,illustration ,,scientific ,,american ,,supplement ,,no4 #dib ,,new ,,york1 ,,june #f1 #ahhe4 ,scientific ,american ,supplement4 ,vol4 ,,xix1 ,no4 #dib4 ,scientific ,american established #ahde ,scientific ,american ,supplement1 #e a year4 ,scientific ,american and ,supplement1 #g a year4 99 99 99 99 99 ,,table ,,of ,,contents4 ,i4 ,,engineering ,,and ,,mechanics4--,the ,new ,spanish ,artillery4--#b engravings4 ,qualitative ,tests for ,steel ,rails4--,by ,l4 ,,tetmajer4 ,a ,new ,form of ,small ,bessemer ,plant4--,by ,a4 ,,trappen4 ,triple ,compound ,engines4--,a paper read by ,a4,e4 ,,seaton before the ,institution of ,naval ,architects4 ,early ,history of the ,steam ,jack4 ,bridge over the ,river ,adige1 at ,verona4--#ac figures4 ,pumping ,machinery4--,mine pumps4--,direct acting steam pumps4 ,by ,e4,d4 ,,leavitt4 ,improved ,gun ,pressure ,gauge4--#b figures4 ,measuring the ,thickness of ,boiler ,plates4 ,on an ,express ,engine4 ,,ii4 ,,technology4--,improved ,plaiting ,machine4--,with engraving4 ,self-acting ,shuttle ,guard4--#a figure4 ,ruler and ,triangle for ,hatching4 ,the ,distillation of ,sea ,water4--#a figure4 ,aids to ,correct ,exposure on ,photographic ,plates4--,an interesting paper by ,w4 ,,goodman4 ,isochromatic ,photography4--,by ,,fred4 ,e4 ,,ives4--#b figures4 ,distortion from ,expansion of the ,paper in ,photography4 ,,iii4 ,,electricity1 ,,etc4--,on the ,fritts ,selenium ,cells and ,batteries4--,a paper read before the ,american ,association by ,c4,e4 ,,fritts4 ,electricity ,applied to the ,manufacture of ,varnish4--#b figures4 ,naglo ,brothers' ,telephone ,system4--#c figures4 ,the ,gerard ,electric ,lamp4--#a figure4 ,a ,new ,reflecting ,galvanometer4--#c figures4 ,,iv4 ,,art ,,and ,,architecture4--,groups of ,statuary for the ,pediment of the ,house of ,parliament in ,vienna4--#b engravings4 ,the ,casino at ,monte ,carlo4--,an engraving4 ,v4 ,,physics4--,determining the ,density of the ,earth4--#a figure4 ,physics without ,apparatus4--,the ,porosity and ,permeability of ,bodies4--,a ,hot ,air ,balloon4--#b engravings4 ,,vi4 ,,natural ,,history4--,winter and the ,insects4--,an engraving4 ,silk ,worm ,eggs4--,with engraving4 ,,vii4 ,,horticulture4--,the ,melleco4--,ullucus tuberosa4--,with engraving4 ,,viii4 ,,physiology1 ,,medicine1 ,,etc4--,histological ,methods4--,section cutting machines4--,methods of preserving the tissues4--,preservative media4--,preparation for mounting tissues4--#a figure4 ,life ,history of a ,new ,septic ,organism4 ,erythroxylon ,coca as a ,therapeutic ,agent4--,by ,dr4 ,e4,r4 ,,squibb4 99 99 99 99 99 ,,new ,,spanish ,,artillery4 ,the ,spanish ,government is now engaged in supplying some of its principal fortifications with heavy guns of the most improved construction4 ,the defenses of ,cadiz and ,ceuta have been greatly strengthened in this respect4 ,the most recent additions are some very powerful ,krupp guns for the fortress of ,isabel ,,ii41 at ,mahon4 ,illustration3 ,,new ,,krupp ,,breech ,,loading ,,guns ,,for ,,spanish ,,fortifications4 ,we give engravings from photographs1 as presented in ,la ,illustracion ,espaola4 ,these guns are breech loaders1 of steel1 #cj centimeters caliber1 or #ab inches1 #di tons weight4 ,illustration3 ,,new ,,krupp ,,breech ,,loading ,,guns ,,for ,,spanish ,,fortifications4 ,one of our engravings shows the great revolving crane by which the guns were lifted and placed on the truck for conveyance over a track to their intended position4 ,this crane is worked by eight men1 and readily lifts burdens of about #bjj1jjj lb4 ,the other engraving shows the jack frame and jacks employed to remove the gun from the temporary truck4 ,at a range of #g1jjj yards these guns are able to penetrate iron plates of two feet thickness4 99 99 99 99 99 ,,qualitative ,,tests ,,for ,,steel ,,rails4 ,by ,mr4 ,l4 ,,tetmajer4 ,this memoir is the first of a series upon the unification of nomenclature and classification of building materials1 undertaken by the author at the request of the ,swiss ,engineers' and ,architects' ,union4 ,for its preparation numerous mechanical tests have been made upon steel rails1 both good and bad1 taken from the ,swiss railways1 while the corresponding chemical analyses have been made by ,dr4 ,treadwell in the ,polytechnic ,laboratory1 at ,zurich4 ,the results are given for twenty-two examples1 about one-half of which have stood well1 while the remainder have either broken1 split1 or suffered considerable abrasion in wear2 but in many instances the mechanical test of tensile strength1 elongation1 and contraction1 and the figures of quality 7,wohler's sum and ,tetmajer's coefficient7 deduced from these have varied very considerably for the results obtained in practice4 ,the best wearing rails1 which often give contradictory results with the tensile test1 were comparatively pure manganese steels1 low in silicon1 only exceptionally up to #j4b per cent41 but generally below #j4a per cent41 and with less than #j4a per cent4 of phosphorus and sulphur4 ,on the other hand1 rails with a tendency to break or split are low in carbon1 with variable proportions of manganese1 but contain much silicon1 #j4c to #j4i per cent41 and often above #j4a per cent4 of phosphorus4 ,another series of experiments upon rails for the ,finland lines made by the author in #ahgi-hj shows the high quality of manganese steel4 ,these are essentially highly carburized 7#j4c-j4d per cent4 carbon7 with #j4g to #a4d per cent4 manganese1 and have stood three and a half years' wear without a single one being broken2 while those of silicon steel with #j4ajf-j4add per cent4 carbon1 #j4eib-j4hbh manganese1 and #j4dbc-j4dce silicon have failed in many cases1 showing a great tendency to split4 ,in both of the latter instances1 however1 the figures deduced from tensile tests of both good and bad specimens were substantially the same4 ,the causes of the difference between the two kinds of steel the author attributes to differences in the structure of the ingot due to the agent used in chemical consolidation1 which may be either manganese or silicon1 which structures are illustrated by photographs of ingot fractures4 ,when silicon is used there is a tendency to unsoundness about the exterior of the ingot1 which is surrounded by a honeycomb-like cellular casing of greater or less depth2 while with manganese the vesicular cavities are more or less dispersed through the whole substance1 or concentrated toward the interior of the ingot4 ,rails made from the former are1 therefore1 more likely to contain unsound portions near the outer wearing surface1 and to give unsatisfactory results in wear1 than those from the latter2 but as the test pieces are usually cut from the center of the railhead1 the tensile resistance of the interior may be equal to or surpass that of the superior material4 ,in summing up his observations the author concludes that the method of tensile testing is mainly of value in determining the quality of the material1 but that for the finished product properly arranged falling weight tests are necessary4 ,he also considers that the test pieces should be flat bars of #b4e to #c4e centimeters in area1 cut as near as possible to the outer surface of both head and foot of the rail4 ,he reprobates especially the research for microscopic imperfections 7mikrobenscherei7 upon the fractured surfaces1 as an annoyance to the producer1 and perfectly useless to the consumer4--,stahl und ,eisen1 vol4 iv41 page #fjh2 through ,proc4 ,inst4 ,civ4 ,eng4 99 99 99 99 99 ,a ,,new ,,form ,,of ,,small ,,bessemer ,,plant4 ,by ,mr4 ,a4 ,,trappen4 ,the success of the ,bessemer process when carried out on the small scale at ,avesta in ,sweden1 as described by ,professor ,ehrenwerth1 and subsequent experiments of a similar kind made at ,pravali1 in ,carinthia1 and elsewhere1 have led the author1 who is specially occupied in the building of ,bessemer works1 to design a plant suitable for operation upon small charges4 ,this consists essentially of a converter about #a meter outside diameter1 and #a4e meters high1 connected by a single trunnion to a horizontal steel shaft carried by the arm of a hydraulic crane which is very similar in character to the ladle crane of a large sized converter4 ,the sweep of the crane is such as to allow the converter to be brought close up to the tap hole of the blast furnace or cupola1 so that the use of open gutters for the fluid metal may be avoided as much as possible4 ,the converter is turned on its axis by a screw and worm wheel1 which is manipulated by a workman standing on a platform at the opposite arm of the crane4 ,the blast is brought in from above by a pipe down the central pillar of the crane1 which is connected with the blast-main by a flexible tube and packed joint4 ,the outer trunnion bearing is open1 so that by slightly raising and lowering the ram of the crane1 the converter may be left suspended to a weighing machine in front of the furnace1 if it is required to determine the weight of the charge4 ,when the converter is filled1 it is borne by the crane into a convenient position for blowing1 and if the basic method is followed for removing the slag1 the converted metal is cast into ingot moulds1 which are manipulated by a small ingot crane of the ordinary pattern4 ,in the case of small existing blast-furnaces1 which usually have their tap holes near to the ground1 it may be necessary to have a shallow ingot pit 7#bj to #bd inches deep72 but with cupolas this will not generally be necessary1 and the whole of the operations may be carried on at the ground level4 ,each crane is intended to be supplied with two or three converters1 so that operations may be carried on continuously4 ,the weight of charge proposed is #ae cwt41 which should under ordinary conditions give #ab cwt4 of ingots4 ,taking the time of a single converting operation at half an hour it will be easy to obtain fifty blows per day1 or a production of #cj tons4 ,this may be easily increased by placing a second converting crane on the other side of the furnace1 for which the same blowing engine will be sufficient1 as the actual blowing time will not exceed twelve minutes4 ,the labor required for each converter will be about six men per shift4 ,the blast required has been experimentally determined at #dj-ej cubic meters per minute at #ae lb4 pressure4 ,this will be supplied by a single cylinder engine of #ijj millimeters blast1 and #ghf millimeters steam piston1 diameter #ghf millimeters1 stroke making fifty revolutions per minute1 which is also to work a ,root blower and the accumulator pumps4 ,having regard to these very different demands upon the power of the engine1 it will be provided with expansion gear1 allowing a considerable variation in the cut-off4 ,a single boiler of #gj to #ge square meters heating surface will be sufficient4 ,the accumulator is intended to work at #cjj lb4 pressure4 ,the cost of the plant1 including one of each of the following items1 converter1 converter truck1 blowing engine1 accumulator1 ingot crane1 centesimal weighing machine1 and accumulator pump1 is estimated at #b1jej to #b1ajj2 and that of the steam boiler1 #cbe4 ,the buildings may be of the simplest and cheapest possible character4 ,as the productive power of such a plant contrasts very favorably with its cost1 the author considers that it may be fairly expected to meet the competition of large works1 especially in the manufacture of a high-class product4--,stahl und ,eisen1 vol4 iv41 page #ebd2 through ,proc4 ,inst4 ,civ4 ,eng4 99 99 99 99 99 ,,triple ,,compound ,,engines4 ,footnote3 ,paper read before the ,institution of ,naval ,architects1 ,march #bg1 #ahhe4 ,by ,mr4 ,a4,e4 ,,seaton4 ,my attention was first called to the modern triple compound engine by the published reports of the trial trip of the yacht ,isa1 and in it ,i plainly discerned the germs of a successful new type of engine2 but it was not until ,i had seen the engines of the screw steamer ,aberdeen erected in the workshops of ,messrs4 ,robert ,napier ,sons that ,i became convinced that it was the engine of the immediate future4 ,it is1 however1 due to the farsightedness and enterprise of ,mr4 ,c4,h4 ,wilson1 ,m4,p41 that ,i was enabled to try the merits of the new system and compare it with the old4 ,mr4 ,wilson had already viewed the triple compound engine with more than ordinary interest1 and it required little persuasion on my part to allow the company to which ,i have the honor to belong to construct a triple expansion engine in lieu of the ordinary compound for one of four sister ships which it then had in hand for ,messrs4 ,thomas ,wilson1 ,sons ,co41 the latter only stipulating that it was to be of the same power as the engine already contracted for4 ,as ,i was quite convinced that economy was due to the system rather than to the higher pressure1 it was decided not to increase the boiler pressure more than was necessary to suit the triple system4 ,the other three ships already alluded to were being fitted with engines having cylinders #be inches and #ej inches diameter by #de inches stroke1 and supplied with steam of #ij lb4 pressure from a double ended boiler #ac feet #i inches diameter by #ae feet long1 having a total heating surface of #b1caj feet1 so that these engines have every qualification for being economical so far as general proportions go1 the stroke being an abnormally long one and the boiler of ample size4 ,experience has since shown that these engines are economical in coal1 and the wear and tear exceptionally small4 ,the new engines for the fourth boat were made with considerably shorter stroke1 and the cylinders proportioned so as to give equal power2 they are #ba inches1 #cb inches1 and #ef inches diameter by #cf inches stroke1 the high pressure cylinder being supported on columns immediately over the medium cylinder1 and in other respects these engines were made as near as possible like the other ones above named4 ,steam at #aaj lb4 pressure is supplied from a double ended boiler #ab feet #i inches diameter and fifteen feet long1 having a total heating surface of #b1bgj square feet1 and identical in design with the boiler supplied for the other engines4 ,the propellers were made exactly alike in all respects1 and the ships being likewise precisely alike1 a comparison of the performances of the one fitted with the triple engines could be made with as little grounds for differences of opinion as is possible4 ,one of the ships fitted with the ordinary compound engines was named the ,kovno1 that with the triple compound engines the ,draco4 ,their dimensions are as follows3 ,feet4 ,inches4 ,length between perpendiculars4 #bgj #j ,breadth4 #cd #j ,depth of hold4 #ah #c ,and of #a1gjj tons gross register4 ,they are ordinary cargo boats1 built of steel1 having a raised quarter deck and long bridge amidships1 but nothing about them otherwise requires comment4 ,after making a voyage or two to the ,baltic1 and finding that everything was working satisfactorily1 the ,kovno was loaded with #b1djj tons dead weight1 and sailed in ,january1 #ahhc1 for ,buenos ,ayres2 the ,draco was loaded with #b1dbe tons dead weight1 and sailed ,march1 #ahhc1 for ,bombay1 the distance in both cases being about #f1djj miles4 ,it was thought advisable1 for purposes of comparison1 that the ships should steam at as near as possible the same speed2 and to attain this object1 we considered the safest plan was to instruct the engineers as to the average amount of coal they were to burn per day1 and experience with these ships on their ,baltic voyages had fixed this at #ab tons in the case of the ,kovno and #aj tons in the case of the ,draco4 ,during the voyage each ship seems to have had fair average weather1 and equal care was taken in getting the best results possible4 ,the average speed of the ,draco was1 however1 #h4fbe knots1 or #bjg miles per day1 the engines making on the average #eg4e revolutions per minute1 while the ,kovno did only #h4a knots1 or #aid miles per day1 the engines making #ee4e revolutions4 ,the coal used was ordinary ,south ,yorkshire1 just as it comes from the pits for bunker purposes4 ,the indicated horse power in each case would average about #fjj4 ,the total coal consumed was #cbf tons in the ,draco and #dje tons in the ,kovno1 or a saving of #ai4e per cent4 over the ordinary compounds1 with an increase of speed of #f4e per cent4 ,in ,december1 #ahhc1 one of the others1 the ,grodno1 sailed from ,bombay1 and attained an average speed of #h4e knots1 or #bjd miles per day1 the engines making #eg revolutions1 with a coal consumption of #ab4h tons per day1 or #dfi tons on the voyage4 ,the ,draco's consumption is therefore #cj4e per cent4 less than that of the ,grodno on the round voyage1 and #bj4c percent per day4 ,the success of the triple compound engine was in these instances more than had been anticipated1 and induced ,mr4 ,wilson to go a step further4 ,the ,s4,s4 ,yeddo had been refitted with boilers made for a working pressure of #ij lb4 per square inch1 but owing to the size of the shafting the working pressure was limited to #gj lb42 the average consumption of coal under these circumstances on two voyages was #ag tons per day4 ,these boilers had a margin of safety beyond what was required by the rules when made1 and as the ,board of ,trade rules had been modified in the mean while1 it was found that they could with safety be worked at #ajj lb4 per square inch4 ,a third cylinder was now fitted on the top of the original low pressure1 and the safety valves loaded to the #ajj lb41 and the ship was dispatched to ,cronstadt4 ,after making two voyages under similar circumstances to the two previous ones1 the average consumption was #ac4e tons per day only4 ,in this case it was the same ship1 same boilers1 same engines1 same propeller1 and same men1 the only difference being the addition of a third cylinder and the increase of pressure4 ,so far all the trials had been made with two crank engines2 so it was now decided to construct another set of engines for #aej lb4 pressure1 having a crank to each cylinder4 ,these engines had cylinders #bj inches1 #cc inches1 and #eh inches diameter by #cf inches stroke1 and were fitted into the screw steamer ,rosario1 whose dimensions are #bge feet #c inches between perpendiculars1 #cd feet #c inches beam1 and #ai feet #b inches depth of hold1 #a1hfb tons gross1 and the deadweight capacity #b1eej tons4 ,in ,march last year she was loaded with #b1ecj tons deadweight1 and did the voyage to ,bombay at an average speed of #h4f knots on a consumption of #aj4e tons per day of ,south ,yorkshire coal1 and burnt on the voyage #cdg tons4 ,this result is superior to that of the ,draco when the size of the ship is taken into account1 but is not so much so as might have been anticipated from the increase of pressure and the rate of expansion1 which was #ad4d in the ,rosario and #ab in the ,draco4 ,another set of engines was made from the patterns of those of the ,draco1 but with the high pressure cylinder #bj inches diameter1 steam at #aej lb4 pressure being supplied from two single ended boilers1 having a total heating surface of #b1bjj square feet4 ,they are fitted in the ,s4,s4 ,finland1 a cargo boat #bgj feet long1 #ce feet beam1 by #ah feet depth of hold1 and #a1ied tons gross register4 ,in ,january she was loaded with #b1ejj tons deadweight1 and sailed for ,rangoon4 ,the average speed attained was #h4db knots per hour1 or #bjb miles per day1 on a consumption of #aj4c tons of ,welsh coal per day1 the rate of expansion being #ab4 ,it should be mentioned that all these ships named are fitted and steered with steam stearing gear1 so that in comparing these results and those published of the engines made by an eminent engineer in the north of ,england1 an allowance should be made1 as in that ship there was no steam stearing gear4 ,i have chosen to make all these comparisons by reference to the ships' logs1 and to give results such as a shipowner looks for rather than those which engineers prefer to use in forming a judgment on the merits of different engines4 ,i do this for two reasons3 first1 because the commercial success of the triple compound engine depends on the saving it can effect in a long voyage2 and secondly1 because ,i had no reliable indicator diagrams from which the consumption per indicated horse power could be calculated with any degree of accuracy4 ,on trial trips with the steamers already named1 the consumption of ordinary ,south ,yorkshire coal was #a4f lb4 per indicated horse power1 and the consumption of water per indicated horse power calculated from the high pressure indicator diagrams was #a4da in the ,draco1 #ac4b in the ,rosario1 and #ac4af with the ,finland1 or taking the medium pressure diagrams1 it was #ab4b1 #a4cj1 and #aa4ie respectively4 ,twelve months ago we constructed for ,messrs4 ,thomas ,wilson1 ,sons ,co41 two sets of triple expansion engines of #fjj indicated horse power1 one having two cranks and the other three cranks1 the engines1 boilers1 and propellers being otherwise exactly alike and fitted into sister ships4 ,the water consumed in the three crank engine is #ab4ic lb41 against #ac4j in the two crank1 but the former drives its ship nearly knot per hour faster than the latter does its1 and when both ships are driven at the same speed the consumption of coal in the three crank ship is considerably less than in the other4 ,we have now entirely given up the construction of two-crank triple expansion engines1 because of the impossibility of equally dividing the work between the cranks2 for1 although the engine when running appeared to be perfectly balanced1 the wear of the brasses of the crank having the two cylinders was always considerably more than that of the other4 ,placing the high pressure cylinder over the low pressure cylinder seemed to give the most satisfactory results1 but even these were far inferior to those once obtained with the three cranks4 ,we have lately constructed some very small three-crank engines from which exceedingly good results were obtained2 the cylinders are only #aa inches1 #ag inches1 and #cj inches by #ah inches stroke1 which developed #bah indicated horse power with a consumption of #ab4h lb4 of water per indicated horse power1 and this1 together with some other observations1 leads me to believe that the best economical results will be obtained by running triple expansion engines at a much higher number of revolutions than is usual1 and with a rate of expansion not less than #ab for a steam pressure not less than #adj lb4 7#aee absolute74 ,the largest engines we have made of this type so far are those of ,s4,s4 ,martello1 which have cylinders #ca inches1 #ej inches1 and #hb inches diameter by #eg inches strokes and indicate at sea #b1djj horse power when running at #fj revolutions with steam of #aej lb4 pressure2 the consumption of ,yorkshire coal is #cg tons per day average throughout a ,new ,york voyage4 ,had ,welsh coal been used in every case1 the results would have been very much better1 for1 in addition to the superior evaporative power of ,welsh coal1 it is slow burning and much more easily controlled1 especially on the comparatively short grates of these modern boilers1 the quick-burning ,yorkshire coal causing the safety valves to frequently blow off when working near the load pressure unless great care is taken by the firemen4 ,i trust these few particulars may be of interest to the ,institution1 and especially to those members of it who are particularly interested in the commercial success of our mercantile navy4 ,i have purposely avoided engineering details and technicalities of any kind1 giving only such information as will tend to give ,british shipowners faith in that form of engine which will undoubtedly help them to successfully tide over bad times1 and keep the bulk of the carrying trade of the world in their hands4 99 99 99 99 99 ,,early ,,history ,,of ,,the ,,steam ,,jack4 ,to the ,editor of the ,scientific ,american3 ,a friend has brought me a copy of the ,,scientific ,,american ,,supplement1 of ,april #ah1 #ahhe1 containing an article about a steam jack4 ,says ,mr4 ,j4,g4 ,briggs1 in the ,american ,engineer3 ,of its origin nothing is known4 ,also the invention is attributed to ,benjamin ,baleh4 ,i can give you the true history of the steam jack4 ,it was invented by my grandfather1 ,john ,bailey1 of ,hanover1 ,plymouth ,county1 ,mass4 ,he was a minister of some note in the ,society of ,friends1 or ,quakers4--a man of superior mental ability1 but poor in purse1 for1 like all early inventors1 he reaped but little pecuniary benefit from his inventions4 ,among those inventions was the first iron sink in this country--if not in the world4 ,a few years ago that sink was in use at his old home in ,hanover4 ,he also invented the crooked nose for the tea-kettle4 ,previous to that the nose was straight4 ,both sink and tea-kettle were cast at the ,middleborough foundry4 ,when he made the steam-jack he said1 ,in less than fifty years the common mode of travel would be by steam4 ,people called him steam mad4 ,but about the jack4 ,we have one in our possession of which your cut is an exact copy4 ,we have used it several times4 ,we also have the parchment patent1 of which ,i send you a copy4 ,the jacks were not in general use1 for soon after the invention the tin kitchen1 or ,dutch oven1 as it was sometimes called1 was introduced1 and superseded the jack entirely1 as people were afraid of being blown up by steam4 ,the patent says1 ,john ,bailey1 of ,boston1 showing that at that early date ,boston was considered the ,hub1 and that it was considered a good thing to hail from there4 ,hanover is about twenty-four miles from ,boston4 ,trusting ,i have not wearied you1 ,i am1 ,,anna ,m4 ,,bailey4 ,bleak ,house1 ,lynn1 ,mass41 ,may #ab4 ,,copy ,,of ,,patent4 ,united ,states4 ,to all to whom these ,presents shall come1 ,greeting4 ,whereas1 ,john ,bailey1 of ,boston1 in the ,state of ,massachusetts1 hath presented a petition to the ,secretary of ,state1 the ,secretary for the ,department of ,war1 and the ,attorney-,general of the ,united ,states1 alledging and suggesting that he hath invented the following useful ,machine1 not before known or used1 that is to say3 ,a ,steam ,jack1 consisting of a boiler1 three wheels1 and two wallowers2 the steam which issues from boiling water in the said boiler gives motion to one of those wheels by striking on buckets on its circumference2 on the outer end of the axle of the wheel is a wallower1 the rounds of which fall into the teeth of a second wheel2 on the axle of this second wheel is another wallower1 the rounds of which fall into the teeth of a third wheel2 on the axle of which third wheel is a spit3 and praying that a patent may be granted therefor3 and1 whereas1 the said invention hath been deemed sufficiently useful and important3 ,these are1 therefore1 in pursuance of the ,act1 intitled an ,act to promote the progress of useful arts1 to grant the said ,john ,bailey1 his heirs1 administrators1 or assigns1 for the term of fourteen years1 the sole and exclusive right and liberty of constructing1 using1 and vending to others to be used1 the said invention so far as he the said ,john ,bailey was the inventor1 according to the allegations and suggestions of the said petition4 ,in ,testimony whereof ,i have caused these ,letters to be made patent1 and the ,seal of the ,united ,states to be hereunto affixed4 ,given under my hand1 at the ,city of ,philadelphia1 this twenty-third day of ,february1 in the year of our ,lord one thousand seven hundred and ninety-two1 and of the ,independence of the ,united ,states of ,america the ,sixteenth4 ,go4 ,,washington4 ,by the ,president1 ,,th4 ,,jefferson4 ,,city ,,of ,,philadelphia1 ,february #bc1 #agib4 ,i do hereby certify that the foregoing ,letters-patent were delivered to me in pursuance of the ,act intitled an ,act to promote the progress of useful arts3 that ,i have examined the same1 and find them conformable to the said ,act4 ,,edm4 ,,randolph1 ,attorney-,general of the ,u4,s4 ,,seal4 99 99 99 99 99 ,,bridge ,,at ,,verona4 ,illustration3 ,,bridge ,,over ,,the ,,river ,,adige1 ,,at ,,verona4 ,the iron bridge which spans the ,adige at ,verona1 of which we publish illustrations1 has been recently completed to replace an old masonry bridge built in the fourteenth century1 and which was destroyed by the celebrated flood of #ahhb4 ,in designing the new work two leading conditions had to be fulfilled1 namely1 that there should be a single opening of #bia ft4 between abutments1 and that this width should be left quite unobstructed1 for the river is subject to floods1 which are frequent1 and very violent and sudden4 ,for this latter reason an ordinary form of arch1 with the roadway above it1 was inadmissible1 since the waterway would be seriously obstructed2 the special form illustrated was1 therefore1 carried into execution4 ,the bridge1 as will be seen from ,figs4 #a1 #b1 #c1 and #g1 consists of two main arched girders1 with two vertical sides in lattice work2 these arches spring below the level of the roadway and rise to a considerable height above it1 in the center4 ,the horizontal girders carrying the roadway1 are connected to the arches by verticals of the form and section shown in the drawings4 ,the longitudinal girders are of double trellis1 as will be seen by reference to ,figs4 #a1 #ab1 and #af4 ,the following are the principal dimensions of the bridge3 ,ft4 ,in4 ,clear opening between abutments #bia #d ,rise of arch #cb #i ,width of bridge #cg #d ,depth of arched girders #d #g ,illustration3 ,,bridge ,,over ,,the ,,river ,,adige1 ,,at ,,verona4 ,the arched girders are connected together1 in the central portion1 by a system of diagonal bracing1 as is shown on ,figs4 #b and #g4 ,the carriage road on the platform consists of buckled plates resting on transverse girders spaced #f ft4 #f in4 apart1 and covered with road metal1 and for the sidewalks checkered plates are used4 ,the ironwork in the bridge weighs #djj tons1 and cost #h1djj l42 the abutments cost #c1fjjl41 making the total outlay on the structure #ab1jjjl4 ,the bridge was tested by a uniformly distributed load of #hb lb4 per sq4 ft41 and under this stress the arched girders deflected #a4jf in4 ,the horizontal and vertical oscillation of the bridge1 which were carefully observed and graphically recorded by special instruments1 were very slight4 ,the engineer of the work was ,mr4 ,g4,b4 ,biadego1 of ,genoa4--,engineering4 99 99 99 99 99 ,,pumping ,,machinery4 ,footnote3 ,a paper read at the ,montreal ,meeting of the ,british ,association4 ,by ,e4,d4 ,,leavitt1 ,,jr41 ,cambridgeport1 ,mass4 ,,mine ,,pumping ,,machinery4 ,one of the earliest steam engines1 of any size1 introduced into ,america1 was erected about the year #agfc1 at the ,schuylkill copper mine1 situated upon the ,passaic ,river1 in ,new ,jersey4 ,all its principal parts were imported from ,england2 and a ,mr4 ,hornblower 7the son1 it is believed1 of the well known engineer of that name7 came to this country for the purpose of putting up and running this engine4 ,at the time when the manufacture of the engines for the ,philadelphia ,water ,works was commenced1 and as late as the year #ahjc1 we find five engines1 in addition to the one above mentioned1 noticed as being used in this country3 two at the ,philadelphia ,water ,works2 one just about being started at the ,manhattan ,water ,works1 ,new ,york2 one in ,boston2 and one in ,roosevelt's sawmill1 ,new ,york2 also a small one used by ,oliver ,evans to grind plaster of ,paris1 in ,philadelphia4 ,thus1 at the period spoken of1 out of seven steam engines known to be in ,america1 four were pumping engines4 ,in the coal regions of ,pennsylvania1 a simple1 high pressure1 single acting ,bull engine has been extensively adopted2 the dimensions usually run from #cf inches to #hj inches in diameter1 and a very common stroke is #aj feet4 ,at the ,empire shaft1 in the ,schuylkill coal region1 there is a very fine pair of these engines1 with #hj inch cylinders1 working #bd inch pumps4 ,the stroke of both steam pistons and pumps is #aj feet4 ,these ,bull engines are placed either vertically or on an incline1 as is most convenient for the workings4 ,the water valves are made either double1 triple1 or four beat1 according as the pumps are large or small2 and the beats are usually flat1 and faced with leather4 ,many flap-valves are also in use4 ,these are frequently arranged on conical seats1 and work very well4 ,the ,bull engines1 from their strength and simplicity1 give very little trouble1 working year after year with astonishing freedom from accident and slight cost of repair4 ,no attempt is made to economize fuel1 which consists mainly of culm1 which would otherwise be wasted4 ,of late1 direct acting steam pumps placed under ground have found much favor with mine operators1 on account of their portability and small first cost4 ,they usually range in size from #h inch steam and #e inch water cylinders by #ab inch stroke to #hj inch stream and #ad inch water cylinders by #cf inch stroke4 ,great numbers of these pumps are in use all over the ,united ,states4 ,a pumping engine that is remarkable for its size and peculiarities of construction is located at the ,lehigh zinc mine1 at ,friedensburg1 ,pa4 ,it was designed by ,mr4 ,john ,west1 the company's engineer1 and built by ,merrick ,sons1 of the ,southwark ,foundry1 ,philadelphia4 ,it is a beam and fly-wheel engine1 the steam cylinder being #aaj inches in diameter1 with a stroke of #aj feet4 ,there are two beams on the same main center1 from the outer end of which a double line of bucket and plunger pumps is operated4 ,the crank-shaft is underneath the steam cylinder2 and there are two fly-wheels1 one on each end of said shaft1 the crank-pins being fast in the hubs of the same4 ,there are two connecting rods1 which are attached one to each end of an end beam pin #bh inches in diameter4 ,the main center and crank shafts are also #bh inches in diameter2 each of the two plunger holes is #bd inches by #cj inches in section2 and all the working parts are in proportion to those heretofore mentioned4 ,perhaps no mining district has ever had to contend against greater difficulties in pumping than have faced the engineers of the celebrated ,comstock lode1 ,virginia ,city1 ,nev4 ,the mines are of great depth1 in some instances #c1cjj feet2 and the water is hot1 rising to #afj degrees ,fahr4 ,the machinery collected at this location is of great variety and magnitude4 ,there are many ,davey engines1 both horizontal and vertical4 ,the ,union and ,yellow ,jacket shafts have compound fly wheel engines of very great power2 the former having a beam1 and the latter being horizontal1 with cylinders placed side by side1 and pistons connected to a massive cross-head1 from the ends of which connecting rods lead to crank pins located in the hubs of the fly-wheels1 which are overhung upon the ends of the main shaft4 ,from the center of the cross head1 a link runs to the main pump-bob1 which operates a double line of #af inch pumps1 #aj foot stroke4 ,the steam stroke is #ab feet4 ,depth of shaft1 #c1cjj feet4 ,the pumping machinery used in the iron and copper districts of ,michigan usually consists of ,cornish plunger pumps1 which are operated by geared engines2 the latter making from three to sixteen strokes to one of the pumps4 ,the largest plant of this type yet erected is that of the ,calumet and ,hecla copper mine1 at ,calumet1 ,mich4 ,there are two lines of pumps1 varying in diameter from #g inches to #ad inches1 and with an adjustable stroke varying from #c feet to #i feet4 ,the object of the adjustable stroke is to diminish the capacity of the pumps in the dry season4 ,each line of pumps is driven from a crank placed on a steel spur-wheel shaft #ae inches in diameter1 making ten revolutions per minute4 ,the mortise spur-wheels have a diameter of #bb feet at the pitch line1 with two rows of teeth1 each #ae inches face4 ,the pitch is #d4gb inches4 ,engaging with the mortise wheels are pinions of gun iron #d feet #f inches in diameter1 placed on steel shafts #ab inches in diameter1 and making #ej revolutions per minute4 ,the #ab inch pinion shafts are driven through mortise wheels #ab feet in diameter1 and #bd inches face1 by pinions #c feet #i inches diameter1 which make #afj revolutions a minute4 ,the pinion shafts are driven through a wire rope transmission from an engine located #ejj feet distant4 ,the rope wheels are #ae feet in diameter1 and make #afj revolutions a minute4 ,the engine is #d1gjj horse power1 and1 in addition to driving the pumping machinery1 does the hoisting and air compressing for the ,calumet mine4 ,in the same building with the mine pump gearing is a duplicate arrangement for operating the man engine4 ,in order to operate the mine pumps and man engine for the ,hecla mine1 it was necessary to use rock shafts1 which are made of gun iron1 and hollow2 they are #cb inches in diameter outside1 with #d inches thickness of metal4 ,the pump rock shaft is #ci feet #d inches long over all1 in two sections1 and weighs #dj tons4 ,there are rockers placed on each end of this shaft1 one of which is connected with a crank on the mortise wheel shaft1 and the other with the surface rods that work the pump-bobs4 ,these rods are of ,norway pine1 #ab inches by #ab inches in section1 and #a1jjj feet long4 ,there are two bobs1 one above the other1 with axes at right angles1 each weighing about #be tons4 ,the connection from the upper bob to the lower has hemispherical pins and brasses to accommodate vibrations in right angled planes4 ,the slope of the main pump is #ci degrees1 and the machinery has been designed to raise water from #d1jjj feet depth4 ,the pumps are of the usual ,cornish plunger type1 with flap valves4 ,there is an auxiliary engine1 of the ,porter-,allen type1 for driving the pumps and man engines when the main engine is not working4 ,it makes a #afj revolutions per minute1 the same as the rope wheels ,the seeming complication of the arrangement is due to the fact that it had to be adapted to existing works1 for increased depths1 and put in without interfering with the daily operation of the mine4 ,the ,calumet ,hecla ,mining ,company has also an extensive pumping plant at its stamp mills1 which are located on the shore of ,torch ,lake1 about four and a half miles from the mine4 ,there are located here #c pumping engines2 two of which have a capacity of #bj1jjj1jjj gallons a day1 and a third #aj1jjj1jjj gallons a day4 ,the water is elevated between #ej and #fj feet1 and is used for treating the stamped rock4 ,two of the engines are of the inverted compound beam and fly-wheel type2 and the third is a geared pump1 which has a horizontal double acting plunger1 #cf inches in diameter1 by six foot stroke1 driven from the crank of a spur-wheel shaft4 ,the spur wheel is #ab feet diameter1 #bd inches face1 and contains #if teeth4 ,the pinion engaging with it has #bg teeth1 and is fast on the fly-wheel shaft of a ,brown horizontal engine1 having a cylinder #ah inches in diameter1 and a stroke of four feet4 ,the steam pressure used is #aaj pounds per square inch2 and the engine has a ,buckley condenser4 ,the pump valves are annular1 of brass1 faced with rubber1 and close by brass spiral spiral springs4 ,their external diameter is six inches1 and the lift is confined to inch4 ,there are #ia suction and #ia delivery valves at each end of the pump4 ,the maximum speed of this pump is twenty-six double strokes a minute4 ,the largest of the compound engines is named ,ontario1 and has a vertical low pressure cylinder #cf inches in diameter1 and an inclined high pressure cylinder #ag inches in diameter2 the stroke of both being five feet4 ,these are inverted over a beam1 or rocker2 and the pistons are connected to opposite ends of the same4 ,the beam attachment of the main connecting rod is made to a pin located above and midway between the pins for piston connections4 ,the main center of the beam and the crank shaft have their pedestals in the same horizontal plane4 ,the throw of the crank is five feet4 ,there are two differential plunger pumps1 having upper plungers #bj inches in diameter1 and lower plungers #cc inches in diameter1 with a stroke of #e feet4 ,these pumps are vertical1 and placed beneath the engine bed-plate1 to which they are attached by strong brackets4 ,the pump under the low pressure cylinder is worked directly from its cross-head by an extension of the piston rod4 ,the other pump is worked by a trunk connection from the opposite end of the beam4 ,the radius of the beam is but fifty inches1 but the connections to it are made very long by links4 ,the lower plungers work through sleeves in diaphragms located in the center of the pumps4 ,in these diaphragms1 the openings for the delivery valves are made4 ,these valves are similar in construction to those previously described for the horizontal plunger pump4 ,their diameter1 however1 is but #e inches1 instead of #f inches1 and there are #gb suction and #gb delivery valves for each pump4 ,it will readily be seen that the action of these pumps is similar to that of the bucket and plunger2 each pump having one suction and two deliveries for each revolution of the engine4 ,the ,ontario is designed to run at a maximum speed of #cc revolutions a minute2 and the service required of it is to run regularly #add hours a week1 without a stop1 which is performed with the utmost regularity4 ,the differential pump was invented and patented1 many years since1 by a party named ,james ,ramsden1 in ,pennsylvania1 who designed it for an ordinary house pump4 ,it was subsequently reinvented by the writer1 who first ascertained that he was not the original inventor upon applying for a patent4 ,a pump of this description was run at the ,hecla mine for several years1 at a speed of #ejj feet a minute2 and its performance was in every way satisfactory4 ,,direct ,,acting ,,steam ,,pumps4 ,this class of machinery deserves a prominent place1 as the number in use vastly exceeds those of all other types combined4 ,the first consideration will be given to the ,worthington1 which is the pioneer of its type1 having been invented by the late ,henry ,r4 ,worthington1 and patented in #ahdd4 ,mr4 ,worthington's first pump was designed for feeding boilers4 ,his first water works engine was built for the city of ,savannah1 ,ga41 and erected in #ahed4 ,the second engine1 which was the duplicate of the ,savannah engine1 was erected at the city of ,cambridge1 ,mass41 in the year #ahef1 and was guaranteed to deliver #cjj1jjj gallons in twenty-four hours to an altitude of #ajj feet4 ,it had a high pressure cylinder #ab inches in diameter1 placed within a low pressure cylinder #be inches in diameter2 the low pressure piston being annular4 ,the double acting water plunger was #ad inches in diameter1 and worked directly from the high pressure piston rod2 the stroke of pistons and plunger being #be inches4 ,this engine was tested in #ahfj1 with the result of a duty equal to #gj1dfc1gej foot pounds per #ajj pounds of coal4 ,subsequently1 a test made by ,mr4 ,frederick ,graff1 of ,philadelphia 7long prominently connected with the ,philadelphia ,water ,department71 and the late ,erastus ,w4 ,smith1 of ,new ,york1 developed a duty of #ga1bgh1dhf foot pounds per #ajj pounds of coal1 which long remained the best record in the ,united ,states4 ,in #ahfc1 ,mr4 ,worthington brought out at ,charleston1 ,mass41 his crowning success1 the duplex engine1 which fairly deserves to be placed first among the hydraulic inventions of this century4 ,this engine has since been more extensively duplicated for water works purposes than any other1 with the possible exception of the ,cornish4 99 99 99 99 99 ,,improved ,,gun ,,pressure ,,gauge4 ,the following description of the construction and mode of action is by ,thomas ,shaw1 ,m4,e41 ,philadelphia1 the inventor4 ,illustration3 ,,improved ,,gun ,,pressure ,,gauge4 ,fig4 #a represents the gauge secured to small ordnance1 the gun shown in cross section4 ,fig4 #b represents face view of the gauge and indicator1 exposing a vertical section through the hydraulic portion of the gauge1 on line #c and #d of ,fig4 #a4 ,the same principles of reduction of high pressure are used in this gauge as in ,shaw's hydraulic gauge4 ,it will be observed that a solid steel piston1 ,e1 in the cylinder1 ,a1 is provided with a plunger on its under side1 which comes in contact with an elastic packing1 ,d2 the plunger may stand as #a to ,a #a1jjj1 or as #a to ,a #ajj1 in point of area of exposed surface1 as compared with the large piston head1 as desired4 ,assuming the proportions to be #a to ,a #a1jjj1 the #a1jjj lb4 pressure on the plunger means only #a lb4 pressure in the fluid chamber1 above piston head1 ,e1 and this greatly reduced pressure is now susceptible of measurement by any of the ordinary light pressure instruments for measuring pressures4 ,all the passage ways connecting to dial gauge1 ,r1 with the fluid chamber above piston1 ,e1 are filled solid with fluid1 permitting no air spaces that can be avoided4 ,the steel plug1 ,l1 that forms a passage way between the fluid chamber and the dial gauge1 is provided on one side with a small screw hydraulic pump1 with a reservoir supply of fluid4 ,this part is shown in longitudinal section2 the steel plunger1 ,i1 is firmly secured to wheel1 ,f1 the long hub1 ,h1 of which is provided with a screw thread on its inner side1 which thread screws upon the exterior of pump barrel1 ,k4 ,after first filling the interior of the pump barrel with fluid1 the said hub is screwed upon the pump barrel1 causing the plunger1 ,i1 to force the fluid into the fluid chamber and passage way leading to the dial gauge1 causing the hand or pointer to move to any predetermined pressure on dial1 in advance of pressure applied in the high pressure chamber at ,d4 ,the purpose accomplished in this act is to give the least possible movement of the pointer to record any maximum pressure1 as1 for example1 assuming that #bj1jjj lb4 was the expected pressure from any one explosive1 then the pointer1 by the means above described1 can be set at1 say1 #ah1jjj lb41 in which event the pointer is reduced to the minimum movement of only #b1jjj lb4 to register #bj1jjj lb4 ,it will be evident that much greater accuracy of measurement of maximum pressures can be obtained by the minimum movement of the pointer1 as both the inertia and the momentum are reduced to the minimum quantity4 ,the subsidence of pressure resulting from explosives being about as sudden as the creation of pressure1 causes the pointer to move too rapidly for correct ocular observation1 on which account a static electric current is employed1 causing a stream of electric sparks to shoot off from the end of the pointer1 ,b1 to the brass outer ring1 ,m4 ,the gauge is insulated for that purpose by glass plate1 ,s1 which is secured concentrically to the gauge proper and the ring1 ,m4 ,binding posts for the electric wires are provided at ,o and ,p1 which wires are shown in ,fig4 #b4 ,a spring clamp1 ,n1 ,fig4 #b1 enables the insertion of chemically prepared or other paper1 which lies against the inner side of brass rim1 ,m1 and held in place by the clamp1 ,n4 ,the electric sparks above spoken of pierce the strip of paper with small holes and colored marks4 ,these holes1 etc1 show the exact limits to which the pointer has traveled under pressure1 and thus an indelible record is kept by the electrical indications shown upon the strip of paper4 ,the paper can have the pressures corresponding to gauge printed upon the same1 when the holes are made prominent by holding the paper to the light1 exposing an exact indication of the pressures or explosives operated with4 ,the gases resulting from the explosives are injurious to the gauge packings1 etc41 on which account the bore in gun1 ,w1 and the connecting steel plug1 ,b1 are filled with fluid4 ,a screw plug1 ,u1 enables the insertion of the fluid1 after first pushing an elastic wad of rubber1 ,b1 or cork1 in the bore near the inner wall of the gun1 which wad will prevent the escape of the fluid to the interior1 and be sufficiently free to prevent any interference with the pressures4 ,the patentee and manufacturer of this gauge is prepared to fill orders up to #ej1jjj lb4 per square inch4 ,this gauge is made of the best steel1 and is very compact1 the weight being inside of twenty-five pounds4 ,the inventor has heretofore made mercury column gauges for gunpowder pressures1 which were too large for direct attachment to guns1 but were connected with special powder chambers to test the pressure1 etc41 of confined explosives4 ,the experience thus gained enabled the construction of the instrument here shown1 which is adapted to direct attachment to the gun1 making it as easy now to measure gunpowder pressures as it had been1 heretofore1 to measure steam pressures4 ,the effect of this movement is to reduce the exaggerated statement of high pressures1 obtained from ordinary sporting powders2 these have been accredited with pressures up to #dj1jjj lb4 per square inch1 but they only really gave #bb1jjj lb4 by actual gauge measurement4 ,artillerists and ordnance officers have1 in this instrument1 a true pulse of the internal pressures of the gun1 of inestimable value when determining the quantity of powder and the proper weight of shot4 ,these are important matters in ordnance practice4 ,this gauge is a compact machine1 designed to measure and indicate the quick pressures resulting from gunpowder explosives and the slow pressures of hydraulic force2 the same mechanism used in both cases permits the ready testing and examination of gauge under hydraulic pressure1 to determine its accuracy1 for the more sudden pressure occasioned by the use of gunpowder4 99 99 99 99 99 ,,improved ,,plaiting ,,machine4 ,the principal object the inventors of the machine we illustrate herewith had in view in designing it was to arrange a mode of working the grip motion positively1 so that the cloth shall be received freely and without strain or friction before or up to the very instant at which each fold is completed1 and shall then be seized and firmly held4 ,in existing machines there is not we believe1 any arrangement for the accomplishment of this purpose2 it is true1 the table upon which the cloth is folded is relieved at the termination of the stroke of the plaiting knife1 but the upper gripper bar1 against which the folds of cloth are pressed upon the return of the table to its normal position1 is stationary1 being rigidly fixed to the sides of the machine4 ,one result of this rigidity is that the cloth has to be forcibly thrust by the plaiting knife under the upper gripper bar1 and in consequence of the violence involved the fold just made at the opposite end is dragged out from the grip1 making a short fold1 and further1 in the case of delicate finishes1 giving rise to damaged goods4 ,another result of this arrangement1 when the cloth is not pressed against the upper bar1 is that it returns with the return stroke of the plaiting knife1 the grip not being made until the knife is clear of the upper bar2 thus the plaits or folds are made of irregular length4 ,illustration3 ,,improved ,,plaiting ,,machine4 ,to remedy this and to prevent its occurrence1 ,messrs4 ,a4 ,edmeston and ,sons1 ,manchester1 in the plaiting machines they are now manufacturing make the upper gripper bar movable as well as the table below4 ,referring to the illustration1 the upper gripper bars1 ,a ,a1 are capable of moving about the center pins1 ,b ,b1 and when the machine is working are operated in the following manner3 ,upon the shaft1 ,c1 which revolves in unison with the crank shaft working the plaiting levers and knife1 are placed two cams1 ,d1 one at each end1 inside the main frames4 ,these cams engage with and work two escapement levers or pallets1 ,e ,e1 upon which rest the feet of four rods1 attached one end to each of the upper gripper bars4 ,upon these four rods are helical springs of sufficient strength to hold down1 by means of the grippers to which they are connected1 the folds of cloth that have just been made4 ,the cam1 ,d1 is so shaped that when the advancing plaiting knife and cloth reach the front edge of the gripper bar1 the gripper is raised from the table to admit them freely4 ,the instant the end of the stroke is reached the anchor pallet or lever1 ,e1 escapes from the cam1 and the gripper bar is suddenly forced on to the knife and cloth by the springs before mentioned1 securely retaining the piece in its position4 ,simultaneously with the first of these motions the plaiting table itself is lowered1 and1 when the plaiting knife reaches the end of its stroke1 is released by means of the levers and chains1 ,f ,f1 which are in connection with the escapement pallets1 ,e1 and partake of their every motion4 ,these chains are so attached that they exert no effort upon the table until the escapement lever is moved1 thus permitting the plaiting table to press upward against either one or both of the gripper bars with the full force imparted to it by the weights and levers1 ,g ,g4 ,the chains1 furthermore1 are also threaded over pulleys in such a manner that they adjust themselves automatically to every position of the table and to the different thicknesses which the folded cloth acquires4 ,it will be obvious from this description that in plaiting there is no more strain put upon the cloth in placing it under the grip than is necessary to draw it over the table from the feed rollers4 ,this feature insures perfect immunity from the dragging out of grip1 as already described1 and renders the machine very useful for finishers and makers-up1 as the delicacy with which the cloth is handled prevents any damage being done to the finish of the lightest fabrics4 ,double cloth can1 of course1 be plaited by it equally well1 and the precision and uniformity with which the cloth is plaited makes the machine thoroughly reliable as a cloth measurer4--,tex4 ,manfr4 99 99 99 99 99 ,,self-,,acting ,,shuttle ,,guard4 ,illustration3 ,,self-,,acting ,,shuttle ,,guard4 ,the annexed illustration shows the essential parts of ,hahlo and ,liebreich's improvement1 the loom being now at work4 ,the handrail1 shuttle race1 and starting handle can be at once recognized1 and the shuttle guard will be seen in its proper position1 which position it rigidly retains as long as the loom is working1 but on a stoppage the rod swings back close underneath the handrail1 and quite clear of the reed4 ,the mode in which this is accomplished we will endeavor to make clear4 ,the guard is connected to the starting lever by the arrangement shown1 consisting of a stud on the handle1 on which1 with the movement of the slay1 lever1 a1 slides4 ,this lever1 by means of another lever and a link1 is attached to the shuttle guard by the crank1 b1 which1 by means of the set screw in the boss1 permits the shuttle guard to be adjusted in the most convenient place4 ,it will be observed that whenever the loom stops working1 whether it is stopped by hand or automatically1 the hand lever has to be moved1 and this movement is communicated to the shuttle guard by the mechanism just described1 placing the guard rod beneath the hand rail1 and leaving the whole of the shuttle race free and unencumbered4 ,the act of starting the loom brings the guard again to the working position without any extra act having to be performed by the weaver4 ,the action is entirely automatic1 and the weaver has not anything to do that she has not to do with the present unguarded looms4 ,the arrangement appeared to ourselves to be a very efficient one1 and it has the merit that the length of the guard can be made greater than the width of the cloth1 a further advantage that will be recognized by practical weavers4 99 99 99 99 99 ,,ruler ,,and ,,triangle ,,for ,,hatching4 ,the instrument shown in the cut is the invention of ,mr4 ,maginnis1 and is designed for producing equidistant hatchings4 ,it consists of a short ruler1 ,a1 and a triangle1 ,b1 supposed to be one of #de1 but which may be of any angle4 ,the triangle carries two stops1 c c1 while the ruler is provided with a conical piece1 ,d1 which is slotted1 and is held by a screw4 ,the play that occurs between this conical slide and the stops varies according to the position of the former4 ,illustration3 ,,ruler ,,and ,,triangle ,,for ,,hatching4 ,the apparatus operates as follows3 ,in the figure1 the stop to the right being in contact with the piece1 ,d1 a line is drawn along the right side of the triangle4 ,then the ruler is made to slide along the triangle until ,d touches the other stop1 and then the triangle is slid along the ruler until the stop to the right touches ,d again4 ,in this position another line is drawn1 and so on4 ,the position of the piece1 ,d1 between the stops is regulated according to the fineness of the hatching to be done4--,chronique ,industrielle4 99 99 99 99 99 ,,the ,,distillation ,,of ,,sea ,,water4 ,the supplying of the troops at ,suakim and in the ,soudan with water is one of the most important items in the whole conduct of the ,egyptian war4 ,even in cold or temperate latitudes fresh water is a first necessity for animal life2 much more is this the case in the desert2 and the wells in the country forming the scene of our military operations form in themselves valuable strategical points4 ,their supply1 however1 has to be supplemented1 and to do so artificial means and the aid of the engineer have to be enlisted into this service4 ,many of our readers see notices from time to time in the newspapers about this or that ship being employed1 or at least her steam fittings1 in distilling water for the use of the troops2 and although most of1 if not all1 our readers are engineers1 still it is no disparagement to some of them to assume that they are more or less unfamiliar with sea water distillation on the scale on which the process is now being carried on at ,suakim2 and as the subject is of general interest1 we give a short description of the process4 ,in a general sense1 fresh water is obtained from sea water by simply generating steam from the sea water1 passing the said steam through a surface condenser1 and filtering the resulting water4 ,the obtaining of fresh water in this way has been in practice on board sea-going ships for many years4 ,it is supposed by some authorities on this subject that the first time fresh water was thus obtained at sea was by an old captain of a brig which ran short of water1 and he cut up some pewter dishes into strips1 which he bent and soldered into a pipe4 ,he1 with the carpenter's aid1 fitted a wooden lid in one of the cooking boilers1 and fixed one end of his pipe in it4 ,he next sawed a water cask in half1 bored a hole in the bottom of one half1 and took his pipe through it1 filling the space round the pipe with sea water4 ,thus he extemporized a worm and still or condenser4 ,the distilled water1 however1 was scarcely drinkable4 ,not to be beaten1 however1 the captain got some pieces of charred wood which he put in the water1 which so far improved it as to render it at all events fit to sustain life1 and our skipper brought his brig and her screw safely to port4 ,what suggested the use of charcoal to his mind history does not tell4 ,for many years past scarce any sea-going vessel leaves port that is not fitted with a properly constructed distiller2 and one conspicuous advantage attending this practice is that each ship thus fitted to the satisfaction of the ,board of ,trade inspector is allowed to sail with only half the quantity of fresh water on board which she should have if not provided with a distiller4 ,the distiller and filter occupy very much less space than that which would be occupied by the casks or tanks of water otherwise required to be carried4 ,coming now a little to detail1 sea water distillers are usually fitted in connection with the winch and its boiler1 which latter supplies the steam both for distillation and to drive the engine working its circulating pump4 ,smaller distillers are worked without a pump1 the cooling water merely passing through by gravitation4 ,these smaller affairs again are of two kinds1 the one being mounted at one end of the cooking hearth1 as in outline sketch1 which shows a two oven hearth with distiller at one end4 ,a is the supply pipe to admit air to aerate the water2 ,b is the cock where fresh water is drawn off2 ,c is a pipe conveying cooling water to the condenser ,e1 placed on three little feet on top of the boiler1 ,f1 whose steam rises up a central pipe to the dome top1 where it expands out and returns downward through a number of tubes about #a in4 diameter1 in which it is condensed1 collected in a bottom chamber1 and drawn off through the cock1 ,b4 ,a distiller of this size would make about thirty gallons of fresh water per day4 ,very frequently a distiller1 such as is shown in the sketch1 is mounted separately1 and placed near the winch or donkey boiler1 which supplies it with steam1 the lower part1 ,f1 being then used as a filter4 ,the diameter of ,e is from #ae in4 to #ah in41 the outer casing being either iron or copper4 ,another form of distiller is one like the above1 but larger1 and having a small donkey engine and circulating pump attached thereto4 ,as a rule these distillers are vertical1 but larger apparatus are arranged horizontally4 ,to give our readers some general idea of size1 weight1 and produce of water1 we may say that a plain cylindrical distiller1 mounted on a square filter case1 measuring #c ft4 #i in4 high1 weighing #d cwt41 will distill twelve gallons per hour4 ,a larger size1 measuring #f ft4 #b in4 high1 and weighing about #bc cwt41 will give #he gallons2 while a still larger one1 measuring #g ft4 high and weighing #cb cwt41 yields #aej gallons4 ,these have no pumps4 ,when an engine and pump are fitted1 the weight is increased from about #hj per cent4 in the smaller to #ej per cent4 in the larger sizes4 ,an immense advantage attends the use of those distillers that are combined with a winch boiler4 ,of course1 the chief use of the winch is while in dock2 some use is made of it at sea to do heavy pulling and hauling1 to wash decks1 and in case of emergency the circulating pump is used as a fire engine4 ,were it not1 however1 for the distiller1 the winch boiler would simply be idle lumber at sea4 ,the distiller1 however1 finds useful employment for it1 and has also this excellent effect1 that as steam is pretty constantly kept up for the distiller1 in the evil event of a fire the boiler is ready to work at once4 ,in horizontal types of distiller an engine and pump are mounted on a cast iron casing as a bed1 and in this casing is placed a number of tubes through which the steam passes to be condensed1 the whole being simply a surface condenser with engine and pump above4 ,another type is that of a small single-flued horizontal boiler with combustion chamber and twenty or thirty return tubes--in fact1 the present high-pressure marine boiler on a small scale4 ,a boiler of this sort1 measuring #d ft4 to #e ft4 long1 #c ft4 #i in4 to #d ft4 #f in4 diameter1 would have a horizontal donkey engine on a bed at its side1 and at the end of the engine a vertical cylindrical condenser4 ,illustration ,few have done more1 perhaps none so much1 as ,dr4 ,normandy to make sea water distillation not only a success as a source of water supply1 but also to supply it at a minimum cost for fuel4 ,he by a peculiar arrangement of pipes embodied something of the regenerative system in his apparatus1 using the heat taken from one lot of steam to generate more1 and again the heat from this he used over again4 ,the defect of his older arrangements was undue complexity and consequent trouble to keep in order4 ,as can be well imagined1 the distillers in use at ,suakim are on a much more colossal scale1 and owing to the now almost universal use of surface condensers in ocean steamers1 no great difficulty ought to attend the adaptation of the boilers and condensers of one of our transports4 ,one of these full-powered steamers will indicate1 say1 #e1jjj horse-power1 and assuming her engines to use #be lb4 of steam per indicated horse-power1 or #b gallons1 she could distill some #ab1jjj gallons of water per hour4 ,as no appreciable pressure of steam need be maintained1 the boilers would suffer little from deposit1 especially if regularly blown out4 ,hard firing need not be resorted to2 indeed1 it would be injudicious1 as1 of course1 priming must be carefully guarded against4 ,of course1 the salt water distilled will affect the working1 not exactly of the distillers1 but of the boilers4 ,if the water in the harbor1 as is not improbable1 is muddy1 some method of filtering it before pumping it into the boilers ought1 if at all practicable1 to be resorted to1 for the twofold reason of preserving the boiler plates from muddy deposit1 and also to prevent priming1 which would certainly ensue from the use of muddy water4 ,no doubt the medical staff take care that the distilled water is alike thoroughly aerated and efficiently filtered4 ,the most successful method of aerating is1 we believe1 to cause the current of steam as it enters the condenser to suck in air by induced current along with it4 ,the filtering ought not to present any difficulty1 as at all events sand enough can be had4 ,charcoal1 however1 is another affair1 and all distilled water ought to be brought into contact with this substance4 ,simple1 however1 as such an arrangement as this appears to be1 practical difficulties1 which it is said are insurmountable1 stand in the way of its adoption1 and the distilled water produced for ,egypt is made in special apparatus1 and various forms of condenser are employed1 made under various patents4 ,the principle involved is1 however1 in all cases the same4 ,steam is generated in one of the ships' boilers1 and condensed1 filtered1 and aerated in a special apparatus4 ,the great objection to the use of the ordinary surface condenser is that the main engines would1 in the majority of cases1 have to be kept going1 in order to pump the distilled water out of the condenser1 and to supply circulating water4 ,but it is easy to see that if engineers thought proper1 this difficulty could be readily got over4 ,separate circulating pumps1 usually centrifugal1 are now freely used1 and the addition of a special pump for lifting the condensed water presents no difficulty whatever4 ,while the main engines are running1 the withdrawal of much condensed water would no doubt risk the safety of the boiler2 but in the case of so-called distilling ships1 there need be no trouble incurred on this score4--,the ,engineer4 99 99 99 99 99 ,,aids ,,to ,,correct ,,exposure ,,on ,,photographic ,,plates4 ,footnote3 ,we take from the ,br4 ,jour4 of ,photo4 the following interesting paper read by ,w4 ,goodwin before the ,glasgow and ,west of ,scotland ,amateur ,association4 ,with good plates1 and intelligent development1 a practiced photographer may within certain limits correct the effects of an over or under exposure2 but you have all1 doubtless1 found out that there is a correct exposure1 and that you cannot trespass very far on either side of it without sacrificing something in the resulting negative4 ,,mr4 ,w4,k4 ,,burton',s ,,table ,,of ,,comparative ,,exposures ---------------------------------------- ------------------------------------ ,badly lighted ,portraits in bright interiors1 diffused light ,aperture ------------ up out of doors4 calculated ,landscape with ,fairly to _/ on the heavy foliage in lighted _/ ,portraits in standard foreground4 interiors _/ studio light system ------------- ------ _/ of the ,sea ,open ,under _/ ,portraits ,photographic and land- trees1 in ordinary ,society4 sky4 scape4 up to room4 ---------------------------------------- ------------------------ sec sec sec m s m s h m sec m s m s ,no4 #a1 #a_/afj #a_/ej #a_/h #j #aj #j #aj #j #b #a_/f #j #a #j #d or f_/#d ---------------------------------------- ------------------------ ,no4 #b1 #a_/hj #a_/be #a_/d #j #bj #j #bj #j #d #a_/c #j #b #j #h or f_/#e4feg ---------------------------------------- ------------------------ ,no4 #d1 #a_/dj #a_/ab #a_/b #j #dj #j #dj #j #h #b_/c #j #d #j #af or f_/#h ---------------------------------------- ------------------------ ,no4 #h1 #a_/bj #a_/f #a #a #bj #a #bj #j #af #a-a_/c #j #h #j #cb or f_/#aa4cad ---------------------------------------- ------------------------ ,no4 #af1 #a_/aj #a_/c #b #b #dj #b #dj #j #cb #b-b_/c #j #af #a #d or f_/#af ---------------------------------------- ------------------------ ,no4 #cb1 #a_/e #b_/c #d #e #bj #e #bj #a #d #e-a_/c #j #cb #b #h or f_/#bb4fbg ---------------------------------------- ------------------------ ,no4 #fd1 #b_/e #a-a_/c #h #aj #dj #aj #dj #b #h #aj-a_/b #a #d #d #ae or f_/#cb ---------------------------------------- ------------------------ ,no4 #abh1 #d_/e #b-b_/c #af #ba #j #ba #j #d #ae #ba #b #h #h #cj or f_/#de4bee ---------------------------------------- ------------------------ ,no4 #bef1 #a-a_/b #e-a_/b #cb #db #j #db #j #h #cj #db #d #aeag #j or f_/#fd ---------------------------------------- ------------------------ ,the estimation of this correct exposure is probably the greatest difficulty in photography1 and it is particularly discouraging to find plate after plate useless because the guess has been wide of the mark4 ,there are some here to-night who have spoiled so many plates that at last they are prepared by experience for almost any contingency1 and to those ,i nave very little to say2 but there are also many who are still in their troubles1 and ,i propose to tell them how the amount of guesswork required may be reduced to a minimum4 ,the factors which govern exposure are3 the subject of the picture1 the lens and its aperture1 the rapidity of the plate1 and last1 but not by any means least1 the quality of the light by which the work is to be done4 ,let us consider each of these separately1 and see if we cannot reduce any of them to rule4 ,in this respect the subject will be found somewhat intractable4 ,scarcely two subjects will be found to send exactly the same amount of light through the lens4 ,however1 a broad classification may be made1 and this has been done by ,mr4 ,burton in his ,table of ,comparative ,exposures4 ,a glance at this table will show how greatly the character of the view may influence the time of exposure4 ,thus1 with full aperture of a rapid symmetrical1 the exposure for open landscape is given as one-twelfth of a second2 when heavy foliage appears in the foreground1 half a second will be required2 while1 under trees1 as much as forty seconds may be needed4 ,the first aid ,i have to suggest is the use of such a table as ,mr4 ,burton's4 ,before we do anything more in this direction1 we must consider the influence of the lens and its diaphragms4 ,in theory the single landscape lens is more rapid than the doublet of equal aperture1 but the difference is so little that it may be disregarded in practice1 and my remarks will apply to both4 ,the rapidity of a lens depends mainly on its aperture and its focal length4 ,thus a lens of twelve inches focus will require four times the exposure of a six inch1 with an equal sized diaphragm1 and a quarter inch diaphragm will require four times the exposure of a half inch when used in the same lens4 ,the ,photographic ,society of ,great ,britain have recommended that the diaphragms of all lenses should bear such relation to the focal length that each should require exactly double the exposure of the next smaller4 ,now1 if we turn again to ,mr4 ,burton's table1 we shall find that it is constructed on this principle1 and that each stop is numbered so as to show its exposure4 ,obviously1 the most sensible thing would be to get a set of stops made to correspond with this arrangement1 but we will see how we can construct a table for stops of any size4 ,first1 if possible1 find the equivalent focus of your lens4 ,if it is made by a known maker1 you will find it in his price list1 and if not1 you may calculate it for yourself by the rules given in the various text books1 provided you have a camera of pretty long focus4 ,however1 it will be near enough for our purpose if you get a sharp image of the sun on a piece of paper1 and while you hold lens and paper1 get some one to measure the distance from the paper to the diaphragm aperture1 or1 in the case of a single lens1 to the center of the lens4 ,note down this focal length1 and proceed to measure your diaphragms in sixteenths of an inch4 ,then1 with pen and paper1 proceed to divide the diameter of each stop into the focus1 and state the result as a fraction of the focus1 thus f_/#h4 ,for example1 a ,ross half plate rapid symmetrical has a focal length of #g in42 for convenience reduce this to sixteenths#abj4 ,a diaphragm measuring seven sixteenths will give the fraction f_/#ag4 ,now let us see if any of these stops correspond with ,mr4 ,burton's4 ,the first two in his table will only be found in portrait lenses1 but we shall probably find one to correspond with the third1 if we are using a doublet lens2 with a single lens we won't find any so large4 ,having picked out those that correspond1 and filled in the exposure for them1 we have now to deal with the odd sizes4 ,here is one1 f_/#bg1 which is just half way between ,no4 #af and ,no4 #cb1 but a moment's thought will show that as the exposure increases as the square of the diameter1 it won't do to take the exposure half way between the two4 ,we have another factor to consider now3 that is1 the rapidity of the plate4 ,if you use plates by a maker who has a name to sustain1 you may be pretty confident that they are of fairly uniform rapidity1 so after you have got into the way of working any particular brand1 the best thing you can do is to stick to it4 ,the exposures in our table are for plates of medium rapidity in good spring light4 ,in my own experience ,i find that they just suit thirty times plates1 or fifteen on the sensitometer2 but then ,i like a full exposure with slow development1 and ,i know that others find these exposures just right for twenty times plates developed in the usual way4 ,the most rapid plates in the market will not be overdone with half the given exposures4 ,it must always be borne in mind that an error of a fraction of a second in either direction may be corrected in development1 and it is impossible to make a very serious error if you refer to the table4 ,we come now to the light4 ,if you depend on the eye entirely in judging the quality of the light1 it will sometimes play you tricks4 ,the rays which are most active on the plates are those which have the least effect on the eye4 ,we can1 however1 by chemical means arrive at an exact estimate of the active power1 and for this purpose an actinometer is used4 ,this is simply an arrangement whereby a piece of sensitized paper is exposed and allowed to darken to a standard tint1 and by the time it takes to reach that tint the value of the light is judged4 ,capt4 ,abney has1 however1 pointed out that ordinary sensitized paper is not suitable for bromide plates1 since there are conditions of light in which the plates will be fairly rapid while the paper will be very slow4 ,he gives a formula for a bromide paper1 which is treated with tannin in order to absorb the bromine set free during exposure1 otherwise the darkening would be very slight4 ,i used this paper for a while1 but found it rather slow4 ,the tannin also turned brown on keeping for a week or so4 ,i then made some more1 substituting for tannin potassium nitrite 7not nitrate71 which is colorless4 ,this was an improvement1 but still it was just slow enough4 ,however1 noticing in ,capt4 ,abney's article the statement that the bromide of silver should be as nearly as possible in the same state in the paper as in the plate1 ,i thought ,why not ,morgan's paper8 ,this1 of course1 is just bromide emulsion on paper1 and if1 as ,i suspect from its color1 it contains a trace of iodide1 why1 so do most commercial plates4 ,a sheet of this paper cut into strips1 soaked for ten minutes in a fifteen-grain solution of potassium nitrite1 and dried1 gives a sensitive paper which darkens with great rapidity to a good deep tint1 and keeps indefinitely4 ,here is some prepared last summer1 which is still quite good4 ,to use this paper make a little box so that a little roll of it can be stored in one end1 and drawn forward as required beneath a piece of glass4 ,bearing in mind that your table of exposures is calculated for the best spring light1 go to the country some bright day next month with note-book1 actinometer1 and the necessary appliances for exposing a few plates4 ,select1 say1 an open landscape1 and use your smallest stop4 ,when all ready to expose1 get out your actinometer and expose it to the reflected light of the sky for ten seconds 7if the sun is shining1 turn your back to it1 and keep the actinometer in your own shadow72 then put it in your pocket1 expose a plate according to your table1 and in case the light or plate should not be just in accordance with the conditions under which the table was prepared1 expose other two plates1 one a little less and one a little more than that first exposed4 ,then note down everything you have done--kind of view1 stop1 speed of plate1 exposure of each plate1 and length of exposure of actinometer4 ,when you get home1 the first thing to do is to get hold of a paint box and paint the underside of the glass of your actinometer to match the darkened paper4 ,do this by gas light4 ,then scrape away a little of the paint1 so as to let a strip of the paper be seen below it4 ,after this develop your three plates with a developer of normal strength1 and see which is best4 ,if you have chosen a really bright spring day1 and are using plates of medium rapidity1 you will most likely find that exposed according to the table just about right4 ,now let us see how we can use these aids in our field work4 ,we have ascertained the correct exposure with a given stop on one class of view1 with light of a given quality1 but now suppose all these conditions altered4 ,let the view have heavy foliage coming close up to the camera1 the stop be a size larger than that used in our first experiment1 and the day rather dull4 ,the table tells us what the exposure would be with this stop on this view1 on a bright day2 and if the actinometer take twenty seconds to reach the painted tint1 then we must double the exposure given in the table4 ,you may sometimes find that the actinometer indicates a very different exposure from what the eye would lead you to expect4 ,for instance1 one day last ,september ,i went to ,bothwell ,castle1 to get a picture ,i knew of in the grounds4 ,it was one of those strange yellow days we had then1 and the sun1 though shining with all his might1 was apparently shining through orange glass4 ,the actinometer indicated an exposure of thirty seconds where in good light one would be right4 ,i was rather incredulous4 ,thirty seconds in broad sunshine6 ,however1 ,i gave this exposure1 but for my own satisfaction ,i gave another plate fifteen seconds only4 ,on developing1 the latter was hopelessly underexposed while that having thirty seconds gave a negative which furnished one of my exhibition pictures4 ,i have shown you how to reduce the quality of the light to a certainty1 also how to reduce to rule the exposure with different lenses and stops on certain classes of subjects1 and it remains with you only to guess correctly to what class the view you wish to take belongs2 ,i can assure you from my own experience that there is enough uncertainty about that point to prevent good negatives ever becoming monotonous4 ,the only aid ,i can suggest in this case is the continual use of a note-book4 ,note every plate you expose1 and when you have a failure be careful to record the fact1 and you will gradually find these accumulated notes becoming a great help in cases of doubt4 ,one hint ,i can give to beginners is that a great number of the pictures to be met with in this part of the country are intermediate between ,open ,landscape and ,landscape with heavy foliage in foreground2 and it is scarcely needful to say that if you are in doubt1 let the exposure be rather too much than too little2 you may make a negative of an overexposed plate1 but never of an underexposed one4 99 99 99 99 99 ,,isochromatic ,,photography4 ,footnote3 ,read at the stated meeting of the ,franklin ,institute1 ,march #ah1 #ahhe4 ,by ,,fred4 ,e4 ,,ives4 ,it is well known that the ordinary photographic processes do not reproduce colors in the true proportion of their brightness4 ,violet and blue photograph too light2 green1 yellow1 orange and red1 too dark4 ,for a long time it was believed to be impossible to remedy this defect2 and even when it became known that bromide of silver could be made more sensitive to yellow and red by staining it with certain dyes1 the subject received very little attention1 because it was also known that the increase of sensitiveness was too slight to be of practical value in commercial photography4 ,dr4 ,h4,w4 ,vogel1 who was one of the first1 though not the first1 to devote attention to this subject1 announced1 in #ahgc1 that he had succeeded in making a yellow object photograph lighter than a blue or violet one1 by using a silver-bromide plate stained with coraline1 and exposed through a yellow glass4 ,the plate showed no increased sensitiveness to red1 and the experiment1 although of considerable scientific interest1 did not indicate a practically useful process4 ,in the spring of #ahgh ,i became interested in this subject1 and tried to discover a method of producing plates which should be sensitive to all colors1 and capable of reproducing them in the true proportion of their brightness4 ,i commenced by trying nearly all the color sensitizers which had already been suggested1 in order to learn which was the best1 and then1 if possible1 why it was the best1 as a guide to further research4 ,chlorophyl was the only thing ,i tried which was sufficiently sensitive to red to offer any encouragement in that direction2 but the solution which ,i obtained was weak and unstable1 and far from being a satisfactory color sensitizer4 ,hoping to obtain a better solution with which to continue my experiments1 ,i made extracts from many kinds of leaves1 and found that a solution from blue myrtle leaves looked better and kept better than any other1 and when it was applied to the silver-bromide plates they became remarkably sensitive1 not only to all shades of red1 but also to orange1 yellow1 and green4 ,by placing in front of the lens a color-screen consisting of a small glass tank containing a weak solution of bichromate of potash1 to cut off part of the blue and violet light1 ,i obtained1 with these chlorophyl plates1 the first photographs in which all colors were reproduced in the true proportions of their brightness4 ,but my chief desire at that time was to realize a method of producing from any object in colors a set of three negatives1 in one of which the shadows should represent the blue of the original1 in another the yellow1 and in another the red1 in such a manner that transparent pigment prints from these negatives--blue1 yellow1 and red--would1 when superimposed on a white surface1 represent not only the lights and shadows1 but also the colors of the object4 ,this had already been attempted by others1 who failed because their plates were not sufficiently sensitive to red and yellow4 ,having succeeded perfectly in my undertakings1 ,i published my discovery in #ahgi1a explaining how to prepare and use the chlorophyl plates1 in connection with the yellow screen1 for the purpose of securing correct photographs of colored objects4#b ,footnote #a3 ,philadelphia ,photographer1 ,december1 #ahgi1 p4 #cfe4 ,footnote #b3 ,i intended this publication to be a very full and explicit one1 and it was sufficiently so to be perfectly understood by most who saw it2 but some may think ,i did not sufficiently emphasize the importance of using the particular kind of chlorophyl which ,i mentioned4 ,in a brief communication to the editor of the ,photo4 ,news1 in #ahhc1 ,i described some experiments with eosine as a color sensitizer1 and then called attention to the superiority of blue-myrtle chlorophyl for this purpose1 stating that ,i had not been able to secure such results with any other kind of chlorophyl1 and that a fresh solution from fresh leaves must be used to secure the greatest possible degree of sensitiveness4 ,see ,photo4 ,news1 ,nov4 #ahhc1 p4 #gdg4 ,so far as ,i know1 nobody tried the process4 ,nearly five years later ,dr4 ,vogel announced that1 after eleven years of investigation1 he had at last realized a successful process of this character1 and that this new process of his was the solution of a problem that had long been encompassed with difficulty4 ,this publication attracted a great deal of attention1 and gave me occasion to again call attention to my process1#c and point out that it was not only the first practical solution of this problem1 but the only truly isochromatic process ever discovered4 ,dr4 ,vogel's new process was not only no better in any respect1 but the plates were insensitive to scarlet and ruby-red1 and therefore would not photograph all colors in the true proportion of their brightness4 ,footnote #c3 ,photo4 ,news1 ,london1 ,september #e1 #ahhd1 p4 #eff1 and ,year ,book of ,photography for #ahhe1 p4 #aaa4 ,my method consists in treating ordinary collodio-bromide emulsion plates with blue myrtle chlorophyl solution1 exposing them through the yellow screen1 and then developing them in the usual manner4 ,the emulsion which ,i have employed is made with an excess of nitrate of silver1 which is afterward neutralized by the addition of chloride of cobalt2 it is known as ,newton's emulsion4 ,i now prepare the chlorophyl from fresh blue myrtle leaves1 by cutting them up fine1 covering with pure alcohol1 and heating moderately hot2 the leaves are left in the solution1 and some zinc powder is added1 which helps to keep the chlorophyl from spoiling4 ,i have a bottle of this solution which was prepared about six months ago1 and now appears to be as good as when first made4#d ,a glass plate is flowed with the emulsion1 and as soon as it has set1 the chlorophyl solution is applied for a few seconds1 after which the plate is washed in pure water until smooth1 when it is ready for exposure4 ,footnote #d3 ,i originally recommended chlorophyl extracted from dried leaves1 because ,i had not yet learned how to preserve the solution for more than a few weeks2 and at some seasons it would be difficult1 if not impossible1 to obtain fresh leaves4 ,the tea organifier which ,i recommended is also a color sensitizer1 and when it is used in connection with the chlorophyl from dried leaves the plates are as sensitive to red as can be safely prepared and developed in the light of an ordinary photographic dark-room4 ,plates prepared with chlorophyl from fresh leaves do not require treatment with the tea organifier to secure this degree of sensitiveness4 ,recently ,i have used the tea organifier and some other sensitizers1 in connection with the solution from fresh myrtle-leaves1 and in this way have produced plates having such an exalted color sensitiveness as to be unmanageable in ordinary dark-room light4 ,possibly1 such plates might be prepared and developed in total darkness1 by the aid of suitable mechanical contrivances1 but ,i am not sure that they would work clear even then1 because they appear to be sensitive to heat as well as to light4 ,my color-screen consists of a small plate-glass tank1 having a space of #c_/af of of an inch between the glass1 filled with a solution of bichromate of potash about one grain strong4 ,i place the tank in front of the lens1 in contact with the lens-mount4 ,the advantage of this tank and solution is that it can be more easily obtained than yellow plate glass1 and the color can be adjusted to meet any requirement4 ,the plates require about three times as much exposure through the yellow screen as without it1 and may be developed with the ordinary alkaline pyro-developer4 ,illustration3 ,,ives' ,,process ,,of ,,isochromatic ,,photography4 ,in order to illustrate the value of this process1 ,i made two photographs of a highly-colored chromo-lithograph1 representing a lady with a bright scarlet hat and purple feather1 a yellow-brown cape and a dark-blue dress4 ,one1 by the ordinary process1 represents the blue as lighter than the yellow-brown1 the bright scarlet hat as black1 and the purple feather as nearly white4 ,the other1 by the chlorophyl process1 reproduces all colors in nearly the true proportion of their brightness1 but with a slight exaggeration of contrast produced purposely by using a too-strong color solution in the small tank4 ,i also made two landscape photographs1 one by the ordinary process1 and the other by the chlorophyl process1 exposing them simultaneously4 ,in the ordinary photograph1 distant hills are lost through overexposure1 yet the foreground seems underexposed1 and yellow straw-stacks and bright autumn leaves appear black4 ,in the chlorophyl photograph1 the distant hills are not overexposed1 nor is the foreground underexposed2 the yellow straw-stacks appear nearly white1 and bright autumn leaves contrast strongly with the dark green about them4 ,to test the relative color-sensitiveness of plain emulsion plates1 plates stained with eosine1 and plates stained with the blue-myrtle chlorophyl1 ,i exposed one of each kind through the same yellow screen1 giving each five minutes exposure1 on the same piece of copy1 which was the chromo-lithograph already described4 ,the plain emulsion plate showed only the high lights of the picture1 after prolonged development4 ,the eosine plate was underexposed1 but brought up everything fairly well except the scarlet hat1 which came up like black4 ,the chlorophyl plate was overexposed1 brought out all colors better than the eosine plate1 and gave full value to the bright scarlet of the hat1 the detail in which was beautifully rendered4 ,dr4 ,vogel advanced the theory that silver-bromide is insensitive to yellow and red1 because it reflects or transmits those colors2 and that it becomes sensitive when stained1 because of the optical properties of the dyes4 ,he afterward admitted that only such dyes as are capable of entering into chemical combination with the silver-bromide proved capable of increasing its sensitiveness to color1 but he held to the theory that the optical properties of the compound were the cause of its color-sensitiveness4 ,i have shown that the color-sensitiveness can be produced by treatment with an organic compound which has none of the optical properties characteristic of dyes2 and that chlorophyl1 which absorbs only red light1 greatly increases the sensitiveness also to yellow and green4 ,there is1 therefore1 good reason to doubt if the color-sensitiveness is ever due to the optical properties of the dye or combination4 ,attempts have been made to produce isochromatic gelatine dry plates which1 while many times more sensitive to white light than my chlorophyl plates1 shall also show the same relative color-sensitiveness4 ,such plates would be very valuable but for one fact3 it would be necessary to prepare and develop them in almost total darkness4 ,gelatine bromide dry plates extremely sensitive to yellow1 but comparatively insensitive to red1 might be used to advantage in portrait and instantaneous photography1 because they could be safely prepared and developed in red light2 but when truly isochromatic photographs are required1 the time of exposure must be regulated to suit the degree of sensitiveness to red1 which cannot safely be made greater than ,i have realized with my chlorophyl process4 99 99 99 99 99 ,,distortion ,,from ,,expansion ,,of ,,the ,,paper ,,in ,,photography4 ,the effect of the unequal expansion of paper1 when wetted1 in causing distortion of the photographic image impressed upon it1 has1 in the case of ordinary photographs upon albumenized paper1 been well recognized2 but the extent to which such distortion may exist under different treatment is worthy of some special consideration1 particularly with reference to the method of printing upon gelatinized paper1 which has been thought by some likely to supersede the method now usually employed with albumenized paper4 ,when a print upon the ordinary photographic 7albumen7 paper is wetted1 the fiber expands more in one direction than in the other1 so that the print becomes unequally enlarged1 very slightly in one and much more so in the other way of the paper4 ,when the paper is dried without any strain being put upon it1 the fibers regain very nearly their original dimensions and position1 so that the distortion which has existed in the wet condition nearly disappears4 ,if the photograph is cemented1 while in the expanded condition1 upon a rigid surface1 the distortion then existing is fixed1 and rendered permanent4 ,such a cementation or method of mounting is that which has been generally adopted1 and the consequence has been that every now and then complaints have justly been made of the untruthfulness--owing to this particular distortion--of photographs2 productions whose chief merit has often been asserted to consist in their absolute truthfulness4 ,this distortion is very manifest when1 in a set of portraits1 some of the prints happen to have been made in one direction of the paper1 and others with the long grain the other way4 ,i have known a case where a proof happened to increase the face in width1 and all the other prints increased it in length4 ,of course1 neither was correct1 but the proof had been accepted and liked1 and the remainder of the set had to be reprinted with the grain of the paper running in the same direction as that in the first one which had been supplied4 ,another evil arising from mounting prints while expanded with moisture is1 that in drying the contraction of the paper pulls round the card into a curved form and although by rolling this curvature may be temporarily got rid of1 the fiber of the paper is in a strained condition1 and the bent state of the mount is1 sooner or later1 renewed thereby4 ,to remedy these evils it has been proposed to mount the print when dry1 by forcible pressure against a slightly damped card1 the back of the print having been previously coated with a cement and dried4 ,this plan is1 to a great extent1 successful2 but that it does not give absolute immunity from distortion is1 ,i think1 evident from the following consideration4 ,the prints1 after being mounted a few days1 will show a certain tendency to curl inward4 ,this curling1 ,i take it1 is a measure of the strain upon the print1 produced by the more complete return to its original dimensions of the paper photograph4 ,probably it would be well to keep the prints a few days after drying1 or to subject them to alternations of damp and dryness1 in order to facilitate this complete return before being placed upon the card4 ,the evil of distortion is1 however1 very slight--perhaps imperceptible--compared with that existing when the prints are mounted wet4 ,i may mention1 en passant1 that ,i have found gum much more satisfactory as a mountant than starch paste in what is known as the dry mounting system4 ,the paper which has recently been introduced for producing prints by development upon a gelatine surface does not generally1 when dried in the usual way1 give so good or so brilliant a surface as that of albumenized paper2 but on the other hand it is very easy with it to obtain what is called an enamel surface1 by simply allowing it to dry in contact with a prepared surface of glass4 ,this method of finishing has therefore been much recommended and adopted1 but without consideration of the effect of distortion in connection with it4 ,in an ordinary photograph the print is mounted damp1 but in the case of a print squeegeed on to the glass1 the paper is saturated and thoroughly swollen1 and the use of the squeegee strains it out to its fullest extent4 ,by drying in the position in which it has been held by contact with the glass1 the distortion becomes fixed1 and if the print is mounted while in this state the distortion is made permanent4 ,how long the strain and distortion remain in an unmounted print1 and whether by time and alternations of moisture and dryness the strain would be lost1 and if so1 whether the brilliant enamel surface would go at the same time1 are questions worthy of further investigation and discussion4 ,for mounting prints upon developed gelatine paper1 it has been recommended to cement the edges only1 so as to leave the greater part of the print with its enamel surface4 ,this plan is unsatisfactory1 for two reasons1 besides the objection on the ground of distortion4 ,there is a rough-looking margin which spoils the continuity of appearance1 especially 7as in the specimens ,i have seen7 where the line of cement is not kept at an exact width1 but encroaches here and there4 ,secondly1 the print1 from not being attached to the mount all over1 is apt1 especially when in a large size1 to be somewhat wavy and wanting in flatness4 ,another plan recommended1 as giving a surface resembling albumen paper1 is to paste the back of the print without moistening the surface1 and so mount4 ,some prints that have been shown thus treated had so strongly curled the cards upon which they were mounted that it is evident there was considerable strain and consequent distortion4 ,a third plan recommended is to paste the back of the print while in contact with the glass upon which it has to dry2 and1 when dried1 to mount by passing through a rolling press with a damped card4 ,this plan looks1 at first sight1 like that recommended for albumen paper1 and called dry mounting4 ,consideration1 however1 will show that there is a radical difference4 ,in the case of the albumen paper the print has been dried without strain1 and therefore but little change is to be looked for1 while the print dried in contact with glass is strained to the utmost1 causing present distortion and future curling of the mount4 ,perhaps the evil of distortion caused by enameling may be reduced to a minimum by soaking the print in alcohol previous to laying it upon the glass4 ,since the distortion of the photograph arises from the unequal expansion of the paper when wet1 it becomes a question whether something may not be done in the selection of the paper itself4 ,it may be that some makes vary much less than others in the length against width extension of the surface by wetting4 ,it must be remembered that for gelatine emulsion we are not nearly so limited in the selection of paper as when it is required to be albumenized4 ,in the latter case the image is in the paper1 whereas with gelatine the image is contained in the surface coating4 ,i may mention that the best plain1 i4e41 not enameled1 but resembling that of ordinary albumen paper1 surface that ,i have seen upon gelatine paper was upon some foreign post that ,i had obtained for another purpose4 ,the emulsion employed was that described by ,mr4 ,j4,b4,b4 ,wellington1 and this gentleman agreed with me in attributing the superiority of the surface obtained to the fine quality of the paper upon which the emulsion had been coated4 ,some commercial samples appear to be coated upon paper of somewhat coarse texture4 ,this does not show when the print is enameled4 ,the unequal expansion of paper is a subject of interest1 not only in connection with gelatine paper for development1 but with various photographic processes4 ,in making carbon transparencies for instance1 the gelatine film which is squeegeed against the glass necessarily takes its dimensions from the paper to which it is attached1 and if that be expanded more in the one direction than another1 the transparency is similarly deformed2 and so1 of course1 is any negative1 enlarged or otherwise1 produced in the camera therefrom4 ,a reproduced negative by contact printing may either have the distortion due to expansion of the paper bearing the gelatine film removed or doubled1 according to the direction in which the paper is used for the new negative4--,w4,e4 ,debenham1 in ,br4 ,jour4 of ,photography4 99 99 99 99 99 ,,measuring ,,the ,,thickness ,,of ,,boiler ,,plates4 ,an ingenious process for determining the thickness of iron plates in boilers1 or places where they cannot otherwise be measured without cutting them1 has been invented by ,m4 ,lebasteur4 ,he spreads upon the plate the thickness of which he desires to find1 and also upon a piece of sheet iron of known thickness1 a layer of tallow about #j4ja inch thick4 ,he then applies to each1 for the same length of time1 a small object1 such as a surgeon's cauterizing instrument1 heated as nearly as possible to a constant temperature4 ,the tallow melts1 and as in the thicker plate the heat of the cautery is conducted away more rapidly1 while in the thin plate the heat is less freely conducted away1 and the tallow is consequently melted over a large area1 the diameters of the circles of bare metal around the heated point1 bounded after cooling by a little ridge of tallow1 will be to each other inversely as the thickness of the plates4 ,the process is stated to have given in the inventor's hands1 results of great accuracy4 99 99 99 99 99 ,,groups ,,of ,,statuary ,,for ,,the ,,pediment ,,of ,,the ,,house ,,of ,,parliament ,,in ,,vienna4 ,the pediment of the central pavilion and the two side pavilions of the new ,house of ,parliament1 at ,vienna1 are to be ornamented with groups of statuary4 ,the group in the middle pediment represents the granting of the constitution by the ,emperor ,francis ,joseph1 and was executed by ,professor ,helmer4 ,illustration3 ,,statuary ,,for ,,the ,,vienna ,,house ,,of ,,parliament4--,,science ,,and ,,literature4 7,,group ,,to ,,the ,,left47 ,the pediment of the left wing is ornamented by a group representing ,justice1 and the pediment of the right wing by a group representing the ,home ,government4 ,johannes ,benk1 the well known ,austrian sculptor1 designed and executed the last mentioned group4 ,the two figures at the left hand end of this group represent ,science and ,literature1 and those at the right hand end1 ,industry and ,commerce4 ,the entire group consists of nine figures1 the middle figure being seated and the rest standing1 sitting1 and lying1 as the space in the pediment allows4 ,a seated female figure studying a papyrus roll represents ,science1 and the adjacent female figure1 resting one arm on the figure representing ,science1 and the other1 on a lyre1 represents ,literature or ,poetry4 ,industry is represented by a strong and powerful woman holding a hammer1 and the figure of ,mercury and the prow of a vessel represent ,commerce4 ,illustration3 ,,statuary ,,for ,,the ,,vienna ,,house ,,of ,,parliament4--,,industry ,,and ,,commerce4 7,,group ,,to ,,the ,,right47 ,the modulation and formation of each figure conform strictly to ,grecian models1 as does also the entire arrangement of the figures in the group2 and yet there is much of modern life in the figures1 especially in the faces1 in which the stereotyped ,grecian profile has not been adopted4 ,the attitudes of the figures are also freer and more easy than those of the ,grecian period4--,illustrirte ,zeitung4 99 99 99 99 99 ,,on ,,the ,,fritts ,,selenium ,,cells ,,and ,,batteries4 ,footnote3 ,paper read before the ,american ,association for the ,advancement of ,science1 at ,philadelphia1 ,sept1 #e1 #ahhd4 ,by ,c4,e4 ,,fritts1 #db ,nassau ,st41 ,new ,york1 ,n4,y4 ,in all previous cells1 so far as ,i am aware1 the two portions or parts of the selenium at which the current enters and leaves it have been in substantially the same electrical state or condition4 ,furthermore1 the paths of the current and of the light have been transverse to each other1 so that the two forces partially neutralize each other in their action upon the selenium4 ,lastly1 the current flows through not only the surface layer1 which is acted upon by the light1 but also the portion which is underneath1 and not affected thereby1 and which therefore detracts from the actual effect of the light upon the selenium at the surface4 ,my form of cell is a radical departure from all previous methods of employing selenium1 in all of these respects4 ,in the first place1 ,i form the selenium in very thin plates1 and polarize them1 so that the opposite faces have different electrical states or properties4 ,this ,i do by melting it upon a plate of metal with which it will form a chemical combination1 sufficient1 at least1 to cause the selenium to adhere and make a good electrical connection with it4 ,the other surface of the selenium is not so united or combined1 but is left in a free state1 and a conductor is subsequently applied over it by simple contact or pressure4 ,during the process of melting and crystallizing1 the selenium is compressed between the metal plate upon which it is melted and another plate of steel or other substance with which it will not combine4 ,thus by the simultaneous application and action of heat1 pressure1 chemical affinity1 and crystallization1 it is formed into a sheet of granular selenium1 uniformly polarized throughout1 and having its two surfaces in opposite phases as regards its molecular arrangement4 ,the non-adherent plate being removed after the cell has become cool1 ,i then cover that surface with a transparent conductor of electricity1 which may be a thin film of gold leaf4 ,platinum1 silver1 or other suitable material may also be employed4 ,the whole surface of the selenium is therefore covered with a good electrical conductor1 yet is practically bare to the light1 which passes through the conductor to the selenium underneath4#e ,my standard size of cell has about two by two and a half inches of surface1 with a thickness of #a_/ajjj to #e_/ajjj inch of selenium4 ,but the cells can1 of course1 be made of any size or form4 ,a great advantage of this arrangement consists in the fact that it enables me to apply the current and the light to the selenium in the same plane or general direction1 instead of transversely to each other as heretofore done1 so that ,i can cause the two influences to either coincide in direction and action1 or to act upon opposite faces of the selenium and oppose each other1 according to the effect desired4 ,footnote #e3 ,the method of constructing the cells was described in the ,,scientific ,,american ,,supplement1 ,no4 #dfb1 for ,nov4 #h1 #ahhd1 page #gcga4 ,by virtue of the process and arrangement described1 my cells have a number of remarkable properties1 among which are the following3 #a4 ,their sensitiveness to light is much greater than ever before known4 ,the most sensitive cell ever produced1 previous to my investigations1 was one made by ,dr4 ,werner ,siemens1 which was #ad4h times as conductive in sunlight as in dark4 ,in table ,a1 ,i give results obtained from a number of my cells4 ,it will be observed that ,i have produced one cell which was #ccg4e times as conductive in hazy sunlight as in dark4 ,the tremendous change of resistance involved in the expression #ccg4e times may perhaps be more fully realized by saying that #ii4gjd per cent4 of the resistance had disappeared temporarily1 under the joint action of light and electricity1 so that there remained less than #c_/aj of #a per cent4 of the original resistance of the selenium in dark4 ,in order to obtain these high results1 the cells must be protected from light when not in use4 ,the resistance is first measured while the cell is still in total darkness4 ,it is then exposed to sunlight and again measured4 ,it is also necessary to send the current in at the gold electrode or face1 as the cell is much less sensitive to light when the light acts upon one surface of the selenium and the current enters at the opposite surface4 ,when the two influences1 the light and the current1 act through the gold1 in conjunction1 their forces are united2 and1 as every atom of the selenium is affected by the light1 owing to the extreme thinness of the plate1 we have the full effect shown in the measurements4 ,,table ,a4 ,,sensitiveness ,,to ,,light4 ---------------------------------------- ------------------------- ,selenium ,battery ,resistance in ,resistance in cell4 power4 dark4 sunlight4 ,ratio4 ---------------------------------------- --------------------- ohms4 ohms4 ,no4 #bb #e elements4 #ci1jjj #cdj #aad to #a #bcfe #ad1jjj #agj #hb4c #bdge #fdh1jjj #b1djj #bgj #be #e #ahj1jjj #icj #aif4e #bf #e #ace1jjj #gaj #aij #ajg #e #aah1jjj #gdj #aei #ajh #e #bjj1jjj #ijj #bbb #abb #e #ef1jjj #bbj #bed4e #abife #bjj1jjj #idj #bab #acg #e #ajh1jjj #cbj #ccg4e ---------------------------------------- ------------------------- ,footnote #f3 ,cells ,no4 #bc and ,no4 #abi are now in possession of ,prof4 ,w4 ,gryllis ,adams1 of ,king's ,college1 ,london2 ,dr4 ,werner ,siemens has ,no4 #be1 and ,prof4 ,george ,f4 ,barker1 of ,philadelphia1 has ,no4 #bf4 ,footnote #g3 ,no4 #bd was measured with a bridge multiplier of #f to #a4 ,cells which are sensitive to light improve by being used daily1 and their sensitiveness becomes less if they are laid aside and not used for a considerable length of time1 especially if allowed to become overheated4 ,they should be kept cool1 and exposed to light frequently1 whether they are used or not4 ,mode of measuring cells4--,so great is the sensitiveness of these cells to external influences1 that it is necessary to adopt some particular system in measuring their resistance and to adhere strictly to that system1 as every change in the method of measurement produces a difference in the result1 and the different measurements would not be comparable with each other4 ,the reason for this will be explained presently4 ,the system ,i have adopted is the ,wheatstone's bridge arrangement1 with equal sides1 never using multipliers except for some experimental purpose4 ,in each multiplier wire ,i have #ejj ohms resistance4 ,when the bridge is balanced1 one-half of the current flows through the cell and acts upon the selenium4 ,between the bridge and the cell is a reversing switch1 so that the current can be reversed through the cell without changing its course through the bridge4 ,a ,bradley tangent galvanometer is used1 employing the coil of #afj ohms resistance4 ,the ,leclanche battery is exclusively used in measurements for comparison4 #b4 ,the kind of battery employed has a marked effect upon the sensitiveness to light1 which is largely reduced or entirely destroyed when the bichromate battery is used4 ,the same cells again become extremely sensitive with the ,leclanche battery4 ,we might expect that a change in the current employed would cause a change in the resistance of a cell1 but it is not clear how or why it should affect the sensitiveness of selenium to light4 ,if one kind of battery current destroys its sensitiveness1 may we not suppose that another kind might increase its sensitiveness8 ,although the ,leclanche has operated well1 some other may operate still better1 and by its special fitness for use on selenium cells may intensify their actions1 and so bring to light other properties yet unthought of4 ,is not here a promising field for experiment1 in testing the various forms of battery already known1 or even devising some new form especially adapted to the needs and peculiarities of selenium cells8 ,one year ago ,i made the foregoing suggestion in a paper on ,a ,new ,form of ,selenium ,cell1 presented before this ,association at ,minneapolis4 ,i am now at liberty to state that my photo-electric battery1 presently to be described1 marks an advance in the direction indicated4 ,the current from this battery increases the sensitiveness of the cells to light1 and also to reversal of current4 ,one cell whose highest ratio in light was about #hc to #a1 with the ,leclanche battery1 when measured with my battery gave a ratio of #abj to #a4 ,it seems to make the resistance of the cell both higher in dark and lower in sunlight than with the ,leclanche battery4 ,but the field is yet open to others1 for the discovery of a battery which may be still better for use with selenium cells4 #c4 ,the two surfaces of the selenium act differently toward currents sent into them from the contiguous conductors4 ,one surface offers a higher resistance to the current than the other4 ,the former ,i utilize as the anode surface1 as ,i have found that the cell is more sensitive to light when the current enters at that surface1 which is ordinarily the one covered by the gold or other transparent conductor4 ,some cells have this property but feebly developed2 but in one instance the resistance offered to the current by the anode surface was #bef times as high as that offered by the cathode surface to the same current4 ,in the majority of cases1 however1 the ratio does not exceed ten times4 ,table ,b gives some recent results4 ,,table ,b4 ,,sensitiveness ,,to ,,reversal ,,of ,,direction ,,of ,,current4 ---------------------------------------- ------------------------ ,resistance ,no4 of cell4 ,battery4 gold gold ,ratio anode4cathode4 ---------------------------------------- ----------------------- ohms4 ohms4 #c_/h inch square4 ,no4 #d #e elements4 #bj1jjj #a1jjj #bj to #a #c ,se4 cell4 #f1ejj #djj #af4b ,full size1 ,no4 #ac #a element4 #i1jjj #hjj #aa4b #ad #e #b1ddj #acj #ah #ae #e #d1fdj #baj #bb #bg #e #f1ijj #ddj #af #abf #a #e1jjj #ccj #ae ---------------------------------------- ----------------------- ,the direction of the current is always indicated by stating the position of the gold electrode1 by the terms gold anode and gold cathode4 ,the above measurements were made in dark4 #d4 ,sensitiveness to change of battery power4--,my cells are extremely sensitive to any change in the strength or character of the current flowing through them1 which is shown by a corresponding change in the resistance of the cell4 ,i can1 therefore1 vary the resistance of one of my cells in many ways1 and the following may be specified-- 7a7 ,by changing the potential or electromotive force of the current through the cell4 7b7 ,by changing the quantity of the battery or current4 7c7 ,by putting more or less resistance in the circuit4 7d7 ,by dividing the current1 by one or more branch circuits or shunts around the cell4 7e7 ,by varying the resistance in any or all of said circuits4 ,a cell whose resistance becomes greater as the battery power becomes greater1 and vice versa1 ,i call an ,l ,b cell signifying ,like the ,battery power4 ,a ,u ,b cell is one whose resistance becomes greater as the battery power 7or strength of current7 becomes less1 and vice versa1 being ,unlike the ,battery power1 or current strength4 ,these changes of resistance are not due to heating of the conductor or the selenium1 and the following instance will illustrate this4 ,i have one cell in which the selenium has about one-fourth inch square of surface melted on a brass block one inch thick4 ,this cell measured1 with #be elements of ,leclanche1 #dj1jjj ohms4 ,on changing the battery to #e elements the resistance fell instantly to #cj ohms1 and there remained4 ,on again using the current from #be elements1 the resistance instantly returned to #dj1jjj ohms4 ,had these results been due in any degree to heating1 the resistance would have changed gradually as the heat became communicated to the brass1 whereas no such change occurred1 the resistances being absolutely steady4 ,moreover1 even the fusion of the selenium would not produce any such change4 ,the ,u ,b property does not ordinarily change the resistance of the cell to exceed ten times1 i4e41 the resistance with a weak current will not be over ten times as high as with a strong one4 ,but ,i have developed the ,l ,b property to a far higher degree4 ,table ,c gives some recent results obtained with ,l ,b cells1 including one whose resistance1 with #be elements ,leclanche1 was #aa1cha times as high as with #h elements1 and which1 after standing steadily at #abc ohms 7and then at #cbe ohms with #a element71 on receiving the current from #be elements again returned to its previous figure of #a1djj1jjj ohms4 ,,table ,c4 ,,sensitiveness ,,to ,,change ,,of ,,battery ,,power4 ---------------------------------------- -------------------- ,resistance ,resistance ,no4 of cell4 with #be with #e ,ratio of elements4 elements4 ,change4 ---------------------------------------- -------------------- ohms4 ohms4 #c_/h inch square1 ,no4 #a #dj1jjj #cj #a1ccc to #a #c_/h #b #ac1jjj #dj #cbe #a_/d #a #a1djj1jjj #abch #aa1cha #a_/b #b #ejj1jjj #fb #h1jfd #a_/b #e #c1ejj #ba #afg ,full size1 ,no4 #ha #fh1jjj #aba #efa #hb #i1jjj #fd #adj #hc #ag1cjj #gd #bcc #aai #ce1fjj #ai #a1hid ---------------------------------------- -------------------- ,footnote #h3 ,this measurement was obtained with #h elements4 ,the results in the table were obtained by changing the strength of current by throwing in more or less of the battery4 ,like results can be obtained by varying the current through the cell by any of the other methods before specified4 ,the above measurements were in dark4 #e4 ,dual state of selenium4--,my cells1 when first made seem to have two states or conditions4 ,in one1 their resistance is very low1 in the other it is high4 ,when in the low state they are usually not very sensitive1 in any respect4 ,i therefore raise the resistance1 by sending an intermittent or an alternating current though the cells1 and in their new condition they at once become extremely sensitive to light1 currents1 and other influences4 ,in some cases they drop to the low state again1 and require to be again brought up1 until1 after a number of such treatments1 they remain in the sensitive state4 ,occasionally a cell will persist in remaining in the insensitive state4 ,the before mentioned treatment raises it up for a moment1 but1 before the bridge can be balanced and the resistance measured1 it again drops into the low or insensitive state4 ,some cells have been thus stimulated into the high or sensitive state repeatedly1 and every means used to make them stay there1 but without avail2 and they have had to be laid aside as intractable4 ,in the earlier stages of my investigations1 before the discovery of this dual state and the method of changing a cell from the insensitive to the sensitive condition1 hundreds of cells were made1 finished1 and tested1 only to be then ruthlessly destroyed and melted over1 under the impression that they were worthless4 ,now1 ,i consider nothing worthless1 but expect sooner or later to make every cell useful for one purpose or another4 ,the most singular part of this phenomenon is the wide difference in the resistance of the cells in the two states4 ,in the low state1 it may be a few ohms1 or even a few hundredths of an ohm4 ,in the high state1 it is the normal working resistance of the cell1 usually between #e1jjj and #bjj1jjj ohms1 but is often up among the millions4 ,the spectacle of a little selenium being stimulated1 by a few interruptions of the current through it1 into changing its resistance from a fraction of an ohm up to a million or several millions of ohms1 and repeatedly and instantly changing back and forth1 up and down1 through such a wide range1 we might almost say changing from zero to infinity1 and the reverse1 instantly1 is one which suggests some very far-reaching inquiries to the electrician and the physicist4 ,what is the nature of electrical conductivity or resistance1 and how is it so greatly and so suddenly changed8 #f4 ,radio-electric current generators4--,my cells can be so treated that will generate a current by simple exposure to light or heat4 ,the light1 for instance1 passes through the gold and acts upon its junction with the selenium1 developing an electromotive force which results in a current proceeding from the metal back1 through the external circuit1 to the gold in front1 thus forming a photo-electric dry pile or battery4 ,it should preferably be protected from overheating1 by an alum water cell or other well known means4 ,the current thus produced is radiant energy converted into electrical energy directly and without chemical action1 and flowing in the same direction as the original radiant energy1 which thus continues its course1 but through a new conducting medium suited to its present form4 ,this current is continuous1 constant1 and of considerable electromotive force4 ,a number of cells can be arranged in multiple arc or in series1 like any other battery4 ,the current appears instantly when the light is thrown upon the cell1 and ceases instantly when the light is shut off4 ,if the light is varied properly1 by any suitable means1 a telephonic or other corresponding current is produced1 which can be utilized by any suitable apparatus1 thus requiring no battery but the selenium cell itself4 ,the strength of the current varies with the amount of light on the cell1 and with the extent of the surface which is lighted4 ,i produce current not only by exposure to sunlight1 but also to dim diffused daylight1 to moonlight1 and even to lamplight4 ,i use this current for actual working purposes1 among others1 for measuring the resistance of other selenium cells1 with the usual ,wheatstone's bridge arrangement1 and for telephonic and similar purposes4 ,its use for photometric purposes and in current regulators will be mentioned further on4 ,it is undoubtedly available for all uses for which other battery currents are employed1 and ,i regard it as the most constant1 convenient1 lasting1 readily used1 and easily managed pile or battery of which ,i have any knowledge4 ,on the commercial scale1 it could be produced very cheaply1 and its use is attended by no expense1 inasmuch as no liquids or chemicals are used1 the whole cell being of solid metal with a glass in front1 for protection against moisture and dust4 ,it can be transported or carried around as easily and safely as an electro-magnet1 and as easily connected in a circuit for use wherever required4 ,the current1 if not wanted immediately1 can either be stored where produced1 in storage batteries of improved construction devised by me1 or transmitted over suitable conductors to a distance1 and there used1 or stored as usual till required4 #g4 ,singing and speaking cells4--,when a current of electricity flowing through one of my selenium cells is rapidly interrupted1 a sound is given out by the cell1 and that sound is the tone having the same number of air vibrations per second as the number of interruptions in the current4 ,the strength of the sound appears to be independent of the direction of the current through the cell4 ,it is produced on the face of the cell1 no sound being audible from the back of the cell4 ,an alternating current also produces a sound corresponding to the number of changes of direction4 ,experiments also show that1 if a telephonically undulating current is passed through the cell1 it will give out the speech or other sound corresponding to the undulations of the current--and1 furthermore1 that the cell will sing or speak in like manner1 without the use of a current1 if a suitably varied light is thrown upon it while in closed circuit4 ,my experiments having been devoted especially to those branches of the subject which promised to be more immediately practically valuable1 ,i have not pursued this inquiry very far1 and offer it for your consideration as being not only interesting1 but possibly worthy of full investigation4 ,,general ,,observations ,,on ,,the ,,properties ,,of ,,cells4 ,from the number of different properties possessed by my cells1 it might be anticipated that the different combinations of those properties would result in cells having every variety of action4 ,this is found to be the case4 ,as a general rule1 the cells are noteworthy in one respect only4 ,thus1 if a cell is extremely sensitive to light1 it may not be specially remarkable in other respects4 ,as a matter of fact1 however1 the cells most sensitive to the light are also ,u ,b cells4 ,the property of sensitiveness to light is independent of the power to generate current by exposure to light--the best current-generating cells being only very moderately sensitive to light1 and some of the most sensitive cells generate scarcely any current at all4 ,current-generating cells are1 almost without exception1 ,u ,b cells2 and the best current-generating cells are strongly polarized1 showing a considerable change of resistance by reversing the direction of a current through them2 and they are also strong anode cells1 i4e41 the surface next to the gold offers a higher resistance to a battery current than the other surface of the selenium does4 ,the power to generate a current is temporarily weakened by sending a battery current through the cell while exposed to light1 in either direction4 ,the current generated by exposure to light is also weakened by warming the cell1 unless the cell is arranged for producing current by exposure to heat4 ,the properties of sensitiveness to light and to change of battery power are independent of each other1 as ,i have cells which are sensitive to change of current but absolutely insensitive to light--their resistance remaining exactly the same whether the cells are in darkness or in sunlight4 ,i also have cells which are sensitive to light1 but are unaffected by change of battery power1 or by reversing the direction of the current through them4 ,the sensitiveness to change of battery power is also independent of the sensitiveness to reversal of direction of the current4 ,among the best ,l ,b cells1 some are anode cells and others are cathode cells1 while still others are absolutely insensitive to reversal of current or to the action of light4 ,constancy of the resistance4--,a noticeable point in my cells is the remarkable constancy of the resistance in sunlight4 ,allowing for differences in the temperature1 the currents1 and the light1 at different times1 the resistance of a cell in sunlight will remain practically constant during months of use and experiments1 although during that time the treatments received may have varied the resistance in dark hundreds of thousands of ohms--sometimes carrying it up1 and at others carrying it down again1 perhaps scores of times1 until it is matured1 or reaches the condition in which its resistance becomes constant4 ,as has already been stated1 the sensitiveness of a cell to light is increased by proper usage4 ,this increased sensitiveness is shown1 not by a lowered resistance in light1 but by an increased resistance in dark4 ,this change in the cells goes on1 more or less rapidly1 according as it is retarded or favored by the treatment it receives1 until a maximum is reached1 after which the resistance remains practically constant in both light and dark1 and the cell is then matured1 or finished4 ,the resistance in dark may now be #ej or even #ajj times as high as when the cell was first made1 yet1 whenever exposed to sunlight it promptly shows the same resistance that it did in the beginning4 ,the various treatments1 and even accidents1 through which it has passed in the mean time1 seem not to have stirred its molecular arrangement under the action of light1 but to have expended their forces in modifying the positions which the molecules must normally assume in darkness4 ,practical applications4--,there are many peculiarities of action occasionally found1 and the causes of such actions are not always discernible4 ,in practice1 ,i have been accustomed to find the peculiarities and weaknesses of each cell by trial1 developing its strongest properties and avoiding its weaknesses1 until1 when the cell is finished1 it has a definite and known character1 and is fitted for certain uses and a certain line of treatment1 which should not be departed from1 as it will be at the risk of temporarily disabling it4 ,in consequence of the time and labor expended in making cells1 in the small way1 testing1 repairing damages done during experiments1 etc41 the cost of the cells now is unavoidably rather high4 ,but if made in a commercial way1 all this would be reduced to a system1 and the cost would be small4 ,i may say here that ,i do not make cells for sale4 ,the applications or uses for these cells are almost innumerable1 embracing every branch of electrical science1 especially telegraphy1 telephony1 and electric lighting1 but ,i refrain from naming them4 ,i may be permitted1 however1 to lay before you two applications1 because they are of such general scientific interest4 ,the first is my ,photometer4--,the light to be measured is caused to shine upon a photo-electric current-generating cell1 and the current thus produced flows through a galvano-metric coil in circuit1 whose index indicates upon its scale the intensity of the light4 ,the scale may be calibrated by means of standard candles1 and the deflections of the index will then give absolute readings showing the candle power of the light being tested4 ,or1 the current produced by that light and that produced by the standard candle may be compared1 according to any of the known ways of arranging and comparing different lights--the cell being lastly exposed alternately to the two lights1 to see if the index gives exactly the same deflection with each light4 ,this arrangement leaves untouched the old difficulty in photometry1 that arising from the different colors of different lights4 ,i propose to obviate that difficulty in the following manner4 ,as is well known1 gold transmits the green rays1 silver the blue rays1 and so on2 therefore1 a cell faced with gold will be acted upon by the green rays1 one faced with silver by the blue rays1 etc4 ,now1 if we construct three cells 7or any other number71 so faced that the three1 collectively1 will be acted upon by all the colors1 and arrange them around the light to be tested1 at equal distances therefrom1 each cell will produce a current corresponding to the colored rays suited to it1 and all together will produce a current corresponding to all the rays emitted by the light1 no matter what the proportions of the different colors may be4 ,the three currents may act upon the same index1 but each should have its own coil1 not only for the sake of being able to join or to isolate their influences upon the index1 but also to avoid the resistances of the other cells4 ,if a solid transparent conductor of electricity could be found which could be thick enough for practical use and yet would transmit all the rays perfectly1 i4e41 transmit white light unchanged1 that would be still better4 ,i have not yet found a satisfactory conductor of that kind1 but ,i think the plan stated will answer the same purpose4 ,this portion of my system ,i have not practically tested1 but it appears to me to give good promise of removing the color stumbling-block1 which has so long defied all efforts to remove it1 and ,i therefore offer it for your consideration4 ,photo-electric regulator4--,my regulator consists of a current-generating cell arranged in front of a light1 say an electric lamp1 whose light represents the varying strength of the current which supports it4 ,the current produced in the cell by this light flows through an electro-magnetic apparatus by means of which mechanical movement is produced1 and this motion is utilized for changing resistances1 actuating a valve1 rotating brushes1 moving switches1 levers1 or other devices4 ,this has been constructed on a small scale1 and operates well1 and ,i think it is destined to be largely used1 as a most sensitive1 simple1 and perfect regulator for currents1 lights1 dynamos1 motors1 etc41 etc41 whether large or small4 ,in conclusion1 ,i would say that the investigation of the physical properties of selenium still offers a rare opportunity for making very important discoveries4 ,but candor compels me to add that whoever undertakes the work will find it neither an easy nor a short one4 ,my own experience would enable me to describe to you scores of curious experiments and still more curious and suggestive results1 but lack of time prevents my giving more than this very incomplete outline of my discoveries4 99 99 99 99 99 ,,electricity ,,applied ,,to ,,the ,,manufacture ,,of ,,varnish4 ,messrs4 ,mthel ,ltche1 of ,berlin1 recommend the following process for the manufacture of varnish3 ,the oils are treated by gases or gaseous mixtures that have previously been submitted to the action of electric discharges4 ,the strongly oxidized oxygenated compounds that are formed under such circumstances give rise1 at a proper elevation of temperature1 to compounds less rich in oxygen1 and the oxygen that is set free acts upon the fatty acid that it is proposed to treat4 ,a mixture of equal parts of chlorine and steam may be very advantageously employed1 as well as anhydrous sulphuric acid and water1 or oxygen1 anhydrous sulphuric acid and protoxide of nitrogen1 nitrogen1 oxygen1 and hydrogen1 protoxide of nitrogen and air1 or oxygen1 and so on4 ,the apparatus is shown in section in the accompanying engraving2 a is a steam-pipe running from the boiler to the motor4 ,from this pipe branch conduits1 b1 that enter the vessels1 ,b1 in which the treatment is effected1 and that run spirally through the oil4 ,at the lower part of the vessel1 ,b1 there is tube wound into a flat spiral1 and containing a large number of exceedingly small apertures4 ,the oxidizing apparatus is shown at p4 ,the gaseous mixture enters through the tube1 n1 traverses the apparatus1 p1 and enters the vessel1 ,b1 through the tubes1 g and ,d4 ,fig4 #b gives the details of the oxidizing apparatus1 which consists of two concentric glass tubes1 ,a and ,f1 soldered at x4 ,a is closed beneath and held in a cylinder1 ,c2 ,f contains a small aperture through which passes a tube1 ,e4 ,the gaseous mixture enters through the latter1 traverses the annular space between the tubes1 ,a and ,f1 and then makes its exit through ,h1 whence it goes to a similar apparatus placed alongside of the other4 ,the shaded parts of the engraving represent bodies that are good conductors of electricity and that communicate with the two poles of any electrice source whatever4 ,illustration3 ,,figs4 #a ,,and #b4 ,the operation is as follows3 ,after opening the tube1 e1 linseed oil is introduced into the vessel1 ,b1 until the latter is half full1 and1 after this1 e is closed and the worm1 ,s1 is allowed to raise the temperature to between #fj and #hj4 ,then the cock of the tube1 d1 which communicates with an air pump1 is opened1 and the pressure is diminished to about #gcj mm4 of mercury4 ,at this moment the oxidizing apparatus are put in communication with an induction bobbin that is interposed in the circuit of a dynamo1 while through the tube1 n1 there is made to enter a mixture of equal parts 7in volume7 of sulphurous acid1 oxygen1 and air4 ,at the same time1 the cock of the tube1 g1 is opened1 while the stirrer1 ,t1 is set in motion4 ,in this way we obtain1 in a much shorter time than by ordinary processes1 a very liquid1 transparent varnish1 which1 when exposed to the air1 quickly hardens4 ,it is possible1 with the same process1 to employ a mixture 7in volumes7 of two parts of protoxide of nitrogen with one and a half parts of atmospheric air1 or even protoxide of nitrogen alone4 ,when it is judged that the operation is finished1 the tube1 g1 is opened1 the stirrer is stopped1 and the tube1 c1 is opened after d has been closed4 ,the steam then forces the varnish to pass through the tube1 f1 and traverse the washing apparatus1 which is filled half full of water1 that is slightly ammoniacal1 and is heated by a circulation of steam1 ,s4 ,finally1 the product1 washed and free from every trace of acid is collected upon making its exit from the tube1 h4--,la ,lumiere ,electrique4 99 99 99 99 99 ,,naglo ,,brothers' ,,telephone ,,system4 ,we borrow from the ,elektrotechnische ,zeitung the following details in regard to the telephonic installations made by the ,brothers ,naglo at ,berlin4 ,fig4 #a gives the general arrangement of a station1 where ,j is an inductor set in motion through a winch1 ,k1 and a pair of friction rollers2 ,w1 a polarized call2 ,u1 an ordinary two-direction commutator2 ,b1 a lightning protector2 and ,l and ,t1 the two terminals of the apparatus1 one of them connecting with the line and the other with the earth4 ,the interesting point of this system is the automatic communication which occurs when the inductor1 ,j1 is moved4 ,at the same moment that the winch1 ,k1 is being moved1 the disk1 ,p1 is carried from right to left and brought into contact with the spring1 f#b4 ,as soon as the winch is left to itself a counter-spring forces the disk1 ,p1 to return to a contact with the spring1 f#a4 ,figs4 #b and #c show the details of such communication4 ,the winch1 ,k1 is keyed to one of the extremities of a sleeve that carries the disk1 ,p1 at its other extremity4 ,this sleeve is fixed upon the axle of the first friction roller1 that is to say1 upon the axle that controls the motion of the inductor1 and is provided at the center with two helicoidal grooves1 e1 at right angles with one another4 ,in these grooves slides a tappet1 n1 connected with the axle4 ,illustration3 ,,fig4 #a4 ,under the influence of the counter-spring at the left of the disk1 ,p1 the latter constantly tends to occupy the position shown in ,fig4 #b1 which is that of rest4 ,as soon as the winch1 ,k1 is revolved1 whatever be the direction of the motion1 the axle can only be carried along when the tappet1 n1 has come to occupy the position shown in ,fig4 #c1 that is to say1 when the disk has moved from right to left a distance corresponding to the fraction of the helix formed in the sleeve4 ,this stated1 it is easy to understand the travel of the currents4 ,fig4 #a shows the station at rest4 ,the current that arrives through ,l passes through the lightning protector1 the body of the commutator1 ,u1 the terminal1 v1 and the call1 ,w1 bifurcates at ,p1 and is closed by the earth4 ,the inductor is in circuit1 but1 as it is in derivation1 upon a very feeble resistance1 v1 nearly the whole of the current passes through the latter4 ,when it is the station that is calling1 the call1 ,w1 is put in derivation upon the circuit1 f#b p1 h1 so that the portion of the circuit that passes through q ,w v is exceedingly feeble1 and incapable of operating the bell of the post that is calling4 ,illustration3 ,,figs4 #b ,,and #c4 ,finally1 when the telephone is unhooked1 the inductor1 ,j1 and the bell1 ,w1 are thrown out of circuit1 and the telephone is interposed between d and i1 that is1 between ,l and ,t4--,la ,lumiere ,electrique4 99 99 99 99 99 ,,the ,,gerard ,,electric ,,lamp4 ,in the ,gerard incandescent lamp the carbons have the form of a ,v4 ,they are obtained by agglomerating very finely powdered carbon1 and passing it through a draw plate4 ,at their extremity they are cemented together with a small quantity of carbon paste1 and their connection with the platinum conducting wires is effected by means of a cylinder of the same paste surmounted by a cone4 ,these couplings secure a good contact1 and1 by their dimensions1 prevent the attachments from becoming hot and consequently injuring the carbon at this point4 ,the cone forms a connection of decreasing section1 and prevents the carbon from getting broken during carriage4 ,this process of manufacture permits of obtaining lamps of all intensities1 from #c candles up4 ,the following1 according to ,mr4 ,gerard1 are the consumptions of energy in each size of lamp3 ,candles4 ,volts4 ,amperes4 ,no4 #j4 #aj #af #a4e #a4 #be #be #b #b4 #ej #cj #b4e ,illustration3 ,,gerard',s ,,incandescent ,,lamp4 ,it will be seen that these lamps require a relatively intense current with much less fall of potential than the ,swan1 for example--this being due to the diameter of the filament4 ,but1 what is an inconvenience as regards mounting1 if we wish to supply them by ordinary machines 7for they must be mounted in series of #c on each derived circuit if the machine gives1 as most frequently the case1 #ajj volts71 is an advantage as regards the quality and steadiness of the light and the duration of the lamps4 ,the part in which the energy is expended is homogeneous1 as might be supposed from the mode of manufacture1 and as may be ascertained from a microscopical examination1 and it is exempt from those variations in composition that are found in carbons of a vegetable nature1 like the ,edison4 ,besides1 being of relatively large diameter1 the lamp is capable of supporting a very great increase of temperature4 ,the process employed for fixing the lamps is as simple as can be4 ,each platinum wire is soldered to a piece of copper that surrounds the base of the lamp and that is fixed to the glass with a special cement4 ,these two armatures intertwine1 but at a sufficient distance apart to prevent contact4 ,they carry a longitudinal projection and an inflation that fit by hard friction into two copper springs connected electrically with the circuit4 ,it is only necessary to lift the lamp in order to remove it from the support2 and the contrary operation is just as easy4--,le ,genie ,civil4 99 99 99 99 99 ,a ,,new ,,reflecting ,,galvanometer4 ,fig4 #a shows an elevation of the instrument and a horizontal section of the bobbins4 ,two pairs of bobbins1 cc1 cc1 are so arranged that the axes of each pair are parallel and in the same vertical plane4 ,each pair is supported by a vertical brass plate1 and the two plates make an angle of about #ajf with each other1 so that the planes containing the axes of the bobbins make an angle of about #gd4 ,two horseshoe magnets1 m m1 made of #a_/be inch steel wire1 are connected by a very light piece of aluminum and placed at such a distance from each other that1 on being suspended1 the two branches of each of the magnets shall freely enter the respective bores of the two bobbins fixed upon the same plate1 and1 when the whole system is in equilibrium and the bobbins free from current1 the two branches of each of the magnets shall nearly coincide with the axes of such bores4 ,the magnets are not plane1 but are curved so as to form portions of a vertical cylinder whose axis coincides with the direction of the suspension wire1 and to which the axes of the bobbins are tangent at their center1 approximately to the points where the poles of the magnets are situated4 ,illustration3 ,,fig4 #a4 ,,gray',s ,,galvanometer4 ,the needles have been given this form so that their extremities shall not touch the sides of the bore during considerable deflections4 ,in the instrument which the inventors1 ,messrs4 ,t4 ,a4 ,gray1 used in their experiments upon the resistance of glass1 the needles were arranged so that their poles of contrary name were opposite4 ,illustration3 ,,fig4 #b4 ,the system of needles is suspended from the extremity of a screw1 p1 which passes into a nut1 n1 movable between two stationary pieces4 ,on revolving the nut1 we cause the screw to rise or lower1 along with the entire suspended part1 without twisting the thread4 ,the four bobbins are grouped for tension1 and have a total resistance of #cj1bbj ohms4 ,they contain #af1jjj feet of ,no4 #ej copper wire1 forming #fb1ici revolutions1 nearly equally divided between the four bobbins4 ,when a current is passing through the bobbins1 the poles of one of the horseshoe magnets are attracted toward the interior of the corresponding bobbins1 while those of the other are repelled toward the exterior by the two other bobbins4 ,we thus have a couple which tends to cause the system to revolve around the suspension axis4 ,a mirror1 which is fixed upon a vertical piece of aluminum1 a1 gives1 in the usual manner1 a reflected image upon a scale1 thus allowing the deflections to be read4 ,a compensating magnet1 ,m1 is supported by a vertical column fixed to the case1 above the needles4 ,this magnet may be placed in the different azimuths by means of a tangential screw1 t4 ,the extremities of the bobbin wires are connected with three terminals1 ,t1 ,t1 ,t1 and the instrument may1 by a proper arrangement1 became differential4 ,these terminals1 as well as the communicating wires1 are insulated with ebonite4 ,thus arranged1 the instrument is capable of making a deflection of one division of #a_/ej inch upon a scale placed at a distance of a little more than a yard1 with the current produced by one daniell of #aj ohms4 ,this is a degree of sensitiveness that cannot be obtained with any of the astatic instruments known up to the present4 ,by regulating the needles properly1 a greater degree of sensitiveness may be attained1 but then the duration of the needles' oscillation becomes too great4 ,the sensitiveness of the instrument is sufficiently great to allow it to be used in many cases1 even with a moderate duration of oscillation4 ,in their experiments upon the resistance of glass1 the inventors employed an instrument that was not arranged for giving great sensitiveness1 and one with which resistances of from #ajd to #aje megohms could be measured by the use of a pile of #abj daniells4 ,the instrument can be given another form4 ,the four bobbins may be arranged symmetrically in the same plane1 and the two horseshoe magnets be supported by an ,s-shaped aluminum bar4 ,the latter traverses the plate that supports the bobbins1 in such a way that one of the magnets enters one of the bobbins that correspond to it on one side of the plate1 and the other on the other side1 as shown in ,fig4 #b4 ,the bobbins are so connected that1 when they are traversed by a current1 both magnets are at the same time attracted toward the interior or repelled toward the exterior of the bobbins4 ,such a form of the instrument has the advantage of being more easily constructed1 while the regulation of the magnets with respect to the bore of the bobbins is easier4 ,the chief advantage of the instrument results from the fact that1 owing to the arrangement of the magnets and bobbins1 a large portion of the wires of the latter is situated very near the poles of the magnets1 and in a position very favorable for electro-magnetic action4 ,the instrument presents no difficulties as regards construction1 and costs no more than an ordinary one4 ,we might even arrange a single horseshoe magnet1 or an ,s-shaped one1 horizontally1 and employ but a single pair of bobbins1 and thus have a non-astatic apparatus based upon the same principle4 ,but in astatic instruments it is better to place the magnets in such a way that the two branches shall be in the same vertical plane4 ,were the line that joins the two poles vertical1 the system would be perfectly astatic in a uniform field1 since each magnet in particular would then be perfectly astatic4 ,a pair of horseshoe magnets may thus be regulated in such a way as to form a perfectly astatic system in a uniform field and to preserve an almost invariable zero1 this being something that it is very difficult to obtain with the ordinary arrangement of needles1 especially when a compensating magnet is used2 for1 in such a case1 one of the needles becomes more or less magnetized1 while the other becomes demagnetized1 according to the position of the compensating magnet4--,la ,lumiere ,electrique4 99 99 99 99 99 ,,histological ,,methods4 ,a cat1 dog1 rabbit1 or ,guinea pig will furnish parts from which sections can be cut for the study of histology4 ,whichever animal is selected should be young and well developed4 ,put it under influence of chloroform1 and open into the cavity of the chest2 make an incision into the right ventricle1 and allow the animal to bleed to death2 cut the trachea and inject the lungs with a solution of one and a half drachms of chromic acid in one quart of water1 care being taken not to overdistend the lung4 ,tie the severed end to prevent the escape of the fluid1 and carefully remove the lung4 ,it is a difficult thing to do this without rupturing it1 but with care and patience it can be done4 ,place the lungs in a solution of the same strength as used for injecting2 after fifteen or twenty hours change it to a fresh solution1 and allow it to remain for about a month1 and then change it to rectified spirits1 in which it may remain until required4 ,cut the tongue into several transverse and longitudinal pieces1 also the small intestines1 and put them into a solution of fifteen and one-half grains chromic acid1 thirty grammes bichromate of potash1 and three pints of water2 change the solution the next day1 and let them remain two weeks and then place in spirits4 ,cut longitudinal and transverse portions of the stomach and large intestines1 wash in a weak solution of salt and water1 and put them in the same solution as used for the lungs1 and treat similarly4 ,cut the kidneys longitudinally and transversely1 and put them in a solution of six and one-half drachms bichromate of potash1 two and one-half drachms sodium sulphate1 one quart of water2 change the solution the next day1 and at the end of four weeks transfer to alcohol4 ,wash the inner surface of the bladder with salt and water1 and after cutting it longitudinally and transversely1 put the sections in a solution of three drachms bichromate of potash in a quart of water4 ,cut the liver into small parts1 and place in the same solution as used for the kidneys2 change the solution after a day1 and let them remain four or five weeks1 then change to spirits4 ,the spleen and portions of the thin abdominal muscles may be placed in a solution of three drachms chromic acid to one quart of water1 and transferred to alcohol after three or four weeks4 ,carefully remove an eye and divide it behind the crystalline lens1 put the posterior portion in a solution made by dissolving fifteen grs4 chromic acid in five drachms water1 and slowly adding five and one-half ounces alcohol2 change to spirits in two weeks4 ,the lens should be put in the same solution1 but should remain a few days longer4 ,open the head1 remove the brain1 and place transverse and longitudinal sections of it in spirits for eighteen hours1 then transfer to a solution of one drachm chromic acid in a quart of water1 and let it remain until hard enough to cut4 ,place the uterus in a solution of one and one-half drachms chromic acid in one quart of water1 change to a new solution the next day1 and at the end of a month transfer to alcohol4 ,the bones from one of the legs should be carefully cleaned of its muscles1 cut into several pieces1 and placed in a solution of fifteen and one-half grains chromic acid1 one-half drachm nitric acid1 and six ounces water4 ,change the fluid frequently until the bones are sufficiently softened1 and then change to alcohol4 ,section cutting machines for cutting sections can be procured of the dealers1 but a very simple and effective one can be easily made if one does not wish to go to the expense of buying an instrument4 ,a strip of wood twelve or fourteen inches long and about two inches wide has attached to its center a bridge-shaped piece of wood1 a1 ,fig4 #a4 ,this is covered with a brass plate1 c1 pierced with a hole one-half of an inch in diameter4 ,this hole extends through the wood1 and is fitted with a piston4 ,two long narrow inclined planes of nearly equal inclination1 b1 b1 grooved to slide on each other1 are placed under the bridge2 the lower is to be fastened to the board2 the end of the piston rests on the upper one4 ,the object from which we desire to cut a section is placed in the hole1 in the piston4 ,if the upper plane be pushed in1 the piston will be forced upward1 and with it the object4 ,as the inclination of the plane is very gradual1 the vertical motion will be very slight as compared with the horizontal4 ,when the object is raised a little above the brass plate1 a keen edged razor1 thoroughly wet1 is pushed over the hole1 cutting the object4 ,this gives the section a smooth surface1 and even with the plate2 now push the plane forward one-eighth to one-quarter of an inch1 and cut again2 this will give a thin section of the object4 ,the thickness of the section depends1 of course1 on the distance the wedge is pushed4 ,with a little practice1 much better sections can be cut by the hand than by any machine2 this does not apply of course to large sections4 ,a razor of good steel1 with a blade thin and hard1 are the most essential points in an instrument for hand cutting4 ,for ordinary purposes it is not necessary to have the blade ground flat on one side1 although many prefer it4 ,the knife should always be thoroughly wet1 in order that the cut tissue may float over its surface4 ,water1 alcohol or salt and water may be used for this purpose4 ,illustration3 ,,fig4 #a4 ,to out a section by hand1 hold the object between the thumb and first two fingers of the left hand1 supporting the back of the knife by the forefinger4 ,the knife is to be held firmly in the right hand1 and in cutting should never be pushed1 but drawn from heel to point obliquely through the tissue4 ,the section should be removed from the knife by a camel's hair brush4 ,when the object is too small to hold1 it is usually embedded in some convenient substance4 ,a carrot is sometimes very useful for this purpose4 ,a hole rather smaller than the object is cut out of the middle4 ,put whatever is to be cut into this1 and cut a thin section of the whole4 ,the carrot does not cling to either the knife or the section1 and the knife is wetted at every slice by it4 ,paraffin is the agent usually employed for embedding purposes4 ,melt it1 and add a little lard to soften it2 the addition of a little clove oil renders it less adhesive4 ,melt the paraffin at as low a temperature as possible1 and pour it into a paper cone4 ,dip the object into this and remove immediately2 as soon as the layer of paraffin surrounding it becomes hardened1 replace it in the paraffin2 this prevents overheating the tissues4 ,where the tissues are too soft to be cut1 they may be soaked in a solution of gum arabic and dried2 in this condition they can be readily cut1 after which the gum can be dissolved off4 ,this is an extremely useful method for cutting the lung or other organs where an interstitial support is needed4 ,for a very thin object1 a cork fitting any kind of a tube is to be split1 and the object placed between the two parts2 the cork is then thrust into the tube1 and a sufficient degree of firmness will be obtained to allow cutting4 ,the sections should always be manipulated with camel's hair brushes4 ,much practice will be required before dexterity is attained4 ,methods of preserving the tissues4--,all water must be removed from the tissue1 either by drying or by immersing it in rectified spirits1 and then in absolute alcohol1 and the alcohol driven off by floating it upon oil of clove or turpentine4 ,the substances used to preserve the tissues are ,canada balsam1 ,dammar balsam1 glycerine1 ,farrant's solution1 potassium acetate1 spirits1 naphtha1 and creosote4 ,the section is to be floated on to the slide or placed in position with a camel's hair brush4 ,it should be spread out1 and then examined under the microscope for the purpose of improving its position if necessary1 or of removing any foreign particles4 ,a drop of the preserving medium is then placed upon it1 and another placed on the cover and allowed to spread out4 ,the cover is then taken by a pair of pincers and inverted over the object1 and one edge brought to touch the slide at one part of its margin4 ,the cover is then gently lowered1 and the whole space beneath the cover filled and the tissue completely saturated4 ,if air bubbles show themselves1 raise the cover at one corner and deposit a further quantity of the medium4 ,the slide should be set aside for a few days4 ,first1 the excess of the medium must be removed2 if it is glycerine1 much of it can be removed by a piece of blotting paper1 but the cover must not be touched1 for it is easily displaced2 that near the cover can be replaced by a camel's hair brush4 ,a narrow ring of glycerine jelly should be placed around the edge of the cover1 to fix it before the cement is applied4 ,when this has set1 a narrow strip of cement is to be put on1 just slightly overlapping the edge of the cover and outside the margin of the jelly4 ,until it has been perfectly secured1 a slide carrying glycerine must never be placed in an inclined position1 as its cover will slide off4 ,preservative media4--,canada balsam may be prepared as follows3 ,place some pure ,canada balsam in a saucer1 and cover with paper to exclude dust2 dry it in an oven at a temperature of #aej2 when it cools1 it will become hard and crystalline4 ,dissolve this in benzole1 and use in the same way as glycerine4 ,dammar is now used as a substitute for ,canada balsam4 ,by its use the tissues are rendered more transparent4 ,to prepare it1 dissolve one-half ounce of ,dammar rosin and one-half ounce of gum mastic in three ounces of benzole1 and filter4 ,this may be used to mount unsoftened bone and tooth1 hair1 brain1 and spinal column1 and most tissues that have been hardened in alcohol or chromic acid1 which require to have their transparency increased4 ,glycerine is not adapted for white fibrous tissue or blood vessels1 unless they have been hardened in chromic acid1 as it causes the white fibers to swell up and lose their normal features4 ,sections of liver1 lung1 skin1 and alimentary canal show better in glycerine unless they have been stained4 ,farrant's solution may be substituted for glycerine in many instances1 because of its feebler tendency to render the tissues transparent4 ,it consists of equal parts of gum arabic1 glycerine1 and a saturated solution of arsenious acid4 ,in mounting preparations with this medium1 the covered object should be allowed to lie a day before the varnish is applied1 so that the cover may be fixed1 and thereby prevented from being displaced4 ,rectified spirits may be used for mounting softened bone and tooth1 and naphtha and creosote are useful for preserving urinary casts4 ,when the section is mounted in ,canada or ,dammar balsam1 no cement is required1 but for all other preservative media the margin of the cover must be covered with cement4 ,to do this1 dry the edges of the cover thoroughly with bibulous paper1 and paint a layer of gold size1 allowing it to overlap the cover an eighth or sixteenth of an inch1 then cover this with white zinc cement4 ,preparation for mounting the different tissues4--,to obtain a section of bone or tooth requires a grinding down of the tissue until it is so thin as to be transparent4 ,a section should first be cut as thin as possible by a fine saw4 ,it should be attached by the flattest side to a piece of glass1 and then ground down by a grindstone or by very fine emery1 on a perfectly flat piece of lead4 ,when sufficiently thin and transparent1 mount in rectified spirits or ,dammar4 ,sections of the tongue may be made by embedding in paraffin1 and mounted in ,farrant's solution or glycerine4 ,sections of the stomach may also be made by embedding in paraffin1 but better ones can be made by freezing4 ,farrant's solution makes a good mounting4 ,the intestines also give a better section from freezing than by embedding1 as the paraffin injures the villi2 mount in the same medium as the stomach4 ,the liver may be embedded in paraffin1 and the section mounted in ,farrant's solution or glycerine4 ,the kidney may be treated in the same way4 ,the cornea of the eye can be readily cut by embedding in paraffin1 and the section may be mounted in ,farrant's solution4 ,the crystalline lens and retina may be treated similarly4 ,the brain and spinal cord should be embedded in paraffin or a carrot1 and the section mounted in ,dammar4 ,sections of the uterus and ovaries are best mounted in glycerine or ,dammar4 ,sections of lung maybe made by embedding in gum or by freezing1 and mounted in ,farrant's solution4 ,every slide should be of uniform size1 and labeled4 ,the usual size is #ca inches1 and should be of a good quality of glass1 free from scratches or air holes4 ,they may be labeled either by writing with a diamond1 or a small piece of paper affixed to one end1 on which is written what is required4 99 99 99 99 99 ,,life ,,history ,,of ,a ,,new ,,septic ,,organism4 ,at a recent meeting in ,london1 of the ,royal ,miscroscopical ,society1 ,dr4 ,dallinger gave his annual address to what was probably the largest gathering of ,fellows ever assembled on a similar occasion4 ,after briefly referring to the increased interest lately manifested in the study of minute organisms1 and recalling the characteristics of the doctrines of abiogenesis and biogenesis1 he passed rapidly in review the results of the observations of ,tyndall1 ,huxley1 and ,pasteur as bearing upon these questions1 and called attention to the observations of ,buchner as to the transformation of ,bacillus anthracis and ,bacillus subtilis1 and vice versa1 and referred with approval to ,dr4 ,klein's criticisms thereon4 ,having spoken of the desirability of careful and continuous study of this class of organisms1 and the importance of endeavoring to establish the relation of the pathogenic form to the whole group1 he said he should be better able to deal with the subject by recording a few ascertained facts rather than by making a more extended review1 and he therefore devoted the main part of his address to a description of the life history of a septic organism hitherto unknown to science4 ,in his observations of this form--extending over four years--he had the advantage of the highest quality of homogeneous lenses obtainable1 ranging from one-tenth to one-fiftieth of an inch1 his chief reliance being placed upon a very perfect one thirty-fifth of an inch2 and from the continuous nature of the observations as well as the circumstances under which they were carried on1 dry lenses had for the most part to be employed4 ,having in his possession a maceration of cod-fish in a fluid obtained from boiled rabbits1 he found at the bottom of it1 when in an almost exhausted condition1 a precipitate forming a slightly viscid mass1 to which his attention was particularly directed4 ,it was seen to contain a vast number of ,bacterium termo1 but on examination with a one-tenth inch objective showed that it also contained a comparatively small number of intensely active organisms--one being discovered in about eight or ten drops of the sediment4 ,these measured #a-aj1jjj of an inch in length by #a-ai1ejj of an inch in breadth4 ,the fluid had originally been kept at a temperature of #ij to #ie ,f41 and it was noticed that1 when placed upon a cold stage under the microscope1 the movements of the organisms became1 gradually slower1 until at last they entirely ceased2 the necessity1 therefore1 arose for the use of a warm stage1 and the very ingenious contrivance by which a continuous and even temperature was maintained within the one-tenth of a degree was exhibited4 ,the greatest difficulty in the matter was1 however1 experienced in obtaining specimens for observation1 in order to be able to trace them from their earliest to their latest stage4 ,the ,president then explained1 by means of an admirable series of illustrations projected upon a screen by the oxyhydrogen lantern1 the life history of the organism to which he had referred1 exhibiting it first as a translucent1 elliptic1 spindle-shaped body1 with six long and delicate flagella1 the various positions in which the five specimens were drawn giving a very good idea of its peculiar porpoiselike movements4 ,the various positions which it assumed in making an attack upon a portion of decomposed matter were also shown1 the movements quite fascinating the observer by their rhythmical character4 ,the supposed action of the flagella in the production of the movements observed was explained1 distinct evidence being afforded of a remarkable spiral motion1 at least of those behind4 ,the process of fission was illustrated in all its observed stages from the first appearance of a construction to that of final and complete separation1 the whole being performed within the space of eight or nine minutes4 ,a description of the process of fusion from the simple contact of two organisms to their entire absorption into each other followed1 as well as their transformation into a granular mass1 which gradually decreased in size in consequence of the dropping of a train of granules in it wake as it moved across the field4 ,the development of these granules was traced from their minute semi-opaque and spherical form to that of the perfect flagellate organism first shown1 the entire process being completed in about an hour4 ,experiments as to their thermal death-point showed that1 while the adults could not be killed by a temperature less than #adf ,f41 the highest point endured by the germs was #aij ,f4 ,illustrations of a variety of other modes of fission discovered in previous researches on similar forms were given1 showing the mode of multiple division and a similar process in the case of an organism contained in an investing envelope4 ,the ,president concluded his address1 which was listened to throughout with the greatest attention1 by remarking that1 though the processes could be seen and their progress traced1 the modus operandi was not traceable4 ,yet the observer could not fail to be impressed with the perfect concurrent adaptation of these organisms to the circumstances of their being2 they were subject to no caprices1 their life-cycles were as perfect as those of a crustacean or a bird1 and while the action of the various processes was certain1 their rapidity of increase and the shortness of their life history were such that they afforded a splendid opportunity of testing the correctness of the ,darwinian law4 99 99 99 99 99 ,,winter ,,and ,,the ,,insects4 ,for a number of years previous to #ahgh we had in ,pembroke but little or no severe cold1 owing to the prevalence of southeast1 south1 west1 and especially southwest winds4 ,in many places1 fuchsias that were left in the ground for the entire year had not been frozen to the root within the memory of man4 ,some of these plants had grown to be trees five or six yards in height1 and with a trunk the size of one's leg4 ,now1 during the same series of years1 many insects that are common throughout the rest of ,great ,britain did not cease to be rare with us1 or rather were confined to certain circumscribed limits4 ,thus1 the ,noctuellae1 with the exception of a few species abundant everywhere1 were almost wanting1 and ,i know of no other country where the dearth of common species of nocturnal butterflies was so great4 ,but during the winter of #ahgh there supervened a radical change4 ,persistent winds from the northwest1 driving back the currents of warm air from the south1 brought on an intense cold that froze everything2 or1 when some variation occurred in them1 clouds formed and dissolved into a rain that immediately froze1 so that the large roads remained for weeks covered with a layer of rime from two to four inches thick4 ,illustration3 ,,green ,,woodpecker ,,searching ,,for ,,insects4 ,the winters of #ahgi and #ahhj were equally cold2 we may even say that the latter was the severest that had been experienced in fifty years4 ,this year the sea-sand1 along with the ice and snow1 formed a thick crust all along the tide-line--this being something rarely seen along our coast4 ,the first of these three winters 7#ahgh-ahgi7 killed all the arborescent veronicas and a few sumacs4 ,as for the fuchsias and myrtles1 they were frozen down to the level of the soil4 ,i now come to the effects of this severe cold upon the insects4 ,the ,lepidoptera1 which before were rare1 became more and more common in #ahgi1 #ahhj1 and #ahha1 and so much so that during the last named year they abounded2 and species that had formerly been detected only at certain favored points spread over the entire coast and into the interior of the country4 ,the geometers appeared in numbers that were unheard of4 ,but this change was especially striking as regards the ,noctuellae1 in view of the previous rarity of the individuals belonging to this family4 ,we have here an example of the direct relation of cause to effect1 although ,i am not in a position to assert that the effect is always produced in the same way4 ,to me there is no question as to the fact that the constitution of those insects which nature has accorded the faculty of liberating is strengthened1 and that their chances of life are increased1 if the cold of winter is intense enough to plunge them into an absolute rest1 and is not unseasonably affected by warm1 spring-like days4 ,it is certain that such cold is capable of contributing largely to the multiplication of the individuals of such species as hibernate in the egg state1 and it also has a beneficent influence upon those species which1 like the small social larvae1 pass this season upon the earth enveloped in a silken envelope1 or1 like the larvae of the ,noctuellae1 between dead leaves or upon the ground itself4 ,on another hand1 it cannot be doubted that mild winters greatly contribute to the bringing about of a destruction of larvae and chrysalids in two ways3 ,first1 they favor the development of mould1 which1 as well known1 attacks the larvae of insects when these have been enfeebled by an excess of rain or dampness2 and second1 they permit beasts of prey to continue to exercise their activity4 ,now1 these latter are numerous4 ,moles1 instead of burying themselves deeply1 then continue to excavate near the surface1 and shrew mice are constantly in search of food4 ,these small mammals1 which abound in this district1 destroy a large number of chrysalids of ,lepidoptera4 ,it is the same with birds4 ,as soon as severe cold begins to prevail in the north and east1 they come in troops to the open fields and the sheltered slope of the hills of our district4 ,but it is scarcely worth while to stop to tell of the skill and perseverance of these destroyer of larvae4 ,we may mention1 the woodpecker1 however1 as a skillful searcher for insects that lie hidden in places where the sun has melted the snow4 ,the carnivorous ,coleoptera and the ,forficulae are likewise generally in motion during mild winters4 ,doubtless these last-named do not make very large inroads in the ranks of larvae and chrysalids every day2 yet1 having no other food1 they destroy a goodly number of them4 ,but ,i believe that the devastations made in the army of insects by all these enemies united do not equal those made by certain crustaceans--the wood lice4 ,during mild winters these pests multiply1 eat1 and prosper out of bounds1 and to such a point that1 in a climate like ours1 they become a true scourge that prevails everywhere1 out of doors and within4 ,once in a place1 they begin to look for larvae and chrysalids1 which they devour4 ,the severe cold seems to have destroyed a certain number of them1 since they are now not so numerous by far2 and it has at least certainly put a stop to their devastations at an epoch when the larvae are more particularly exposed to the attacks of their enemies4 ,it is to this cause1 as well as to the preceding1 that ,i am led to attribute the extraordinary multiplication of so many species during the three last summers1 which were separated by severe winters4 ,last winter was mild1 and there is therefore no reason to expect that there will be another multiplication2 but ,i hope that the harm done by such a season will be slight4 ,it is the progressive multiplication of the destroyers1 joined to the correlative disappearance of the victims caused by a series of temperate seasons1 that is to be feared4 ,in support of the proposition that ,i maintain1 ,i may mention still another fact4 ,while this district 7,pembroke1 ,wales7 is relatively poor in species whose larvae feed and hibernate in the open air a few species of ,noctuellae1 whose larvae live buried in the earth1 are always abundant4 ,the country is relatively rich in spices of ,tortrix1 which develop and hibernate in the stalks or roots of plants4 ,it is also worthy of remark that very few of our species seem to be incapable of enduring a severe winter4--,c4,g4 ,barret1 in ,science et ,nature4 99 99 99 99 99 ,,silk ,,worm ,,eggs4 ,prof4 ,c4,v4 ,riley1 entomologist1 announces that the ,department of ,agriculture1 ,washington1 will purchase during the coming summer such quantities of silk worm eggs as may be deemed necessary for the distribution that it is proposed to make for the season of #ahhf4 ,so far as found practicable1 the eggs will be purchased of ,american producers4 ,there are certain precautions1 however1 that must be taken to insure purchase4 ,eggs of improved races only 7preferably of the ,french or ,italian ,yellow ,races7 will be bought1 and the producer should send one or two samples of pierced cocoons with the eggs4 ,in addition to this the producer must conform to certain rules to be hereafter explained1 so that an examination may be made that will serve to show the degree of purity of the eggs4 ,no silk culturist should use his crop for the production of eggs unless the worms have shown1 until they began the spinning of their cocoons1 every sign of perfect1 robust health4 ,any indication of the disease called flacherie1 from which the worms so often die after the fourth moult and turn black from putrefaction1 or of any other disease from which silk worms suffer1 should be considered as ample reason for not using the cocoons for the purpose in question4 ,they should1 on the other hand1 be sold for the filature4 ,if the worms have all the indications of health until the spinning period1 then the cocoons may be used for the production of eggs4 ,the following brief instructions will prove of service to those who which to secure sound eggs3 ,illustration ,for each ounce of eggs to be produced1 about three-quarters of a pound of fresh cocoons from the finest and firmest in the lot should be chosen4 ,these should be strung in sets upon a thread1 care being taken not to pierce the chrysalis1 and the strings hung in a cool1 darkened room4 ,the moths generally emerge from the cocoons early in the morning1 and will be seen crawling about over these1 the males being noticeable by their smaller abdomens1 more robust antennae1 and by their greater activity4 ,the moths should be placed1 regardless of sex1 on a table1 where they will soon find their mates and couple4 ,as soon as formed1 the couples should be removed to another table1 that they may not be disturbed by the flutterings of the single moths4 ,there should be prepared for each ounce of eggs to be produced1 about one hundred small bags of fine muslin1 made in the following manner3 ,cut the cloth in pieces #cf inches4 ,then fold one end over so as to leave a single edge of about three-quarters of an inch1 as shown in the accompanying cut4 ,this should be sewn up into a bag with the upper end open1 and then turned inside out1 so that the seams will cause the sides to bulge4 ,thus completed they are called cells4 ,the cells should be strung on a cord stretched across the room4 ,the moths couple as a rule about eight o'clock in the morning4 ,about four in the afternoon they should be separated by taking them by the wings and drawing them gently apart4 ,each female should now be placed by herself in a cell1 which is then closed by a pin as shown in the figure4 ,here she will lay her eggs and in due time die4 ,the males may as a rule be thrown away1 but it is wise to keep a few of the more active ones1 in case there should be a superabundance of females the following day4 ,when the females have finished laying their eggs1 which operation occupies about thirty-six hours1 they are ready to be shipped to this office4 ,the cells1 with their inclosed moths and eggs1 should be placed in a strong box of wood or tin1 being packed in such a manner that they will not be crushed1 and mailed to the entomologist at the department4 ,by using the inclosed return penalty slip1 payment of postage may be avoided4 ,the name of the sender should be placed in each box4 ,the moths1 as soon as received1 will be examined microscopically1 and the eggs of those which are found to be free from disease will be weighed and paid for at the rate of #b4ej per ounce of #be grammes 7about #f-g of an ounce avoirdupois74 ,silk culturists are advised not to attempt the production of eggs unless they are adepts at the industry1 and have had at least one season's experience4 ,we would advise each person desiring to sell1 to send a sample first1 with a statement of the quantity offered4 99 99 99 99 99 ,dr4 ,zintgraff of ,bonn has taken a phonograph with him to ,africa4 ,he intends to bring home phonograms of the savage dialects which he will hire the natives to speak into the machine4 99 99 99 99 99 ,,nature4 ,,determining ,,the ,,mean ,,density ,,of ,,the ,,earth4 ,in ,nature for ,march #e 7p4 #djh7 ,prof4 ,mayer suggests an improvement in our method of determining the mean density of the earth1 from which it appears that our plan has not been properly understood4 ,this misunderstanding1 no doubt1 has arisen from the incomplete description of our method given in the ,nature 7,jan4 #ae4 p4 #bfj7 report of the ,proceedings of the ,berlin ,physical ,society1 which report was probably the only source of information accessible to ,prof4 ,mayer4 ,we are led therefore to give a short description of our method4 ,let ,h ,i ,k ,l represent a section of a cubical block of lead1 about two meters in the edge1 and weighing #ajj1jjj kilos4 ,the balance1 ,a ,b ,c1 is placed in the middle of the upper horizontal surface4 ,it bears the scale-pans1 ,d and ,e4 ,under these scale-pans the block is bored vertically through1 and two other scale-pans1 ,f and ,g1 are suspended below the block1 attached to the balance by means of rods passing through these openings4 ,a weight ,d is brought into equilibrium by weights in ,g4 ,the weight in ,d is acted upon by the earth's attraction that of the block1 and that in ,g by the earth's attraction - that of the block4 ,the weights in ,g are then greater than that in ,d by twice the attraction of the block4 ,the weight in ,d in now removed to ,f1 and counterbalanced by weights in ,e4 ,the weight in ,e will be less than that in ,f by twice the attraction of the block4 ,the difference of the two weighings gives therefore four times the attraction of the block4 ,a correction must be introduced for the variation in the earth's attraction due to the different heights of ,d1 ,e and ,f1 ,g4 ,illustration ,in order to obtain as great a deflection of the balance by the method suggested by ,prof4 ,mayer1 each of the mercury spheres must exert the same attraction as our lead block4 ,this would require spheres having radii of about one meter4 ,the length of the beam of the balance would be necessarily at least two meters4 ,besides1 each mass of mercury1 would exert some attraction on the weight on the other side1 and thus lessen the deviation of the balance4 ,the method given by ,prof4 ,mayer1 except for the suggested employment of mercury1 is then no improvement on ours4 ,if we should use mercury1 we would construct a cubical vessel to contain it1 and use it as we propose to use the lead block4 ,the advantage of using mercury is1 however1 counterbalanced by the difficulty of obtaining it in such large quantities as would be necessary4 ,,arthur ,,konig4 ,,franz ,,richarz4 ,berlin1 ,physical ,institute of the ,university1 ,march #ae4 99 99 99 99 99 ,,physics ,,without ,,apparatus4 ,the ,porosity and ,permeability of ,bodies4--,take two tumblers of the same size1 place one of them upon a table1 and pour into it a small quantity of nearly boiling water4 ,cover this glass with a sheet of cardboard1 and invert the other one upon it4 ,this second tumbler must be previously wiped so as to have it perfectly dry and transparent4 ,in a few seconds the steam from the lower tumbler will traverse the cardboard 7which will thus exhibit its permeability71 and will gradually fill the upper tumbler1 and condense and run down its sides4 ,wood and cloth may be experimented with in succession1 and will give the same results2 but there are other substances that are impermeable1 and will not allow themselves to be traversed4 ,such1 for example1 is the vulcanized rubber of which waterproofs are made4 ,this experiment explains to us why fog is1 as has been well said1 so penetrating4 ,it traverses the tissue of our overcoat and of our flannel1 and comes into contact with our body4 ,on the contrary1 a rubber coat preserves us against its action4 ,illustration3 ,fig4 #a4--;,,experiment ,,upon ,,the ,,permeability ,,of ,,bodies4 ,a ,hot ,air ,balloon4--,make a hollow cylinder of small diameter out of a sheet of paper such as is used for cigarette packages1 and turn in the ends slightly so that it shall preserve its form4 ,if the cylinder seems too difficult to make1 a cone may be substituted4 ,now set fire to the cylinder or cone at its upper part4 ,the paper will burn and become converted into a thin sheet of ashes1 which will contract and curl inward4 ,this light residuum of ashes1 being filled with air rarefied by combustion1 will suddenly rise to a distance of two or three yards4 ,here we have a ,montgolfier balloon4--,la ,nature4 ,illustration3 ,fig4 #b4--,,principle ,,of ,,the ,,hot ,,air ,,balloon4 99 99 99 99 99 ,,the ,,casino ,,at ,,monte ,,carlo4 ,the little city is situated about half way between ,nizza and ,mentone1 and it formerly was the chief city of a principality that belonged to the family ,grimaldi4 ,prince ,florestan sold in #ahfj his royal prerogatives to the ,emperor ,napoleon1 for three million francs1 consequently the land came under the jurisdiction of the ,french republic1 but the city remained in the ,prince's possession1 who1 however1 gave to the gambler ,blanc the privilege of erecting a gambling house upon the rocky shore of the sea4 ,illustration3 ,,the ,,casino ,,at ,,monte ,,carlo4 ,enormous sums of money were spent to give this isolated cliff its present appearance1 covered as it is with beautiful buildings1 hotels1 and villas1 besides the magnificent ,casino building1 which was erected in #ahfb4 ,directly facing the sea1 there is a succession of most beautiful gardens and terraces4 ,but this establishment1 which seems like paradise1 has had a most disastrous effect upon thousands of persons1 and for a long time the subject of influencing the ,french government to put a stop to this gambling house has been agitated4 ,it can scarcely be imagined how much misery it has already caused4 ,it is evident to every one that the keeper of the bank makes considerable profit1 as the chances are #fc times greater in his favor than those of the player4 ,it is admitted that the profits amount every year to #ag million francs4 ,one can well imagine how many fortunes have been consumed every year to make this profit2 but the number cannot be determined4 99 99 99 99 99 ,,on ,,an ,,express ,,engine4 ,it is a somewhat unpromising morning--the river is dark with fog and the huge arch of the station nearly hidden by mist and steam4 ,a cold1 damp wind makes the passengers hurry into the carriages1 and strikes us sharply as we step on to the foot-plate of the engine1 which has just joined the train4 ,but as we get behind the shelter of the screen1 we feel a generous and slightly unctuous sensation of warmth very comforting to a chilly man4 ,the brasswork of the engine shines brilliantly1 the footboard has been newly scrubbed1 and the driver and stoker stand waiting for the signal4 ,the needle shows that the steam is just below the pressure at which it would begin to blow off2 the water in the gauge glass is just where it ought to be2 in fact1 the engine is in perfect condition and ready for a start4 ,the line is clear1 the guard's whistle is answered by our own1 and we glide almost imperceptibly past the last few yards of the platform4 ,the driver opens the regulator till he is answered by a few sounding puffs from the funnel1 and then stands on the lookout for signals so numerous that one wonders how he can tell which of the many waving arms is raised or lowered for his guidance4 ,so he goes on1 with hand on regulator and lever1 gradually admitting more steam as signal after signal comes nearer and then flies past us1 till at last we are clear of the suburbs and find ourselves on a gentle incline and a straight road1 with the open fields on either side4 ,it is now that the real business of the journey begins4 ,locomotives are as sensitive and have as many peculiarities as horses1 and have to be as carefully studied if you would ride them fast and far4 ,the lever is put into the most suitable notch for working the steam expansively2 the driver's hand is on the regulator1 not to be removed for the rest of the trip2 the furnace door is thrown wide open1 and firing begins in earnest4 ,here it may not be amiss to state1 for the benefit of the uninitiated1 that the regulator controls the supply of steam from the boiler1 while the lever enables the driver to reverse the engine1 or1 as we have already stated1 to expand the steam by cutting it off before the end of the stroke4 ,the engine answers to the appeal like a living thing1 and seems1 with its steady beat and sonorous blast1 to settle down to its work4 ,it is pleasant from our seat in the corner of the screen to see this preparation for the work ahead--the absolute calm of driver and stoker1 who exchange no word1 but go steadfastly and quietly about their business2 to feel the vibrations from the rails beneath throb through one with slowly increasing rapidity1 or watch the trees and houses go past as gulls flap past a boat4 ,for there is a certain apparent swagging movement of the objects past which one travels which can only be likened to the peculiar flight of a large sea-bird4 ,but now there are signs of increased activity on the foot-plate2 the stoker is busy controlling the feed of water to the boiler1 and fires at more frequent intervals2 the driver's hand moves oftener as he coaxes and encourages the engine along the road1 his slightest gesture betraying the utmost tension of eye and ear2 the stations1 instead of echoing a long sullen roar as we go through them1 flash past us with a sudden rattle1 and the engine surges down the line1 the train following with hot haste in its wake4 ,we are in a cutting1 and the noise is deafening4 ,looking ahead1 we see an apparently impenetrable wall before us4 ,suddenly the whistle is opened1 and we are in one of the longest tunnels in ,england4 ,the effect produced is the opposite of that with which we are familiar in a railway carriage1 for the change is one from darkness to light rather than from light to darkness4 ,the front of the fire-box1 foot-plate1 and the tender1 which had been rather hazily perceived in the whirl of surrounding objects1 now strike sharply on the eye1 lit up by the blaze from the fire1 while overhead we see a glorious canopy of ruddy-glowing steam4 ,the speed is great1 and the flames in the fire-box boil up and form eddies like water at the doors of an opening lock4 ,far ahead we see a white speck1 which increases in size till the fierce light from the fire pales1 and we are once more in open day4 ,the weather has lifted1 the sky is gray1 but there is no longer any appearance of mist4 ,the hills on the horizon stand out sharply1 and seem to keep pace with us as the miles slip past4 ,the line is clear2 but there is an important junction not far distant1 and we slacken speed1 to insure a prompt pull-up should we find an adverse signal4 ,the junction signals are soon sighted2 neither caution nor danger is indicated1 and1 once clear of the station1 we steam ahead as fast as ever4 ,one peculiarity of the view of the line ahead strikes us4 ,looking at a railroad line from a field or neighboring highway1 even where the rails are laid on a steep incline1 the rise and fall of the road is not very strikingly apparent4 ,seen through the weather-glass1 the track appears to be laid up hill and down dale1 like a path on the downs above high cliffs4 ,over it all we advance1 the engine laboring and puffing on one or two heavy gradients1 in spite of a full supply of steam1 or tearing down the inclines with hardly any1 or none at all and the brake on4 ,and here it may be noted that1 like modern men1 modern engines have been put upon diet1 and are not allowed to indulge in so much victual as their forefathers4 ,the engine-driver1 like the doctor of the new school1 is determined not to ruin his patient by over-indulgence1 and will tell you severely enough that he will never be guilty of choking his engine with an over-supply of steam4 ,in the mean time1 the character of the country we travel through has changed4 ,it has become more open1 and there is a stiff sea-breeze1 which makes itself distinctly felt through the rush of air produced by the speed at which we are going4 ,we fly past idle streams and ponds1 and as the steam swirls over them are disappointed at producing so little effect2 but the ducks1 their inhabitants1 are well used to such visitations1 and hardly deign to move a feather4 ,suddenly we plunge into a series of small chalk cuttings1 and on emerging from them find ourselves parallel with a grand line of downs4 ,we speed by a curve or two1 and find ourselves on the sea-shore2 one more tunnel1 and with steam off we go soberly into the last station4 ,but there is one step more4 ,the breeze blows about our ears4 ,before us the rails are wet1 for the sea swept over them not many hours since1 and to accomplish the last few yards of our journey the lever controlling the sand-box must be used liberally1 to prevent slipping2 the signal is given1 and at a walking pace we make our way to where the steamer is awaiting us4 ,a gentle application of the brake pulls us up1 and the journey is over4 ,it is difficult to realize1 as the engine stands quietly under the lee of the pier while the driver examines the machinery1 and the fire1 burned low1 throws out a gentle warmth as we stand before it1 that half an hour ago we were tearing along the line at full speed1 while the foot-plate that is now so pleasant to lounge on throbbed beneath us4 ,nothing now remains but to kill time as best we may till the return trip many hours hence4 ,it scarcely promises to be as comfortable as our morning ride1 for the weather has changed--it is blowing half a gale1 and the rain comes down in sheets4 ,our train is timed to start in the small hours1 and the night seems dirty and depressing enough as we make our way for a cup of coffee to the refreshment room1 where a melancholy ,italian sits in sad state eating ,bath buns and drinking brandy4 ,we walk past the train1 laden with miserable sea-sick humanity1 and step on the engine1 which stands in the dark at the end of the platform4 ,time is up1 and we pass from the dim half-light of the station into outer darkness4 ,a blacker night there could hardly be2 looking ahead there is nothing to be seen but one's own reflection in the weather-glass4 ,we are in the midst of obscurity1 which suddenly changes to a rich light as the whistle is opened and we enter a tunnel4 ,the effect is far more striking than in the daytime4 ,the light is more concentrated1 and the mouth of the tunnel we have just entered might be the entrance to ,hades--for there is no telltale spot of light to prove to our senses the existence of any opening at the other end4 ,the sound echoed from the walls and roof has a tremendous quality1 and resolves itself into a grand sort of ,wagnerian rhythm1 making a vast crescendo1 till with a rush we clear the tunnel1 and are once more under the open sky4 ,the pace is increasing1 the steady beat of the engine tells more distinctly on the ear than in the daytime2 the foot-plate is lit up by the glare from the fire-door2 but still there is nothing to be seen ahead but the impenetrable night4 ,looking back1 however1 the scene is very different4 ,the tender and guard's van glow in the light thrown by the fire1 trees and houses by the side of the track stand out sharply for a moment and are then lost to sight1 the light from the carriage windows produces the effect of the wake of a ship seen from the stern4 ,gradually the clouds have rolled away1 leaving the sky clear4 ,the moon is seen fitfully through the whirling steam2 the surrounding country is visible for miles round4 ,the effect produced is unspeakably beautiful4 ,in the mean time let us turn our attention to the working of the engine4 ,in the first place1 let us take note that1 although the engine we are now on1 and that which took us from ,london1 belong to the same type1 their performances are somewhat different4 ,no two engines ever resemble each other1 no matter how carefully they may have been built from the same plan1 neither do any two drivers manage their engines precisely in the same way4 ,we have in this instance an excellent opportunity of comparing two different methods of driving4 ,it is the driver's principal object to get the required amount of work out of his engine with the smallest possible expenditure of coal and water4 ,to obtain this result the steam must be worked expansively1 which is done by placing the valve gear in such a position by means of the lever that the supply of steam to the cylinders is cut off1 as we have stated at the beginning of this article1 before the piston has accomplished its full stroke4 ,there are two ways of controlling the speed of an engine worked1 as all locomotives are worked now1 expansively4 ,you may keep the regulator wide open1 so that there is always a full supply of steam on its way to the cylinders1 in which case you increase or diminish the speed by using the steam more or less expansively through the agency of the lever4 ,or you may work with the same amount of expansion throughout the journey1 and have command of the engine by constantly changing the position of the regulator4 ,there is no doubt that the men who employ the latter method save something by it1 although this would hardly seem to be the opinion of the driver who is bringing us rapidly nearer to ,london1 for unlike the driver whom we accompanied on the daylight journey1 his hand is not often on the regulator4 ,as we rush on past countless signals1 punctual to the minute1 yet always having ample time to slacken speed before we come to the places where the different colored lights cluster thickest1 we are reminded once more how much is required of an express engine-man besides a thorough acquaintance with the machinery he has to control4 ,traveling at night at a great speed1 he must know every inch of the road by heart--where an incline begins and where it ends1 and the exact spot at which every signal along the line may be first sighted4 ,he must have completely mastered the working of the traffic on both the up and down lines1 and1 above all1 must be ready to act with the utmost promptitude should anything go wrong4 ,mr4 ,michael ,reynolds' publications have done much toward enlightening the public on these points1 but we doubt if there are many who really know the amount of toil and danger cheerfully faced by the men on the engine1 who hold their lives in their hands day after day for many years4 ,these thoughts occur to us as we recross the ,thames and pull up at the platform after a thoroughly enjoyable run4--,saturday ,review4 99 99 99 99 99 ,the mucilage on postage stamps may not be unhealthy1 but persons having a good many to affix to letter envelopes1 circulars1 newspapers1 or other wrappers every day1 will consume considerable gum during a year4 ,a less objectionable mode of affixing stamps than the one usually employed is to wet the upper right hand corner of the envelope1 and press the stamp upon it4 ,it will be found to adhere quite as well as if the stamp went through the moistening process4 99 99 99 99 99 ,,erythroxylon4 ,footnote3 ,from an ,ephemeris of ,materia ,medica1 ,pharmacy1 ,therapeutics1 and ,collateral ,information4 ,by ,edward ,e4 ,squibb1 ,m4,d41 ,edward ,h4 ,squibb1 ,s4,b41 ,m4,d41 and ,charles ,f4 ,squibb1 ,a4,b4 ,,coca4 ,the condition of the principal markets of the world for this drug has recently been exceptionally bad4 ,that is1 whether good coca was sought for in the ports of ,central and ,south ,america1 or in ,london1 ,hamburg1 or ,new ,york1 the search1 even without limitation in price1 was almost invariably unsuccessful4 ,not that the drug1 independent of quality1 was scarce1 for hundreds of bales were accessible at all times2 but the quality was so poor as to be quite unfit for use4 ,the samples1 instead of being green and fragrant1 were brown and odorless1 or musty and disagreeable1 at once condemning the lots they represented1 to the most casual observation1 and yet the price was high enough to have represented a good article4 ,the best that could be done by the most careful buyers was to accept occasional parcels1 the best of which were of very inferior quality1 and therefore unfit for medicinal uses1 and these at very high prices4 ,coca is well known to be a very sensitive and perishable drug1 only fit for its somewhat equivocal uses when fresh and green1 and well cared for in packing and transportation4 ,very much like tea in this and other respects1 it should be packed and transported with the same care and pains1 in leaded chests1 or in some equivalent package4 ,it is very well known that tea1 if managed1 transported1 handled1 and sold as coca is1 would be nearly or quite worthless1 and therefore coca managed as the great mass of it is must be nearly all of it comparatively worthless4 ,if used as tea is1 this would probably soon appear2 but when used as a medicine which has been highly extolled and well advertised1 it seems to go on equally well whether of good or bad quality4 ,it is pretty safe to say that nineteen-twentieths of the coca seen in this market within the past two years must be almost inert and valueless1 yet all is sold and used1 and its reputation as a therapeutic agent is pretty well kept up4 ,at least many thousands of pounds of the brown ill-smelling leaf1 and of preparations made from it1 are annually sold4 ,and worse than this1 considerable quantities of a handsome looking green leaf1 well put up and well taken care of1 have been sold and used as coca1 when wanting in nearly all its characteristics4 ,the writer for more than a year past has seen but one or two small lots of moderately good coca1 and in common with other buyers has been obliged to buy the best that could be found to keep up his supply of the fluid extract4 ,almost every purchase has been made on mental protest1 and he has been ashamed of every pound of fluid extract sent out1 from the knowledge that it was of poor quality2 and there seems to be no more prospect of a supply of better quality than there was this time last year1 because so long as an inferior quality sells in such enormous quantities at good prices the demands of trade are satisfied4 ,under this condition of the markets1 the writer has finally decided to give up making a fluid extract of coca1 and has left it off his list1 adopting a fluid extract of tea instead1 as a superior substitute1 for those who may choose to use it1 and regrets that this course was not taken a year ago4 ,the character of coca as a therapeutic agent is not very good4 ,the florid stories of a multitude of travelers and writers1 up to and including the testimony of ,dr4 ,mantegazza1 received a considerable support from so good an authority as ,sir ,robert ,christison1 who reported very definite results from trials made upon himself1 and upon several students under his immediate control and observation2 and his results seem to have led to a very careful and exhaustive series of observations at ,university ,college1 ,london1 by ,mr4 ,dowdeswell4 ,this paper1 published in ,the ,lancet of ,april #bi and ,may #f1 #ahgf1 pp4 #fca and #ffd1 is entitled ,the ,coca ,leaf3 ,observations on the ,properties and ,action of the ,leaf of the ,coca ,plant 7,erythroxylon coca71 made in the ,physiological ,laboratory of ,university ,college1 by ,g4,f4 ,dowdeswell1 ,b4,a4 ,the results of these investigations were absolutely negative1 and at the close of the work the investigator says3 ,without asserting that it is positively inert1 it is concluded from these experiments that its action is so slight as to preclude the idea of its having any value either therapeutically or popularly2 and it is the belief of the writer1 from observation upon the effect on the pulse1 etc41 of tea1 milk and water1 and even plain water1 hot1 tepid1 and cold1 that such things may1 at slightly different temperatures1 produce a more decided effect than even large doses of coca1 if taken at about the temperature of the body4 ,conflicting and contradictory testimony from competent authority is not uncommon in therapeutics1 and the reasons for it are well recognized in the impossibility of an equality in the conditions and circumstances of the investigations1 and hence the general decision commonly reached is upon the principle of averages4 ,there can hardly be a reasonable doubt that coca1 in common with tea and coffee and other similar articles1 has a refreshing1 recuperative1 and sustaining effect upon human beings1 and when well cultivated1 well cured1 and well preserved1 so as to reach its uses of good quality and in good condition1 it is at least equal to good tea1 and available for important therapeutic uses4 ,mr4 ,dowdeswell supposed that he used good coca1 but it is very easy to see that with any amount of care and pains he may have been mistaken in this4 ,had he but used the same parcel of coca that ,sir ,robert ,christison did1 the results of the two observers would be absolutely incomprehensible2 and the results1 in the absence of any testimony on that point1 simply prove that the two observers were using a different article1 though under the same name1 and possibly with the same care in selection4 ,on ,sir ,robert ,christison's side of the question there are many competent observers whose testimony is spread over many years2 while on ,mr4 ,dowdeswell's side there are fewer observers4 ,but there has been no observer on either side whose researches have been anything like so thorough1 so extended1 or so accurate as those of ,mr4 ,dowdeswell4 ,indeed1 no other account has been met with wherein the modern methods of precision have been applied to the question at all2 the other testimony being all rather loose and indefinite1 often at second or third hands1 or from the narratives of more or less enthusiastic travelers4 ,but if ,mr4 ,dowdeswell's results be accepted as being conclusive1 the annual consumption of #dj1jjj1jjj pounds of coca at a cost of #aj1jjj1jjj dollars promotes this substance to take rank among the large economic blunders of the age4#i ,footnote #i3 ,an excellent summing up of the character and history of coca1 from which some of the writer's information has been obtained1 will be found in ,medicinal ,plants1 by ,bentley and ,trimen1 vol4 i41 article #dj4 ,the testimony in regard to the effects of tea1 coffee1 ,paraguay tea1 ,guarana and ,kola nuts1 is all of a similar character to that upon coca4 ,each of these substances seems to have come into use independently1 in widely separated countries1 to produce the same effects1 namely1 to refresh1 renew1 or sustain the physical and mental organism1 and it was a curious surprise to find1 after they had all been thus long used1 that although each came from a different natural order of plants1 the same active principle--namely1 caffeine--could be extracted in different proportions from all4 ,it is now still more curious1 however1 to find that for centuries another plant1 namely coca1 yielding a different principle1 has been in use for similar purposes1 the effects of which differ as little from those of tea1 coffee1 etc41 as these do among themselves4 ,yet cocaine is chemically very different from caffeine1 simply producing a similar physiological effect in much smaller doses4 ,all these substances in their natural condition seem to be identical in their general physiological effect1 but idiosyncrasy1 or different individual impressibility or sensitiveness1 causes a different action1 as well in quality as in degree from the different substances1 upon some persons4 ,in order to throw a little additional light on the comparative activity of the principal individuals of this group of substances1 the following trials were made4 ,it is generally admitted1 and is probably true1 that the same power in these agents which refreshes1 recuperates1 and sustains in the condition which needs or requires such effects also counteracts the tendency to sleep1 or produces wakefulness when a tendency to sleep exists2 and1 therefore1 if a tendency or disposition to sleep could be prevented by these agents1 this tendency might be used as a measure of their effects when used in varying quantities1 and thus measure the agents against each other for dose or quantitative effect4 ,in this way the proposition is to first measure coca against tea1 then coffee against guarana1 and finally to compare the four agents1 using pure caffeine as a kind of standard to measure by4 ,an opportunity for such trials occurred in a healthy individual sixty-five years old1 not habituated to the use of either tea1 coffee1 tobacco1 or any other narcotic substances1 of good physical condition and regular habits1 and not very susceptible or sensitive to the action of nervines or so-called anti-spasmodics4 ,quantities of preparations of valerian1 asafoetida1 compound spirit of ether1 etc41 which would yield a prompt effect upon many individuals seem to have little or no effect upon him1 nor do moderate quantities of wines or spirits stimulate him4 ,that is to say1 he has not a very impressible nervous organization1 is not imaginative1 nor very liable to accept results on insufficient or partial evidence4 ,fully occupied with work1 both physical and mental in due proportion1 for more than ten hours every secular day1 when evening comes he finds himself unable to read long on account of a drowsiness supposed to be of a purely physiological character4 ,with a full breakfast at about #g3cj1 a full dinner at about #b3cj1 and a light evening meal about #g1 and no stimulants1 or tea1 or coffee at any time1 he finds1 as a matter of not invariable but general habit1 that by half past #h drowsiness becomes so dominant that it becomes almost impossible1 and generally impracticable1 to avoid falling asleep in his chair while attempting to read1 even though ordinary conversation be carried on around him4 ,the first trial to combat or prevent this drowsiness was made with caffeine4 ,the first specimen used was a very beautiful article made by ,merck of ,darmstadt1 and after that by pure specimens made for the purpose1 the two kinds being found identical in effect4 ,commencing with a one grain dose at about #f3cj ,p4,m41 on alternate evenings1 leaving the intermediate evenings in order to be sure that the nightly tendency still persisted1 and increasing by half a grain each alternate evening1 no very definite effect was perceived1 until the dose reached #b grains1 and this dose simply rendered the tendency to sleep resistible by effort4 ,after an interval of three evenings1 with the tendency to sleep recurring with somewhat varying force each evening1 a dose of #c grains was taken1 the maximum single dose of the ,german ,pharmacopoeia4 ,this gave a comfortable evening of restedness1 without sleep or any very strong tendency to it until ten o'clock4 ,without anything to counteract sleep1 the rule was to read with difficulty by nine1 without much comprehension by quarter past nine1 and either be asleep or go to bed by half past nine4 ,the #c grain dose of caffeine repeatedly obviated all this discomfort up to ten o'clock1 but did not prevent the habitual1 prompt1 and sound sleep1 from the time of going to bed till morning4 ,this was the model established1 upon and by which to measure all the other agents1 and they were never taken nearer than on alternate evenings1 with occasional longer intervals1 especially when the final doses of record were to be taken4 ,the next agent tried in precisely this same way was coca2 and knowing that the quality of that which was attainable was very low1 the commencing dose of the leaf in substance was #b drachms1 or about #h grammes4 ,this gave no very definite effect1 but #b drachms did give a definite effect1 and a subsequent dose of #b fluid drachms of a well made fluid extract of coca gave about the same effect as #b grains of caffeine4 ,three fluid drachms of the fluid extract were about equivalent to #c grains of caffeine4 ,both the coca used and the fluid extract were then assayed by the modern methods1 for the proportion of the alkaloid they contained4 ,the only assays of coca that could be found conveniently were those of ,dr4 ,albert ,niemann1 of ,goslar1 given in the ,american ,journal of ,pharmacy1 vol4 xxxiii41 p4 #bbb1 who obtained #j4be per cent42 and of ,prof4 ,jno4 ,m4 ,maisch1 in the same volume of the same journal1 p4 #dif1 who obtained #d grains of alkaloid from #a1ejj grains of coca1 which is also about a quarter of one per cent4 ,these assays were1 however1 very old1 and made by the old process4 ,the process used by the writer was the more modern one of ,dragendorff slightly modified4 ,it was as follows3 ,thirty grammes of powdered coca1 thoroughly mixed in a mortar with #h grammes of caustic magnesia1 were stirred into #bjj c4c4 of boiling water1 and the mixture boiled for ten minutes4 ,the liquid was filtered off1 and the residue percolated with about #fj c4c4 of water4 ,it was then again stirred into #aej c4c4 of boiling water1 and was again boiled and percolated until apparently thoroughly exhausted4 ,the total liquid1 amounting to more than #fjj c4c41 was evaporated on a water-bath1 commencing with the weaker portions1 so that the stronger ones might be exposed to the heat for the shortest time1 until reduced to about #bj c4c4 ,this liquid extract was transferred to a flask1 and vigorously shaken with #ej c4c4 of strong ether4 ,the ether was poured off1 as closely as practicable1 into a tared capsule1 where it was allowed to evaporate spontaneously4 ,a second and third portion of ether1 each of #ej c4c41 were used in the same way1 and the whole evaporated to dryness in the capsule4 ,a scanty1 greenish1 oily residue was left in the capsule1 in which there was no appearance of a crystallized alkaloid4 ,the capsule and contents were then weighed and the weight noted4 ,the oily residue was then repeatedly washed with small quantities of water1 until the washings no longer affected litmus-paper4 ,the oily matter adhered to the capsule during this process1 no part of it coming off with the washing1 and at the end of the washing the capsule and contents were again dried and weighed1 and the weight subtracted from the original weight4 ,the difference was taken as the alkaloid cocaine1 and it amounted to #j4jgg grm41 equal to #j4bf per cent4 ,several preliminary assays were made in reaching this method4 ,some authorities recommend the very finely powdered mixture of coca and magnesia1 or coca and lime1 to be at once exhausted with ether4 ,others recommend that the mixture be made into a paste with water1 and after drying on a water-bath that it be then exhausted with ether4 ,this is better1 but neither of these methods were satisfactory4 ,finally1 #cj c4c4 of a well made fluid extract of the same coca was thoroughly mixed with #h grms4 of caustic magnesia in a capsule1 and the mixture dried on a water-bath and powdered4 ,this powder was then exhausted1 one part by ether and the other part by chloroform1 exactly as in the method given1 both parts giving very slightly higher results4 ,as a check upon the results1 the solution of alkaloid washed out was titrated with normal solution of oxalic acid4 ,from all this it would appear that this inferior coca of the markets1 or rather the best that can be selected from it1 yields about the same proportion of the alkaloid as was obtained by ,niemann and ,maisch1 but it has been shown that1 by the older processes of assay used by them1 much of the alkaloid was probably lost or destroyed1 and that much better results are generally obtained by the modern process4 ,now1 since #c drachms of this coca1 or three fluid drachms of its fluid extract1 gave the same physiological1 or perhaps therapeutical1 effect as #c grains of caffeine1 and as the #c drachms contained about #j4de grain of cocaine1 it follows that cocaine is about #f4e times more effective than caffeine2 but it also follows that the coca accessible1 and even the very best coca1 contains very much less of its alkaloid than those articles which yield caffeine do of that principle4 99 99 99 99 99 ,,the ,,melloco4 ,,ullucus ,,tuberosa4--,early last year two tubers of this plant were received at ,kew from ,caracas1 and from out of doors in a prepared bed in ,june4 ,the result of this experiment1 together with a few particulars as to the esculent properties of the tubers1 may be worth recording1 as ,i believe several gardeners1 among them being the ,messrs4 ,sutton1 have obtained tubers of the ,ullucus from ,kew with a view to giving it a trial4 ,the two ,caracas tubers mentioned above were as large as hens' eggs1 rather longer1 and somewhat flattened2 the skin was red1 as in some potatoes4 ,these1 when placed in heat1 rapidly developed shoots1 which were removed as soon as they were strong enough to form cuttings2 in this way about a hundred sturdy young plants were obtained and made ready for planting out of doors in ,june4 ,they were planted in a light1 sandy1 well manured soil in a position exposed to full sunshine4 ,here they grew quickly1 forming by the middle of ,august tufts of shoots and leaves one foot across4 ,they were earthed up as for potatoes1 and the strongest shoots were pegged down and partly covered with soil1 though the latter proved unnecessary4 ,at this time there were no tubers nor any signs of them4 ,on again examining the plants in ,september 7about the middle71 we were surprised to find no tubers had yet been formed4 ,the plants were now very strong1 and it was therefore concluded that instead of forming tubers the strength of the plants had run to leaves4 ,we gave them up1 no further notice being taken of them till the frost came1 when on perceiving that a frost of four or five degrees did not injure the foliage1 we again examined the plants1 and found an abundant crop of tubers just below the surface of the soil1 and varying in size from that of peas to pigeons' eggs4 ,the plants were left till the haulms had been destroyed by cold1 after which the tubers were gathered4 ,on cooking some of the larger ones by boiling for half an hour1 we found them still rather hard1 and with a flavor of potatoes1 almost concealed under a strong earthy taste1 quite disagreeable and soap-like4 ,considering how short a time these tubers had had to grow in it is not improbable that their hardness and disagreeable taste were owing to their being unripe2 no doubt young1 green potatoes 7these ,ullucus tubers were partly green7 would be quite as nauseous as these were4 ,illustration3 ,,melloco ,,tubers4 ,we are told that the ,ullucus is extensively cultivated in ,peru and ,bolivia1 in the elevated regions where the common potato also thrives1 and with which the ,ullucus is equally popular as a tuber-yielding plant4 ,in the ,gardeners' ,chronicle for #ahdh1 p4 #hfb1 ,mr4 ,j4,b4 ,pentland stated that the ,ullucus is planted in ,july or ,august1 the seed employed being generally the smaller tubers1 unfit for food1 and is gathered in during the last week of ,april4 ,these two periods of the year are the spring and autumn in the southern hemisphere4 ,the mode of cultivation is in drills1 into which the root is dropped1 with a little manure4 ,the climate1 even during the summer season1 is severe1 scarcely a night passing over without the streams being frozen over1 the sky being in general cloudless at all periods of the year except during the rainy season 7,december to ,march74 ,mean temperature about #di4 ,this information seems to support the view formed of this plant from its behavior at ,kew last year1 namely1 that the tubers are formed on the approach of cold weather1 and that1 so long as the weather is warm and bright1 leaves only are developed4 ,plants grown in houses where the temperature has not been allowed to fall below #ej in winter did not form any tubers1 although they were in good health4 ,we found no tubers on the plants grown out of doors till some time after the return of cold1 wet weather4 ,it seems likely that this plant does not develop tubers unless its existence is threatened by cold2 at all events1 such a conclusion seems reasonable from the above statements4 ,possibly a wet and rather cold autumn would be favorable to this plant and the production of its tubers--such a season1 for instance1 as would be most unfavorable for the common potato4 ,it would be worth while testing the ,ullucus for low and cold situations where the potato would not thrive4 ,there is not much probability of the former ever proving a substitute for or even a rival to the potato1 at least in this country2 but there is room for another good esculent1 and the ,ullucus is prolific enough1 hardy enough1 and1 we suppose1 when properly grown1 palatable enough to be worthy a trial4 ,in the ,gardeners' ,chronicle for #ahdh1 p4 #hbh1 will be found a most interesting detailed account of experiments made with this plant in ,france by ,m4 ,louis ,vilmorin4--,w4 ,waston1 ,kew2 ,the ,gardeners' ,chronicle4 99 99 99 99 99 ,a catalogue1 containing brief notices of many important scientific papers heretofore published in the ,,supplement1 may be had gratis at this office4 99 99 99 99 99 ,,the ,,scientific ,,american ,,supplement4 ,,published ,,weekly4 ,,terms ,,of ,,subscription1 #e ,a ,,year4 ,sent by mail1 postage prepaid1 to subscribers in any part of the ,united ,states or ,canada4 ,six dollars a year1 sent1 prepaid1 to any foreign country4 ,all the back numbers of ,,the ,,supplement1 from the commencement1 ,january #a1 #ahgf1 can be had4 ,price1 #aj cents each4 ,all the back volumes of ,,the ,,supplement can likewise be supplied4 ,two volumes are issued yearly4 ,price of each volume1 #b4ej1 stitched in paper1 or #c4ej1 bound in stiff covers4 ,,combined ,,rates--,one copy of ,,scientific ,,american and one copy of ,,scientific ,,american ,,supplement1 one year1 postpaid1 #g4jj4 ,a liberal discount to booksellers1 news agents1 and canvassers4 ,,munn ,,co41 ,publishers1 #cfa ,broadway1 ,new ,york1 ,n4,y4 99 99 99 99 99 ,,patents4 ,in connection with the ,,scientific ,,american1 ,messrs4 ,,munn ,co4 are ,solicitors of ,american and ,foreign ,patents1 have had #dj years' experience1 and now have the largest establishment in the world4 ,patents are obtained on the best terms4 ,a special notice is made in the ,,scientific ,,american of all ,inventions patented through this ,agency1 with the name and residence of the ,patentee4 ,by the immense circulation thus given1 public attention is directed to the merits of the new patent1 and sales or introduction often easily effected4 ,any person who has made a new discovery or invention can ascertain1 free of charge1 whether a patent can probably be obtained1 by writing to ,,munn ,co4 ,we also send free our ,hand ,book about the ,patent ,laws1 ,patents1 ,caveats1 ,trade ,marks1 their costs1 and how procured4 ,address ,,munn ,,co41 #cfa ,broadway1 ,new ,york4 ,branch ,office1 cor4 ,f and #gth ,sts41 ,washington1 ,d4,c4