric1 #bj 8 ,circular1 #ba 8 ,temperature1 #bb ,escape ,wheel1 ,sizes of1 #aji1 #acc1 #aee1 #afd 8 8 ,to make1 #aji1 #abj1 #ace1 #ach1 #aej1 #aee1 #afb1 #afd ,escapement1 ,brocot's1 #abg1 #abh 8 ,cylinder1 #afc 8 ,dennison1 #aej 8 ,detached ,lever1 #ahd 8 ,drum1 #adh 8 ,graham1 #aji 8 ,gravity1 #aej1 #afa 8 ,le ,paute's ,pin ,wheel1 #ace 8 ,pin1 #ahe1 #aic 8 ,recoil1 #ada 8 ,to draw ,graham1 #aac 8 8 ,pin ,wheel1 #ach 8 8 ,gravity1 #aeb 8 ,western ,clock ,mfg4 ,co41 #aic ,examination of ,cylinders1 #aga ,expansion of ,metals1 #bb ,f ,fan1 #cjh1 #cbf ,fly for ,gravity ,escapement1 #aeh ,frames1 ,making1 #bfa 8 ,thickness of1 #dgd ,four-hundred ,day ,clocks1 #ia ,friction1 ,disengaging1 #bjc 8 ,engaging1 #bjc 8 of ,teeth1 #acb 8 ,springs1 #bid ,g ,gathering ,pallet1 #cch1 #cdd ,gilding1 #dei ,gong ,wires1 #cfi ,graham ,escapement1 #aji1 #dfg ,gravity1 ,center of1 #ah 8 ,escapement1 #aej ,gregorian ,calendar1 #cdi ,h ,half ,hour ,striking ,work1 #ccd1 #cdb1 #cde ,hammers1 #cfg 8 ,hardening1 #aih1 #dhj1 #dhb 8 ,springs1 #cfh 8 ,tail1 #bih1 #cja ,hands1 #dci 8 ,proportions of1 #ddj 8 ,to ,balance1 #ddb 8 ,to ,blue1 #ddd ,hour ,rack1 #cce 8 ,snail1 #bif1 #ccd 8 ,strike1 #cdb 8 ,wheel1 #if1 #bic1 #bif1 #cbe ,hypocycloid ,curves1 #bjf ,i ,iron1 ,expansion of1 #eg ,information1 ,need for1 #c ,isochronism1 #dfi ,j ,jeweling1 #dge1 #dgg ,jewels1 ,pallet1 #abf ,julian ,calendar1 #cdi ,l ,lantern ,pinions1 #bce ,lathe1 ,slide ,gauge1 #bda1 #bdc1 #bdf ,laws of ,pendulums1 #aa ,lead1 #bb1 #cb ,leap ,year1 #cdi ,length of ,pivots1 #aii ,le ,paute's ,escapement1 #ace ,leverage of ,wheels1 #ii ,lift1 #ajf ,lifting ,cam1 #cja1 #cca 8 ,piece1 #cca 8 ,planes1 #aaf 8 ,pins1 #ahf ,lock1 #ajg ,locking ,hook1 #cja ,losing ,time1 #aib ,lunation1 #cfe ,m ,magnets1 ,arrangement of1 #cgh1 #chf1 #chi1 #cie1 #dja1 #djf ,mainsprings1 #bgb1 #bgd1 #bgg1 #bgh1 #bgi1 #bhj1 #bha1 #bhb 8 ,breakage of1 #bha 8 ,buckled1 #bgg 8 ,cleaning1 #bgg 8 ,clock1 #bhh 8 ,coil ,friction1 #bgg 8 ,fusee1 #bgi 8 ,importance of ,cleaning1 #bgd 8 ,length of1 #bhj 8 ,loss of ,power1 #bgd 8 ,maintaining ,power1 #bhe1 #bia 8 ,oiling1 #bgh 8 ,stop ,works1 #bhb ,maintaining ,powers1 #bhe ,mean ,apparent ,time1 #cdh ,mean ,time1 #cdh ,measuring ,wheels1 #aie ,measurement1 ,angular1 #ajb ,mechanical ,elements1 #ih ,mercurial ,pendulums1 #ec1 #fj1 #fi 8 8 ,for ,tower ,clocks1 #fe ,mercury1 #ec1 #ef1 #ff1 #gj ,metals1 ,expansion of1 #bb 8 ,weight of1 #cg ,millimeters ,compared with ,inches1 #ah ,minute ,jumpers1 #dag 8 ,wheels1 #if1 #bic1 #bif1 #cbe ,month ,clocks1 #bfj 8 ,sidereal1 #cdi 8 ,synodic1 #cej ,moon1 ,phases of1 #cfe 8 ,train1 #cfe ,motion ,work1 #if1 #bic1 #bif1 #cbe ,n ,need for ,information1 #c ,numbers1 ,conversion of1 #bja ,nut1 ,rating1 #db1 #ej1 #ff ,o ,oiling ,cables1 #bfi ,oscillation1 ,center of1 #ac ,overbanking1 #ij1 #aef1 #afj1 #agj1 #agf ,p ,pallet ,jewels1 #abf ,pallets1 #ajf1 #aae1 #aba1 #abf1 #acj1 #ace1 #aci1 #ada1 #add1 #adi1 #aec1 #ahf1 #aic1 #dgj ,pallets1 ,to make1 #aai1 #abf ,pendulum1 ,isochronous1 #dgj 8 ,lengths1 ,table of1 #aj1 #af 8 ,rieffler1 #di1 #ge 8 ,rods1 #bfb 8 8 ,compensated1 #dj 8 ,compensating1 #bc 8 ,electric ,driven1 #cgf 8 ,laws of1 #aa 8 ,mercurial1 #ec1 #fj1 #fi 8 ,sidereal1 #dic 8 ,torsion1 #ia ,perpetual ,calendar1 #cec ,phases of the ,moon1 #cfe ,pillars1 ,making1 #bdj ,pinion ,drill1 ,automatic1 #bdi1 #bea 8 ,making1 #bbg1 #beb 8 8 ,machine1 ,automatic1 #bde1 #bdg 8 ,canon1 #bic1 #bid1 #bie 8 ,depthing1 #bjf1 #baj1 #bag 8 ,facing1 #bcc 8 ,hardening1 #bbi 8 ,lantern1 #bce 8 ,tempering1 #bcj 8 ,to ,draw1 #bjf ,pin ,escapement1 #ahe1 #aic 8 ,wheels1 #big1 #cja1 #cbg 8 8 ,escapement1 #ace 8 8 8 ,to ,draw1 #ach ,pitch1 ,addendum1 #baf 8 ,circle1 #bjb 8 ,circular1 #bae 8 ,diametral1 #baf ,pivots1 #dhh 8 ,length of1 #aii 8 ,proportions of1 #afg1 #agc1 #aii1 #dgd 8 ,side ,shake1 #aii ,planes1 ,lifting1 #aaf ,plates1 ,clock1 #aih 8 ,thickness of1 #dgd ,poising ,balance ,staffs1 #ahi1 #aij ,polishing ,steel ,arbors1 #bcb ,posts1 ,clock1 #dgh ,power1 #bfd1 #bfe1 #bff1 #bfg 8 ,maintaining1 #bhe ,putting in ,beat1 #hi ,r ,rack1 ,division of1 #cce 8 ,striking ,work1 #cca ,ratchet1 #bhh ,rating ,nut1 #db1 #ej1 #ff 8 ,with ,shot1 #ij ,reading ,drawings1 #ih ,repeating ,clocks1 #ccb ,recoil ,escapement1 #ada ,regulation1 #gi ,regulator ,trains1 #dib ,regulators1 ,making1 #dfc ,repairing ,dials1 #dcb1 #dch ,resistance ,spools1 #chh ,rieffler ,pendulum1 #di1 #ge ,rounding-,up1 #agd1 #bba1 #bbc 8 8 ,rules for1 #bbf ,run1 #ajh ,rusting of ,cones1 #aij ,s ,screws1 ,clock1 #dhc ,secondary ,dials1 #dag ,self-winding ,clocks1 #cgf ,ship ,bells1 ,striking1 #cac ,shot1 ,rating with1 #ij ,sidereal ,day1 #cdh 8 ,month1 #cdi 8 ,pendulums1 #dic 8 ,year1 #cdi ,side ,shake1 ,cylinder1 #afg 8 8 ,for ,pivots1 #aii ,silvering ,dials1 #dcd ,simple ,calendar1 #cej ,sizes of ,teeth1 #baa1 #bac1 #bcg 8 8 ,wheels1 #bja ,slide ,gauge ,lathe1 #bda1 #bdc1 #bdd ,snail1 #bif1 #ccf 8 ,division of1 #ccg 8 ,french ,system1 #cdb 8 ,quarter ,striking ,work1 #cci 8 ,striking ,work1 #ccj1 #cdj ,solar ,day1 #cdh ,sparking1 to ,prevent1 #chf ,springs1 ,center1 #bid 8 ,clock1 #bgc1 #bhh1 #cjg 8 ,friction1 #bid 8 ,hammer1 #cfh 8 ,main1 #bgb1 #bgc1 #bgd1 #bgg1 #bgh1 #bgi1 #bhj1 #bhb1 #cjg ,squares1 ,milling1 #bfa ,standards1 ,importance of1 #bf ,star ,wheel1 #ccb1 #cce ,steel1 ,expansion of1 #eg ,stop ,works1 #bhb ,straightening ,bent ,arbors1 #bca ,striking from ,center ,arbor1 #bih 8 ,to ,correct1 #cjf1 #cjg 8 ,trains1 #big1 #cjh1 #cac1 #cbc1 #ccj 8 8 ,half ,hour1 #bih1 #cjh1 #cac 8 8 ,setting ,up1 #cjg1 #caj1 #cci 8 8 ,to ,calculate1 #big 8 8 ,rack1 #cca 8 ,work1 ,repeating1 #ccb 8 8 ,snail1 #ccj1 #cdj ,supports1 ,pendulum1 #hf ,suspension1 #ha1 #ic 8 ,springs1 #hb1 #ic ,synchronizing1 #djj1 #dac ,synodic ,month1 #cej ,t ,table1 ,lengths of ,pendulum1 #ab1 #af1 #ag1 #cd1 #beh 8 of ,expansions1 #cj 8 ,inches1 ,millimeters and ,french ,lines1 #ah 8 8 ,time ,trains1 #beh1 #cci1 #cdj1 #dib 8 8 ,weights and ,metals1 #cg ,tangent1 #ajd ,teeth1 ,friction of1 #acb 8 ,shape of ,cylinder1 #ahc 8 ,shapes of1 #bjc 8 ,sizes of1 #baa1 #bac1 #bcg ,temperature1 ,effect of1 #fb 8 ,error1 #bb ,tempering1 #bbi ,time1 ,apparent1 #cdh 8 ,equation of1 #cfe 8 ,losing1 #aib 8 ,mean1 #cdh ,to ,draw ,anchor ,escapement1 #adc1 #ade1 #adg ,top ,weights1 #ci ,torsion ,pendulums1 #ia ,tower ,clock1 ,cables1 #bfi 8 8 ,dials1 ,sizes of1 #dbf 8 8 ,gravity ,escapement for1 #aej 8 8 ,hands1 #ddb 8 8 ,maintaining ,powers1 #bhe1 #bia 8 8 ,motion ,work1 #bie 8 8 ,pendulums1 #fe 8 8 ,stop ,works1 #bhg 8 8 ,suspension1 #fe 8 8 ,time ,trains1 #beh ,trains1 #ccj 8 ,electric1 #chi 8 ,regulator1 #dib 8 ,table of1 #beh 8 ,to ,calculate1 #beg1 #bfd1 #big ,tropical ,year1 #cdh ,tubular ,chimes1 #cgd1 #dbb ,turning ,tools1 #dha ,v ,varnish for ,dials1 #dch 8 ,remover1 #def ,vibrations of ,balance1 #ahj ,w ,warning1 #cjf1 #cab 8 ,pin1 #cjf1 #cab 8 ,wheel1 #cjf1 #cab ,weight ,cords1 #bfh ,weight of ,lead1 ,zinc and ,cast ,iron ,cylinders1 #cg ,weights1 #bfe1 #cai 8 ,auxiliary1 #cg 8 ,calculations of1 #bg 8 ,top1 #ci ,wheel ,contrate1 #aga1 #cge 8 ,crown1 #aga 8 ,hour1 #bif 8 ,cutting1 #bed 8 ,leverage of1 #ii 8 ,measuring1 #aie 8 ,minute1 #if1 #bic1 #bif1 #cbe 8 ,sizes of1 #bja1 #dij 8 ,stamping1 #bef 8 ,star1 #ccb1 #cce 8 ,stretching1 #bbf ,wires1 ,gong1 #cfi ,y ,year1 #cdh 8 ,leap1 #cdi 8 ,sidereal1 #cdi 8 ,tropical1 #cdh ,z ,zinc1 #ed ,big ,ben ,illustration ,,big ,,ben is the first and only alarm sold exclusively to jewelers4 ,he is without exception the finest sleepmeter made--the best looking1 the best built1 the best running4 ,big ,ben is a beautiful thin model alarm clock standing #g inches tall and mounted in a reinforced triple plated case4 ,he is fitted with big strong easy winding keys1 clean cut heavy hands and a large open winsome dial1 distinctly visible across the largest room4 ,big ,ben rings just when you want and either way you want1 intermittently for fifteen minutes1 continuously for ten1 and he rings with a jolly full-tone ring that will arouse the drowsiest sleeper4 ,big ,ben is rigidly inspected1 six days factory timed and tested4 ,he works only for jewelers and then only for certain jewelers--those that agree to sell him for not less than #b4ej4 ,we pay his railroad fare on all orders for a dozen or more1 we brand him with your name in lots of #bd4 ,height #g inches4 ,dial #d inches4 ,intermittent or ,long ,alarm4 ,dealers' names printed free on dials in lots of #bd4 ,freight allowed on orders for one dozen or more4 ,western ,clock ,mfg4 ,co4 ,new ,york ,la ,salle1 ,illinois ,chicago ,,horological ,,department--,bradley ,polytechnic ,institute ,illustration ,,this entire building used exclusively for instruction in watchwork1 jewelry1 engraving and optics1 is thoroughly equipped with all modern tools for use in connection with the work as required in any up-to-date jewelry store4 ,competent instructors as heads of each department and several assistants1 so that all may be kept busy4 ,if you would like to get all or any one of the branches mentioned above1 it will pay you to investigate ,bradley4 ,with our increased facilities we can take care of all who wish to come4 ,don't put off till tomorrow or next week the sending of a post card addressed to ,,horological1 ,dept4 ,a41 ,peoria1 ,ill41 asking for one of our latest books telling all about ,modern ,methods as applied at this truly great institution4 ,,self ,,winding ,,clock ,,co4 ,,new ,,york ,self ,winding ,synchronized ,clocks1 ,primary and ,secondary ,clock ,systems1 for ,railroads1 ,public and ,office ,buildings1 ,hotels1 ,universities1 ,colleges1 ,schools and ,private ,residences4 ,self ,winding ,program ,instruments1 ,jewelers' ,regulators1 ,bank ,clocks1 ,tower1 ,post and ,bracket ,clocks4 ,making ,clocks to ,architects' designs a specialty4 ,hourly signals of correction from the ,u4 ,s4 ,observatory at ,washington1 ,d4 ,c4 over the lines of the ,western ,union ,telegraph ,co4 ,illustration ,,meyer ,,jewelry ,,co4 ,kansas ,city 33 ,mo4 ,for ,rush ,orders ,tools1 ,materials and ,optical ,goods ,,meyer ,,jewelry ,,co4 ,kansas ,city 33 ,mo4 ,illustration ,in #ahed ,waltham ,watches awakened ,europe to the fact that the ,american method of manufacturing produces the best watches4 ,since that time the burden of proof has been successfully carried by #ag1jjj1jjj ,,waltham ,,watches all representing the highest stage of the watchmakers' art4 ,howard ,clocks ,are modern in the sense that they are the best timekeepers in the world although we have been making them since #ahdb1 when our business was established by ,edward ,howard4 ,we guarantee satisfaction and respectfully solicit your business4 ,the ,e4 ,howard ,clock ,co4 ,,boston1 ,,new ,,york ,,and ,,chicago ,makers of ,clocks but only of the highest grade in their respective lines ,jewelers' regulators1 electric clocks1 house and office clocks1 locomotive and engine room clocks1 marine clocks1 programme clocks1 post or side walk clocks1 tower clocks1 watchman clocks1 employees' time recorders4 #e ,ingersoll-,trenton -- to ,the ,best ,seven ,jewel ,watch #ae ,,guaranteed ,illustration ,the first watch guarantee ever issued was that placed on the cheapest watch ever made--the ,dollar ,watch--nineteen years ago4 ,for those nineteen years while selling nearly nineteen million ,ingersoll watches1 we have been asking3 8,why are expensive1 jeweled watches not guaranteed80 ,the ,ingersoll-,trenton is the first and only ,illustration high grade #g-;jewel watch made complete and cased in one factory2 and therefore1 the only one that can be guaranteed by its makers2 others are assembled from movements made in one factory and cases from another1 by the dealer1 often a competent jeweler1 but often1 too1 without facilities such as the adjusting and timing systems existing in our complete watch factory4 ,the 8,i-,t0 has all features of the most recent1 costly watches1 which secure accuracy4 8,i-,t0 gold-filled cases contain gold enough to outlive their guarantees4 ,sold only through responsible jewelers1 who buy direct4 ,if not on sale in your town we will send1 prepaid express1 on receipt of price4 ,,ingersoll ,,watches ,for seventeen years there has been but one standard in everyday watches2 8,ingersolls0 have popularized the very use of watches4 ,one friend says1 8,they have made the dollar famous40 ,they have never been so worthy of their great reputation as to-day4 ,fully guaranteed4 ,they include2 ,the ,dollar ,watch2 the 8,eclipse0 at #a4ej2 the new thin model 8,junior0 at #b4jj2 and the 8,midget0 ladies' size at #b4jj4 ,sold by #fj1jjj dealers or post-paid by us4 ,,robert ,h4 ,,ingersoll ,,bro4 ,new ,york ,chicago ,london ,san ,francisco ,,the ,,great ,,american ,,catalogue ,have you added this ,salesman to your selling force8 ,purchasing ,goods from the ,great ,american ,catalogue insures prestige and the confidence your customers will bestow upon you will be apparent in increased patronage4 ,our ,catalogue meets with cordial approbation of old stand-by customers who are in a position to judge of the meritorious results obtained through constant use1 as the best purchasing medium4 ,please permit us to send you a copy4 ,the ,oskamp-,nolting ,co4 ,no4 #daa-dac-dae-dag ,,elm ,,st4 ,cincinnati 33 33 33 ,ohio4 ,,moseley ,illustration ,made ,continuously ,imitated--but for over #cj years ,,never ,,equaled ,the ,standard of ,excellence ,nothing is overlooked in their manufacture and no expense is spared to make them ,,right4 ,the ,genuine ,moseley ,lathe of to-day is the result of years of painstaking1 systematic and skilled endeavor to satisfy the exacting requirements of the most critical and experienced workmen4 ,moseley ,chucks are of the best quality1 and are made in all sizes2 covering every need of the ,watchmaker and ,repairer4 ,these ,chucks and ,lathes were manufactured by us for years under the direct supervision of ,,chas4 ,s4 ,,moseley1 the inventor of the 8,split ,chuck0 and 8,draw-n-,spindle40 ,moseley ,lathes and ,attachments1 with plenty of ,moseley ,chucks are the secret of rapid and accurate work4 ,they increase your earning power by enabling you to do more work in a day4 ,as an investment they pay big dividends4 ,write your ,,jobber for the ,,new ,,moseley ,,catalog--,,instruction--,,reference ,,book ,no4 #aa 8,,you ,,need ,,it ,,every ,,day40 8,,there',s ,,no ,,lathe ,,like ,,the ,,moseley0 ,clock ,tools and ,clock ,materials form an important and extensive item of stock in our ,tool and ,material ,department1 at ,,prices ,,that ,,defy ,,competition ,illustration ,no4 #bigi4 ,clock ,main ,spring ,winder4 ,nickel plated1 #j4ej ,in ,clock ,springs1 we keep the best polished only2 our stock consisting of all the most desirable widths on the market4 ,if you do not possess our large ,tool and ,material ,catalogue1 kindly send us your business card and procure one4 ,we can save you time1 money and annoyance2 we are anxious to make your acquaintance1 as we treat our customers with the utmost courtesy and attention4 ,a trial order solicited4 ,otto ,young ,co4 ,wholesale ,jewelers and ,importers and ,jobbers ,diamonds1 ,watches1 ,clocks1 ,jewelry1 ,tools1 ,materials and ,optical ,goods4 ,heyworth ,building1 ,chicago 99 99 99 99 99 99 ,transcriber's note3 ,illustrations have been moved so they do not break up paragraphs4 ,typographical errors have been silently corrected4 ,the 8,,table ,,of ,,contents0 was added by the transcriber4 ,it was not part of the original text4