,illustration ,,scientific ,,american ,,supplement ,,no4 #dhc ,,new ,,york1 ,,april #d1 #ahhe ,scientific ,american ,supplement4 ,vol4 ,,xix1 ,no4 #dhc4 ,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 ,,chemistry ,,and ,,metallurgy4--,the ,determination of ,graphite in ,minerals4--,by ,j4,b4 ,,mackintosh4 ,sulphocyanide of ,potassium4 ,sugar ,nitro-glycerine4 ,on ,remelting of ,cast ,iron4 ,the ,hardness of ,metals4 ,,ii4 ,,engineering1 ,,etc4--,the ,jet ,ventilator4 #d figures4 ,feeding ,boilers at the ,bottom4 #b figures4 ,the ,honigmann ,fireless ,engine4--,the fireless working of steam engines by means of a solution of hydrate of soda4--,with several figures and diagrams4 ,simple ,methods of ,calculating ,stress in ,girders4--,by ,,ch4 ,,lean4--,with full page of illustrations4 ,a ,spring ,motor4 ,steam ,yachts4 ,,iii4 ,,technology4--,foucault's ,apparatus for ,manufacturing ,illuminating ,gas and ,hydrogen4 #b figures4 ,the ,circle ,divider4 ,soluble ,glass4--,process of manufacture4--,use4 ,iron ,printing and ,microscopic ,photography4--,formulas for printing solutions4--,compound negatives4 ,practical ,directions for ,making ,lantern ,transparencies4--,by ,t4,n4 ,,armstrong4 ,casting ,chilled ,car ,wheels4 #f figures4 ,,iv4 ,,electricity1 ,,etc4--,electricity and ,prestidigitation4 #b figures4 ,portable ,electric ,safety ,lamp4 #f figures4 ,the ,electric ,discharge and ,spark ,photographed ,directly without an ,objective4 #f engravings4 ,v4 ,,physics1 ,,etc4--,the ,true ,constant of ,gravity4 ,origin of ,thunder ,storms4 ,physics without ,apparatus4--,manufacture of illuminating gas4--,elasticity of bodies4 #b figures4 ,scientific ,amusements4--,dance of electrified puppets4--,silhouette portraits4 #b figures4 ,a ,sunshine ,recorder4 #b figures4 ,,vi4 ,,medicine1 ,,hygiene1 ,,etc4--,how ,cholera is ,spread4 ,sulphurous ,acid and ,sulphide of ,carbon as ,disinfecting ,agents4--,methods of burning the same4 ,,vii4 ,,miscellaneous4--,improvised ,toys4--,with numerous illustrations4 ,the olian ,harp4--,kircher's harp1 made in #aeeh4--;,frost and ,kastner's harp4--,manner of making the harps4 #d figures4 ,how to ,break a ,cord with the ,hands4 #a figure4 ,an ,aquatic ,velocipede for ,duck ,hunting4 #b engravings4 ,skeleton of a ,bear ,found in a ,cave in ,styria1 ,austria4 ,,viii4 ,,biography4--,theodor ,billroth1 ,prof1 of ,surgery at ,vienna4--,with portrait4 99 99 99 99 99 ,,acknowledgment4 ,the illustrations and descriptions we give this week1 entitled ,how to ,break a ,cord1 ,prestidigitation1 ,circle ,divider1 ,sulphurous ,acid1 ,production of ,gas1 ,aquatic ,velocipede1 ,several ,toys1 ,scientific ,amusements1 are from our excellent contemporary ,la ,nature4 99 99 99 99 99 ,,theodor ,,billroth1 ,,professor ,,of ,,surgery ,,at ,,vienna4 ,the well known surgeon1 ,theodor ,billroth1 was born on the island of ,rgen in #ahbi4 ,he showed great talent and liking for music1 and it was the wish of his father1 who was a minister1 that he should cultivate this taste and become an artist2 but the great masters of medicine1 ,johannes ,mueller1 ,meckel v4 ,hemsbach1 ,r4 ,wagner1 ,traube1 and ,schnlein1 who were ,billroth's instructors at ,greifswald1 ,gttingen1 and ,berlin1 discovered his great talent for surgery and medicine1 and induced him to adopt this profession4 ,it was particularly the late ,prof4 ,baum who influenced ,billroth to make surgery a special study1 and he was ,billroth's first special instructor4 ,in #aheb ,billroth received his degree as doctor at the ,university of ,berlin4 ,after traveling for one year1 and spending part of his time in ,vienna and ,paris1 he was appointed assistant in the clinique of ,b4 von ,langenbeck1 ,berlin4 ,at this time he published his works on pathological histology 7,microscopic ,studies on the ,structure of ,diseased ,human ,tissues7 which made him so well known that he was appointed a professor of pathology at ,greifswald in #aheh4 ,mr4 ,billroth did not accept that call1 and was appointed professor of surgery at ,zurich in #ahfj1 and during that time his wonderful operations gave him a world-wide reputation4 ,in #ahfg the medical faculty of the ,vienna ,university concluded to appoint ,billroth as successor to ,prof4 ,schuh1 which position he still fills4 ,illustration3 ,,theodor ,,billroth4 ,billroth is a master of surgical technique1 and his courage and composure increase with the difficulty of the operation4 ,he always makes use of the most simple apparatus and instruments1 and follows a theoretically scientific course which he has never left since he adopted surgery as a profession1 and by which he has directed surgery into entirely new channels4 ,he has given special attention to the study of the healing of wounds1 the development of swellings and tumors1 and the treatment of wounds in relation to decomposition and the formation of proud flosh4 ,he has had wonderful success in performing plastic operations on the face1 such as the formation of new noses1 lips1 etc41 from flesh taken from other parts of the body or from the face4 ,although ,billroth devoted much of his time to the solution of theoretical problems1 he has also been very successful as an operator4 ,he has removed diseased larynxes1 performed dangerous goiter operations1 and successfully removed parts of the oesophagus1 stomach1 and intestines4 ,billroth has been very careful in the selection of his scholars1 and many of them are now professors of surgery and medicine in ,germany1 ,belgium1 and ,austria4 ,they all honor and admire him1 his courage1 his character1 his humane treatment of the sick and suffering1 arid his amiability4 ,the accompanying portrait is from the ,illustrirte ,zeitung4 99 99 99 99 99 ,,how ,,cholera ,,is ,,spread4 ,,dr4 ,,john ,c4 ,,peters1 of this city1 in a recent contribution to the ,medical ,record1 gives the following interesting particulars3 ,i have read many brilliant essays of late on these topics1 but not with unalloyed pleasure1 for ,i believe that many writers have fallen into errors which it is important to correct4 ,no really well informed person has believed for a long time that carbolic alcohol will destroy the cholera poison2 but many fully and correctly believe that real germicides will4 ,it has been known since #ahgb that microbes1 bacilli1 and bacteria could live in very strong solutions of carbolic alcohol1 and that the dilute mineral acids1 tannin1 chloride1 corrosive sublimate1 and others would kill them4 ,in #ahhc cholera did not arise alone in ,egypt from filth1 but from importation4 ,it did not commence at ,alexandria1 but at ,damietta1 which is the nearest ,nile port to ,port ,said1 which is the outlet of the ,suez ,canal4 ,there were #cg1ejj deaths from cholera in the ,bombay ,presidency in #ahhc4 ,bombay merchants came both to ,port ,said and ,damietta to attend a great fair there1 to which at least #ae1jjj people congregated1 in addition to the #ce1jjj inhabitants4 ,the barbers who shave and prepare the dead are the first registrars of vital statistics in many ,egyptian towns1 and the principal barber of ,damietta was among the first to die of cholera2 hence all the earliest records of deaths were lost1 and the more fatal and infective diarrhoeal cases were never recorded4 ,next the principal ,european physician of ,damietta had his attention called to the rumors of numerous deaths1 and investigated the matter1 to find that cases of cholera had occurred in ,may1 whereas none had been reported publicly until ,june #ba4 ,a zadig1 or canal1 runs through ,damietta from one branch of the ,nile to another1 and this is the principal source of the water supply4 ,mosques and many houses are on the banks of this canal1 and their drainage goes into it4 ,every mosque has a public privy1 and also a tank for the ablution1 which all good ,mohammedans must use before entering a holy place4 ,there was1 of course1 great choleraic water contamination1 and a sudden outburst of cholera took place4 ,the #ae1jjj people who came to the fair were stampeded out of ,damietta1 together with about #aj1jjj of the inhabitants1 who carried the disease with them back into ,egypt4 ,then only was a rigid quarantine established1 and a cordon put round ,damietta to keep everybody in1 and let no one go out1 neither food1 medicines1 doctors1 nor supplies of any kind4 ,such is nearly the history of every town attacked in ,egypt in #ahhc4 ,when the pestilence had been let out en masse1 severe measures were taken to keep it in ,cairo1 for up the ,nile was attacked long before ,alexandria suffered4 ,this cholera broke out1 as it almost always does in ,egypt1 when the river ,nile is low and the water unusually bad4 ,it disappeared like magic1 as it always does in ,egypt1 when the ,nile rises and washes all impurities away4 ,there had been little or no cholera in ,egypt since #ahfe1 and there had often been as much filth as in #ahhc4 ,it has never become endemic there1 as it is a rainless country and generally too dry for the cholera germ to thrive4 ,marseilles had a small outbreak of cholera in the fall of #ahhc1 probably derived from ,egypt1 which she carefully concealed4 ,in addition1 cholera was also brought to ,toulon from ,tonquin by the ,sarthe and other vessels4 ,toulon concealed her cholera for at least seventeen days1 and did not confess it until it had got such headway that it could no longer be concealed4 ,at least twenty thousand ,italians fled from ,toulon and ,marseilles1 and others were brought away in transports by the ,italian government4 ,rome refused to receive any fugitives2 ,genoa and ,naples welcomed them4 ,there were at least three large importations into ,naples4 ,the outbreak in ,genoa was connected with washing soiled cholera clothes in one of the principal water supplies of the city1 and ,naples has many privy pits and surface wells4 ,these privies1 or pozzis1 in the poorer parts of many ,italian towns1 are in the yards or cellars1 and are so arranged that when they overflow1 the surplusage is carried through drains or gutters into the streets4 ,in the lowest parts of ,toulon there were no privies at all1 and the people emptied their chamberpots into the streets every morning4 ,this flowed down toward the harbor1 which is almost tideless4 ,toulon always has much typhoid fever from this cause2 but no cholera unless it is imported4 ,the great outbreaks of cholera in ,paris in #ahcb1 #ahdh1 #ahed1 and #ahfe have been explained at last by ,dr4 ,marcy4 ,the canal de l',ourcq is one of the principal water sources of ,paris4 ,the market boats or vessels upon it and at ,la ,villette are so numerous that ,marseilles and ,havre alone outrank it in shipping4 ,the parts of ,paris which are always most severely attacked with cholera1 and where the most typhoid fever prevails1 are supplied with this water1 into which not only all the filth of the boats goes1 but many sewers empty4 ,i agree with all that is generally said about civic filth favoring the spread of cholera1 but it does not generate1 but only supplies the pabulum for the germs4 ,i believe as long as the ,croton water is kept pure there can be no general outbreak of cholera in ,new ,york1 only isolated cases1 or at most a few in each house1 and those only into which diarrhoeal cases come1 or soiled clothes are brought2 that it will not spread even to the next house1 and that there are no pandemic waves of cholera4 ,i think it impossible to pump ,new ,york dock water into the sewers1 and that it would be very injurious if it could be done4 ,almost all our sewers empty into the docks1 and the water there is of the foulest kind4 ,i do not believe in a long quarantine1 and think that of the ,dutch is the best4 ,they only detained the sick1 but took the addresses of all who were let through1 or kept back all their soiled clothing1 which they had washed1 disinfected1 and sent after their owners in three days4 ,st4 ,louis still has #bj1jjj privy pits and as many surface wells4 ,the importation of cholera into ,st4 ,louis is well proved for #ahcb1 #ahdh1 #ahdi1 #ahed1 #ahff1 and #ahgc4 ,those who used surface well water suffered much more than those who drank ,mississippi water1 however foul that may have been4 ,the history of cholera in ,st4 ,louis has been better and more accurately written up quite lately by ,mr4 ,robert ,moore1 civil engineer1 than that of any city in this country4 ,he has kindly given me maps of the city1 with every case marked down1 with street and number1 for all the epidemic4 ,hypodermic injections of atropine and morphine have failed sadly in many cases4 ,subcutaneous injections of large quantities of salt and water1 with some soda1 and large rectal injections of tannin and laudanum have been very successful in ,italy4 ,if there is plenty of acid gastric juice in the stomach1 the cholera poison and microbes may be swallowed with impunity4 ,the worst cases of cholera are produced by drinking large quantities of cholera contaminated water1 when the stomach is empty and alkaline4 ,i think it probable that large quantities1 as much as the thirst requires1 of a weak acid water will prove very beneficial in cholera4 ,water slightly acidulated with sulphuric1 nitric1 or muriatic acid will probably be the best1 but it is hoped that phosphoric1 acetic1 and lactic acids will prove equally good4 ,lemon juice and vinegar are merely acetates and citrates of potash1 and are not as good4 99 99 99 99 99 ,it seems that the offensive smells noticed in the ,english ,houses of ,parliament last session have been traced to their source4 ,it is found that the main sewer of the ,house of ,commons is very large and out of all proportion to the requirements1 is of two different levels1 and discharges into the street sewer within eighteen inches of the bottom of the latter drain4 ,there is thus a constant backflow of sewage4 ,another revelation is that the drain connected with the open furnace in the ,clock ,tower1 for the purpose of ventilation1 is hermetically closed at its opposite end4 99 99 99 99 99 ,,sulphurous ,,acid ,,and ,,sulphide ,,of ,,carbon4 ,much attention has been paid in recent times to disinfecting agents1 and among these sulphurous acid and sulphide of carbon must be placed in the list of the most efficient4 ,mr4 ,alf4 ,riche has recently summed up in the ,journal de ,pharmacie et de ,chimie the state of the question as regards these two agents1 and we in turn shall furnish a few data on the subject in taking the above named scientist as a guide4 ,mr4 ,dujardin ,beaumetz some time ago asked ,messrs4 ,pasteur and ,roux's aid in making some new experiments on the question1 and has made known the result of these to the ,academy of ,medicine4 ,at the ,cochin ,hospital he selected two rooms of #c1ecj cubic feet capacity located in wooden sheds4 ,the walls of these rooms1 which were formed of boards1 allowed the air to enter through numerous chinks1 although care had been taken to close the largest of these with paper4 ,in each of the rooms were placed a bed1 different pieces of furniture1 and fabrics of various colors4 ,bromine1 chlorine and sulphate of nitrosyle were successively rejected4 ,three sources of sulphurous acid were then experimented with1 viz41 the burning of sulphur1 liquefied sulphurous acid1 and the burning of sulphide of carbon4 ,the rooms were closed for twenty-four hours1 and tubes containing different proto-organisms1 and particularly the comma bacillus made known by ,koch1 were placed therein1 along with other tubes containing vaccine lymph4 ,after each experiment these tubes were carried to ,mr4 ,pasteur's laboratory and compared with others4 ,illustration3 ,,fig4 #a4--;,,burner ,,for ,,sulphur4 ,the process by combustion of sulphur is the simplest and cheapest4 ,to effect such combustion1 it suffices to place a piece of iron plate upon the floor of the room1 and on this to place bricks connected with sand1 or1 what is better1 to use a small refractory clay furnace 7as advised by ,mr4 ,pasteur71 of oblong form1 #h inches in width by #aj in length1 and having small apertures in the sides in order to quicken combustion4 ,in order to obtain a complete combustion of the flowers of sulphur1 it is necessary to see to it that the burning is effected equally over its entire surface1 this being easily brought about by moistening the sulphur with alcohol and then setting fire to the latter4 ,through the use of this process a complete and absolute combustion has been obtained of much as from #ah to #bj grains of sulphur per cubic foot4 ,in the proportion of #h grains to the cubic foot1 all the different culture broths under experiment were sterilized save the one containing the bacteria of charbon4 ,as for the vaccine virus1 its properties were destroyed4 ,this economical process presents but two inconveniences1 viz41 the possibility of fire when the furnace is badly constructed1 and the alteration of such metallic objects as may be in the room4 ,in fact1 the combustion of sulphur is attended with the projection of a few particles of the substance1 which form a layer of metallic sulphide upon copper or iron objects4 ,illustration3 ,,fig4 #b4--;,,ckiandi ,,bey',s ,,apparatus ,,for ,,burning ,,carbon ,,sulphide4 ,the use of liquid sulphurous acid in siphons does not offer the same inconveniences4 ,these siphons contain about one and a half pounds of sulphurous acid4 ,the proportion necessary to effect the sterilization of the culture broths is one siphon per #gjf cubic feet4 ,in such a case the modus operandi is as follows3 ,in the middle of the room is placed a vessel1 which is connected with the exterior by means a rubber tube that passes through a hole in the door4 ,after the door has been closed1 it is only necessary to place the nozzle of the siphon in the rubber tube1 and to press upon the lever of the siphon valve1 to cause the liquid to pass from the siphon to the interior of the vessel4 ,the evaporation of the liquid sulphurous acid proceeds very rapidly in the free air4 ,this process is an exceedingly convenient one2 it does away with danger from fire1 and it leaves the gildings and metallic objects that chance to be in the room absolutely intact4 ,finally1 the acid's power of penetration appears to be still greater than that which is obtained by the combustion of sulphur4 ,it has but one drawback1 and that is its high price4 ,each siphon is sold to the public at the price of one dollar4 ,to municipalities using sulphurous acid in this form the price would be reduced to just one-half that figure4 ,it will be seen1 then1 that for a room of #c1ecj cubic feet capacity the cost would be #e4jj or #b4ej4 ,the combustion of sulphide of carbon furnishes an abundance of sulphurous acid1 but has hitherto been attended with danger4 ,this1 however1 has recently been overcome by the invention of a new burner by ,mr4 ,ckiandi ,bey4 ,the general arrangement of this new apparatus is shown in ,figs4 #b and #c4 ,mr4 ,ckiandi's burner consists of an external vessel1 ,a ,b ,c ,d4 of tinned copper1 containing a vessel1 ,i ,h ,e ,f1 to the sides of which are fixed three siphons1 ,r1 ,s4 ,illustration3 ,,fig4 #c4--,,section ,,of ,,the ,,apparatus4 ,to operate the burner1 we place the cylindrical tube1 ,k ,l ,m ,n1 in the inner vessel1 and pour sulphide of carbon into it up to the level aa4 ,this done1 we fill the external vessel with water up to the level bb4 ,thanks to the siphons1 the water enters the inner vessel1 presses the sulphide of carbon1 which is the heavier1 and causes it to rise in the tube up to the level a'a'1 where it saturates a cotton wick1 which is then lighted4 ,the upper end of the tube is surmounted with a chimney1 ,,pq4 which quickens the draught4 ,the combustion may be retarded or quickened at will by causing the level bb of the water to rise or lower4 ,the burner is placed in the room to be disinfected1 which1 after the wick has been lighted1 is closed hermetically4 ,when all the sulphide is burned it is replaced by water1 and the lamp goes out of itself4 ,the combustion proceeds with great regularity and without any danger4 ,it takes about five and a half pounds for a room of #c1ejj cubic feet capacity4 ,the process is sure and quite economical1 since sulphide of carbon is sold at about five cents per pound1 which amounts to #be cents for a room of #c1ejj cubic feet capacity4 ,the burner costs ten dollars1 but may be used for an almost indefinite period4 ,the process of producing sulphurous acid by the combustion of sulphide of carbon is1 as may be seen1 very practical and advantageous4 ,it does not affect metallic objects1 and it furnishes a disinfecting gas continuously1 slowly1 and regularly4 ,mr4 ,ckiandi's burner may also be applied in several industries4 ,it is capable of rendering great services in the bleaching of silk and woolen goods1 and it may also be used for bleaching sponges1 straw hats1 and a number of other objects4--,la ,nature4 99 99 99 99 99 ,,the ,,determination ,,of ,,graphite ,,in ,,minerals4 ,by ,j4,b4 ,,mackintosh4 ,in many instances the accurate determination of the amount of graphite present in a rock has proved a rather troublesome problem4 ,the first thought which naturally suggests itself is to burn the graphite and weigh the carbonic acid produced2 but in the case of the sample which led me to seek for another method1 this way could not be employed1 for the specimen had been taken from the surface1 and was covered and penetrated by vegetable growths which could not be entirely removed mechanically4 ,add to this the fact of the presence of iron pyrites and the probable occurrence of carbonates in the rock1 and it will be at once seen that no reliance could be placed on the results obtained by this suggested method4 ,as the problem thus resolved itself into finding a way by which all interfering substances could be destroyed without affecting the graphite1 it at once occurred to me to try the effect of caustic potash4 ,i melted a few pieces of potash in a silver crucible until it had stopped spitting and was in quiet fusion4 ,i then transferred the weighed sample to the crucible1 the melted potash in which readily wetted the graphite rock4 ,the mass was then gently heated1 and occasionally stirred with a piece of silver wire4 ,the heat never need be much above the melting point of the potash1 though toward the last ,i have been in the habit of raising the temperature slightly1 to insure the complete decomposition of the melt4 ,when the decomposition is complete1 which can be known by the complete absence of gritty particles1 the crucible is cooled and then soaked out in cold water4 ,this is very quickly accomplished1 and we then see that we have an insoluble residue of graphite and a flocculent precipitate of lime1 magnesia1 iron hydrate1 etc41 while the organic matters have disappeared4 ,the sulphides of iron1 etc41 have given up their sulphur to the potash1 and everything except the graphite has suffered some change4 ,the solution is now filtered through a weighed ,gooch crucible1 the residue washed a few times with water1 and then treated with dilute hydrochloric acid 7followed by ammonia to remove any silver taken up from the crucible71 which will dissolve all the constituents of the residue except the graphite1 and after washing will leave the latter free and in a condition of great purity4 ,as evidence of the accuracy of the method1 ,i subjoin the results ,i obtained on a sample whose gangue was free from all organic and other impurities1 consisting chiefly of quartz3 ,new ,method4 ,combustion in ,oxygen1 ,weighing ,,co#b4 #ae4ea #ae4ed ,it is plain that such a result leaves nothing to be desired for the accuracy of the method1 while1 as regards time and trouble1 the advantage lies on the side of the new method4 ,i have completed a determination in less than two hours from the start1 and did not hurry myself over it in any degree4 ,fine pulverization of the sample is not essential1 and in fact is rather detrimental1 as the graphite1 when fine1 is more difficult to wash without loss4 ,when operating on a coarse sample more time is necessarily taken1 but the resulting graphite shows the manner of occurrence better1 whether in scales or in the amorphous form4 ,in consulting the literature bearing on the subject1 ,i cannot find any mention of this method employed as an analytical process2 it has1 however1 been previously described as a commercial method for the purification of graphite1#a and ,i understand has been tried on a small scale in this country4 ,the method1 though inexpensive1 yet seems to have been abandoned for some reason1 and ,i am not aware that it is now employed anywhere4--,sch4 ,mines ,quarterly4 ,footnote #a3 ,schloffel1 ,zeitschrift der ,k4,k4 geolog4 ,reichanstalt1 #ahff1 p4 #abf4 99 99 99 99 99 ,,sulphocyanide ,,of ,,potassium4 ,the elements of cyanogen1 combined with sulphur1 form a salt radical1 sulphocyanogen1 ,c#b,,ns#b1 which is expressed by the symbol ,csy4 ,the sulphocyanide of potassium1 ,k,csy1 is prepared by fusing ferrocyanide of potassium1 deprived of its water of crystallization1 intimately mixed with half its weight of sulphur and #ag parts of carbonate of potassa4 ,the molten mass1 after having cooled1 is exhausted with water1 the solution evaporated to dryness1 and extracted with alcohol1 from which the crystals of the salt are separated by evaporation4 ,it is also made by melting the ferrocyanide of potassium with sulphide of potassium4 ,it is a white1 crystallizable salt of a taste resembling that of niter1 soluble in water and alcohol1 and extremely poisonous4 ,it dissolves the chlorides1 iodides1 and bromides of silver1 is1 therefore1 a fixing agent1 but has not come in general use as such4 ,vogel speaks highly of it as an addition to the positive toning bath1 although he prefers the analogous ammonium salt in the following formula3 ,chloride of gold solution4444 7#a3ej7 #c c4 cm4 7#df-a_/e grains74 ,sulphocyanide of ammonium 444 #bj grammes 7#cjh grains74 ,water44444444#ajj c4 cm4 7#c ounces #e drachms #dj grains74 ,ferrocyanide of ,potassium--,k#b;,cfy#c;,,ho1 or ,k#b;,c#h,n#c;,fe#c;,,ho1 is generally known by the name of yellow prussiate of potassa4 ,it contains ferrocyanogen1 a compound radical1 consisting of #a eq4 of metallic iron and #c eq4 of the elements of cyanogen1 and is designated by the symbol ,cfy4 ,the potassium salt is manufactured on a large scale from refuse animal matter1 as old leather1 chips of horn1 woolen rags1 hoofs1 blood 7hence its ,german name1 ,blutlaugen salz71 greaves1 and other substances rich in nitrogen1 by fusing them with crude carbonate of potassa and iron scraps or filings to a red heat1 the operation to go on in an iron pot or shell1 with the exclusion of all air4 ,cyanide of potassium is generated in large quantities4 ,the melted mass is afterward treated with hot water1 which dissolves the cyanide and other salts1 the cyanide being then quickly converted by the action of oxide of iron1 formed during the operation of fusing1 into ferrocyanide4 ,the filtered solution is evaporated1 crystallized1 and recrystallized4 ,the best temperature for making the solution is between #aeh and #agf deg4 ,f4 ,the conversion of the cyanide into the ferrocyanide is greatly facilitated by the presence of finely divided sulphuret of iron and caustic potash4 ,some years ago this salt was manufactured by a process which dispensed with the use of animal matter1 the necessary nitrogen being obtained by a current of atmospheric air4 ,fragments of charcoal1 impregnated with carbonate of potassa1 were exposed to a white heat in a clay cylinder1 through which a current of air was drawn by a suction pump4 ,the process succeeded in a chemical sense1 but failed on the score of economy4 ,richard ,brunquell passes ammonia through tubes filled with charcoal1 and heated to redness so as to form cyanide of ammonium1 which is converted into the ferrocyanide of potassium by contact with potash solution and suitable iron compounds4 ,ferrocyanide of potassium is in large beautiful transparent four-sided tabular crystals1 of a lemon-yellow color1 soluble in four parts of cold and two of boiling water1 insoluble in alcohol4 ,exposed to heat it loses three eq4 of water1 and becomes anhydrous2 at a high temperature it yields cyanide of potassium1 carbide of iron1 and various gases4 ,this salt is said to have no poisonous properties1 although the dangerous hydrocyanic acid is made from it4 ,in large doses it occasions1 however1 vertigo1 numbness1 and coldness4 ,it is used in various photographic processes4 ,newton employs it in combination with pyrogallol and soda in the development of bromo-gelatine plates4 ,the ferri or ferrid cyanide of potassium discovered by ,gmelin is often1 but improperly1 termed red prussiate of potash4 ,it is formed by passing a current of chlorine gas through a solution of ferrocyanide of potassium until the liquid ceases to give a precipitate with a salt of sesquioxide of iron1 and acquires a deep1 reddish-green color4 ,the solution is then evaporated1 crystallized1 and recrystallized4 ,it forms regular prismatic or tabular crystals1 of a beautiful ruby-red tint1 permanent in the air1 soluble in four parts of cold water4 ,the crystals burn when introduced into the flame of a candle1 and emit sparks4 ,the theory of the formation of this salt is1 that one eq4 of chlorine withdraws from two eq4 of the ferrocyanide of potassium1 one eq4 of potassium1 forming chloride of potassium1 which remains in the mother liquid4 ,the reaction is explained by the following equation3 #b7,k#b;,cfy7,cl,k#c;,cfy#b,k,cl4 ,the radical ferridcyanogen1 isomeric#b with ferrocyanogen1 is supposed to be formed by the coalescence of two equivalents of ferrocyanogen1 and is represented by the symbol ,cfdy2 accordingly the formula of ferridcyanide of potassium is ,k#c;,cfdy4 ,footnote #b3 ,isomeric bodies1 or substances different in properties yet identical in composition1 are of constant occurrence in organic chemistry1 and stand among its most peculiar features4 ,ferridcyanide of potassium has found extensive application in photographic processes for intensifying negatives2 those of ,eder1 in combination with nitrate of lead1 or ,selle's1 with nitrate of uranium2 ,ander's blue intensification of gelatine negatives1 ,farmer's process of reducing intensity1 the coloring of diapositives1 the very important blue printing1 and various others1 are daily practiced in our laboratories4 ,the ferrocyanide of potassium is a chemical reagent of great value1 giving rise to precipitates with the neutral or slightly acid solutions of metals1 like the beautiful brown ferrocyanide of copper1 and that of lead4 ,when a ferrocyanide is added to a solution of a sesquioxide of iron1 ,prussian blue or ferrocyanide of iron is produced4 ,the exact composition of this remarkable substance is not distinctly stated1 as various blue compounds may be precipitated under different circumstances4 ,berzelius gives the following account3 #c eq4 of ferrocyanide and #b eq4 of sesquioxide of iron are mutually decomposed1 forming #a eq4 of ,prussian blue and #f eq4 of the potassa salt1 which remains in solution1 or #c,k#b;,cfy #b7;,fe#b,o#cc,,no#c7 ,fe#d;,cfy#c #f7,,ko1,,no#e74 ,it forms a bulky precipitate of an intense blue1 is quite insoluble in water or weak acids1 with the exception of oxalic acid1 with which it gives a deep blue liquid1 occasionally used as blue ink4 ,ferridcyanide of potassium1 added to a salt of the sesquioxide of iron1 yields no precipitate1 but merely darkens the reddish-brown solution2 with protoxide of iron it gives a blue precipitate1 containing ,fe#c;,cfdy1 which is of a brighter tint than that of ,prussian blue1 and is known by the name of ,turnbull's blue4 ,hence1 the ferridcyanide of potassium is as excellent a test for protoxide of iron as the yellow ferrocyanide is for the sesquioxide4--,e41 ,photo4 ,times4 99 99 99 99 99 ,,foucault',s ,,apparatus ,,for ,,manufacturing ,,illuminating ,,gas ,,and ,,hydrogen4 ,the illuminating gas and hydrogen apparatus1 illustrated herewith1 is adapted to all cases in which it is desirable to manufacture gas upon a small scale4 ,through the use solely of oil or water1 it produces illuminating gas or pure hydrogen for all the applications that may be required of them4 ,it consists of three parts1 viz41 of a vaporizer1 ,a1 which converts the liquids into gas2 of a distributer1 ,b1 which contains and distributes the liquids to be converted into gas1 and of a regulator1 ,c1 which automatically regulates the flow of the liquids in proportion as they are used4 ,illustration3 ,,fig4 #a4--;,,foucault',s ,,gas ,,apparatus4 ,in the vaporizer ,mr4 ,foucault1 the inventor of the apparatus1 obtains a perfectly regular combustion through the use of a central column1 #ae1 charged with fuel1 closed at the upper part1 open beneath1 and entering a furnace that is fed by it with regularity1 the zone of combustion not being able to extend beyond the level of the draught4 ,the grate1 #af1 is capable of revolving upon its axis in order to separate the cinders4 ,it also oscillates1 and is provided with jaws for crushing the fuel2 and it may likewise be lowered so as to let the fire drop into the ash-pan when it is desired to stop operations4 ,the vaporizer1 properly so called1 is not placed directly over the fire1 and for this reason the production of a spheroidal state of the liquid is avoided4 ,it consists of a vessel1 #dd1 into which the liquid is led by a pipe1 #dc4 ,the cast-iron evaporating vessel1 #ad1 is provided with appendages1 #ad bis1 which dip into the liquid and bring about its evaporation4 ,a refractory clay sleeve1 #da1 protects the lower part of the cylinder1 #ae1 from the fire1 and diminishes the smoke passages at #db4 ,the vapor produced makes its way vertically through a layer of charcoal placed between the evaporating vessel1 #ad1 and the receiver1 #ag1 and serving to decompose the aqueous vapor formed4 ,all clay and red and white lead joints are done away with in this part of the apparatus1 as are also packing bolts4 ,thus1 at the upper part the cover1 #ai1 is provided with a rim that enters a cavity filled with lead1 so1 too1 the lower part of the evaporating vessel1 #ad1 rests in a channel containing lead4 ,there is also at #cj1 a joint of the same character for the rim of the external cylindrical vessel1 #ah4 ,both this latter and the receiver1 #ag1 dip beneath into a tank of water1 #ff4 ,the distributer1 ,b1 is so arranged as to cause the water1 and oil1 and the liquids to be vaporized to flow with the greatest regularity1 and proportionally to the consumption of the gas in cases where the latter is not stored up in a gas meter4 ,the flow is controlled by cocks that are actuated by variations in the height of the regulator receiver4 ,all the condensation that occurs in the various parts of the apparatus collects in a receptacle1 #eb1 so arranged as to perform the office of a separator and set apart the oil at #bj1 and the water at #ba1 through the natural effect of their difference in density4 ,this latter is likewise utilized for causing the oil to flow into the vaporizer through #bf and #bg1 instead of using a graduated cock that receives a variable pressure from the receiver4 ,in this way every cause of obstruction is avoided4 ,illustration3 ,,fig4 #b4--,,section4 ,we have stated that the regulator1 ,c1 serves to automatically regulate the flow of the liquids proportionally to the consumption of the gases produced4 ,to effect this a communication is established between the regulator receiver1 #ei1 and the aperture through which the liquids flow1 and the flow is thus modified by the valves1 #ed and #ee4 ,the water contained in the reservoir of the regulator serves to wash the gas which enters through a number of orifices in the disk1 #fj1 this latter being fixed beneath the level of the water4 ,the gas may be purified by dissolving metallic salts in the water4 ,by means of the arrangement above described1 there may be manufactured at will a rich gas from liquid hydrocarburets1 hydrogen from water1 and gas obtained by an admixture of two others simultaneously produced and combined in the apparatus4--,chronique ,industrielle4 99 99 99 99 99 ,,sugar ,,nitro-,,glycerine4 ,a new explosive has been discovered by ,m4 ,roca1 a ,french engineer1 who communicates an account of it to ,le ,gnie ,civil4 ,the discovery was due entirely to scientific induction from some experiments made upon different specimens of dynamite1 with a view to the determination of the effect on the explosive force of the various inert or at least slowly combustible substances with which nitro-glycerine is mixed to produce the dynamite of commerce4 ,of late1 in place of the infusorial earth which formed the solid portion of ,nobel's dynamite1 such substances as sawdust1 powdered bark1 and even gunpowder1 have been used1 probably for the sake of economy alone1 without1 except in the latter case1 any reference to the influence which they might have upon the combustion of the nitro-glycerine2 but ,m4 ,roca1 in testing a variety of samples1 was struck by the difference among them in regard to energy of explosion1 and discovered that if a portion of free carbon1 sufficient to combine with the oxygen disengaged from the nitro-glycerine1 was present at the moment of detonation1 the effect was greater than where1 as in the case of gunpowder1 the solid portion alone furnished oxygen enough to burn all the free carbon1 without calling upon the nitro-glycerine for any4 ,in fact1 it appeared from experiment that the dose of carbon might with advantage be so great as not only to be itself oxidized into carbonic oxide by the oxygen of the nitro-glycerine1 but to reduce the carbonic acid developed by the explosion of the latter itself into carbonic oxide4 ,the limit of the advantageous effect of free carbon ceased here1 and if more were added to the mixture1 the cavities formed by the explosion in the lead cubes used for test were found simply lined with soot2 but up to the limit necessary for converting all the carbon in the dynamite into carbonic oxide1 the addition of a reducing agent was shown to be an important gain4 ,this was confirmed by theory1 which shows that pure nitro-glycerine1 which is composed of six parts of carbon and two of hydrogen1 combined with three times as much nitric acid and water1 decomposes on explosion into six parts of carbonic acid1 five of watery vapor1 one of oxygen1 and three of nitrogen1 while the addition of seven more parts of free carbon to the mixture causes the development1 by explosion1 of thirteen volumes of carbonic oxide1 five parts of watery vapor1 and three of nitrogen1 or twenty-one volumes of gas in place of fifteen4 ,as the power of an explosive depends principally on the amount of gas which results from its sudden combustion1 it was evident that the addition of pure or nearly pure carbon1 in a condition to be readily combined with the other elements1 ought to increase materially the force of nitro-glycerine1 and ,m4 ,roca experimented accordingly with an admixture of sugar1 as a highly carbonized body immediately available1 and found that three parts of this1 mixed with seven parts of nitro-glycerine1 detonated with a force from thirty to thirty-five per cent4 greater than that of pure nitro-glycerine4 ,many other organic carbonaceous substances may be employed in place of sugar1 with various advantages4 ,in comparing these simple compounds with the celebrated explosive gum1 prepared by dissolving gun-cotton in nitro-glycerine1 it is found that the latter is far inferior1 having an energy very little superior to that of pure nitro-glycerine4 99 99 99 99 99 ,,the ,,circle-,,divider4 ,this little apparatus1 invented by ,prof4 ,mora1 of ,senlis1 permits of dividing circumferences or circles into equal or proportional parts4 ,it consists 7,fig4 #b7 of a rule1 ,a1 divided into equal or proportional parts1 which pivots in the manner of a compass around a rod1 ,t1 that serves as a central rotary point4 ,along this rule moves a slide1 ,r1 provided with an aperture1 ,c1 which is made to coincide with one of the divisions4 ,this division corresponds to the number of equal or proportional parts into which the circle is to be divided4 ,the slide is provided with a wheel1 ,e1 that carries a point which serves at every revolution to trace the points that indicate the divisions of the circumference4 ,illustration3 ,,fig4 #a4--,,mode ,,of ,,using ,,the ,,circle ,,divider4 ,the apparatus operates as follows3 ,suppose1 for example1 that it becomes necessary to divide a circumference into #ai equal parts3 ,we make the aperture1 ,c1 coincide with the #aith division of the rule1 and fix the point of the rod1 ,t1 in the center of the circumference1 and cause the rule to revolve around it4 ,the wheel1 ,e1 will revolve upon its axis1 g1 and1 at every revolution1 its point will make a mark which corresponds to the #aith part of the circumference-- ,circumf4 c _/ ,circumf4 ,c r _/ ,r ,it is always necessary that the extremity of the wheel1 ,e1 and the center-point1 ,t1 shall be at the same height in order to have the divisions very accurate4 ,illustration3 ,,fig4 #b4--,,the ,,circle ,,divider4 99 99 99 99 99 ,,soluble ,,glass4 ,although the manufacture of soluble glass does not strictly belong to the glass maker's art1 yet it is an allied process to that of manufacturing glass4 ,of late soluble glass has been used with good effect as a preservative coating for stones1 a fire-proofing solution for wood and textile fabrics4 ,very thin gauze dipped in a solution of silicate of potash diluted with water1 and dried1 burns without flame1 blackens1 and carbonizes as if it were heated in a retort without contact of air4 ,as a fire-proofing material it would be excellent were it not that the alkaline reaction of this glass very often changes the coloring matters of paintings and textile fabrics4 ,since soluble glass always remains somewhat deliquescent1 even though the fabrics may have been thoroughly dried1 the moisture of the atmosphere is attracted1 and the goods remain damp4 ,this is the reason why its use has been abandoned for preserving theater decorations and wearing apparel4 ,another application of soluble glass has been made by surgeons for forming a protecting coat of silicate around broken limbs as a substitute for plaster1 starch1 or dextrine4 ,the only use where soluble glass has met with success is in the preservation of porous stones1 building materials1 paintings in distemper1 and painting on glass4 ,before we describe these applications1 we will give the processes used in making soluble glass4 ,the following ingredients are heated in a reverberatory furnace until fusion becomes quieted3 #a1bfj pounds white sand1 #ffj pounds potash of #gh4 ,this will produce #a1fij pounds of transparent1 homogeneous glass1 with a slight tinge of amber4 ,this glass is but little soluble in hot water4 ,to dissolve it1 the broken fragments are introduced into a iron digester charged with a sufficient quantity of water1 at a high pressure1 to make a solution marking #cc to #ce ,baume4 ,distilled or rain water should be used1 as the calcareous salts contained in ordinary water would produce insoluble salts of lime1 which would render the solution turbid and opalescent2 this solution contains silica and potash combined together in the proportion of #gj to #cj4 ,silicate of soda is made with #ahj parts of sand1 #ajj parts carbonate of soda 7#j4ia71 and is to be melted in the same manner as indicated previously4 ,soluble glass may also be prepared by the following method3 ,a mixture of sand with a solution of caustic potash or soda is introduced into an iron boiler1 under #e or #f atmospheres of pressure1 and heated for a few hours4 ,the iron boiler contains an agitator1 which is occasionally operated during the melting4 ,the liquid is allowed to cool until it reaches #bab1 and is drawn out after it has been allowed to clear by settling2 it is then concentrated until it reaches a density of #a4be1 or it may be evaporated to dryness in an iron kettle4 ,the metal is not affected by alkaline liquors4 ,the glass is soluble in boiling water2 cold water dissolves but little of it4 ,the solution is decomposed by all acids1 even by carbonic acid4 ,soluble glass is apparently coagulated by the addition of an alkaline salt2 mixed with powdered matters upon which alkalies have no effect1 it becomes sticky and agglutinative1 a sort of mineral glue4 ,to apply soluble glass for the preservation of buildings and monuments of porous materials1 take a solution of silicate of potash of #ce ,baume1 dilute it with twice its weight of water1 paint with a brush1 or inject with a pump2 give several coats4 ,experience has shown that three coats applied on three successive days are sufficient to preserve the materials indefinitely1 at a cost of about #ae cents per square yard4 ,when applied upon old materials1 it is necessary to wash them thoroughly with water4 ,the degree of concentration of the solutions to be used varies with the materials4 ,for hard stones1 such as sand and free stones1 rock1 etc41 the solution should mark #g to #i ,baume2 for soft stones with coarse grit1 #e to #g2 for calcareous stones of soft texture1 #f to #g4 ,the last coating should always be applied with a more dilute solution of #c to #d only4 ,authorities are divided upon the successful results of the preservation of stone by silicates4 ,some claim in the affirmative that the protection is permanent1 while others assert that with time and the humidity of the atmosphere the beneficial effects gradually disappear4 ,it might be worth while to experiment upon some of the porous sandstones1 which1 under the extreme influence of our climate1 rapidly deteriorate2 such1 for instance1 as the ,connecticut sandstone1 so popular at one time as a building material1 but which is now generally discarded1 owing to its tendency to crumble to pieces when exposed to the weather even for a few years4 ,soluble glass has also been used in ,germany to a great extent for mural painting1 known as stereochromy4 ,the process consists in first laying a ground with a lime water2 when this is thoroughly dry1 it is soaked with a solution of silicate of soda4 ,when this has completely solidified1 the upper coating is applied to the thickness of about one-sixteenth of an inch1 and should be put on very evenly4 ,it is then rubbed with fine sandstone to roughen the surface4 ,when thoroughly dry1 the colors are applied with water2 the wall is also frequently sprinkled with water4 ,the colors are now set by using a mixture of silicate of potash completely saturated with silica1 with a basic silicate of soda 7a flint liquor with soda base1 obtained by melting #b parts sand with #c parts of carbonate of soda74 ,as the colors applied do not stand the action of the brush1 the soluble glass is projected against the wall by means of a spray4 ,after a few days the walls should be washed with alcohol to remove the dust and alkali liberated4 ,the colors used for this style of painting are zinc white1 green oxide of chrome1 cobalt green1 chromate of lead1 colcothar1 ochers1 and ultramarine4 ,soluble glass has also been used in the manufacture of soaps made with palm and cocoanut oil2 this body renders them more alkaline and harder4 ,interesting experiments have been made with soluble glass for coloring corals and shells4 ,by plunging silicated shells into hot solutions of salts of chrome1 nickel1 cobalt1 or copper1 beautiful dyes in yellow1 green1 and blue are produced4 ,here seems to be a field for further application of this discovery4 ,soluble glass has also been applied to painting on glass in imitation of glass staining4 ,by using sulphate of baryta1 ultramarine1 oxide of chrome1 etc41 mixed with silicate of potash1 fast colors are obtained similar to the semi-transparent colors of painted windows4 ,by this means a variety of cheap painted glass may be made4 ,should these colors be fired in a furnace1 enameled surfaces would be produced4 ,as a substitute for albumen for fixing colors in calico printing1 soluble glass has been used with a certain degree of success2 also as a sizing for thread previous to weaving textile fabrics4 ,thus it would seem that this substance has been used for many purposes1 but since its application does not seem to have been extended to any great degree1 the defects here pointed out in its use as a fire-proofing material perhaps also exist1 to a certain degree1 in its other applications4 ,in painting upon glass1 for instance1 it is asserted that the brilliancy and finish of ordinary vitrified colors cannot be obtained4--,glassware ,reporter4 99 99 99 99 99 ,,the ,,jet ,,ventilator4 ,illustration3 ,,korting',s ,,jet ,,ventilator4 ,messrs4 ,korting bros41 of ,london1 induced by the interest that has been directed to the separate ventilation of mines in which fire-damp is apt to form1 have adopted for this purpose their jet ventilator4 ,the instrument1 which we illustrate in ,fig4 #a1 has been1 we understand1 considerable simplified1 and adapted for the special object in view4 ,the ventilators are worked by compressed air1 and are so arranged that1 without stopping their action1 the quantity of air they deliver can be rapidly increased or diminished4 ,this ample power of control has been arranged for by the special wish of the mining authorities1 who wish to regulate the ventilation according to the development of fire-damp or the greater or less number of men at work4 ,under circumstances of this kind the quantity of air taken into the mine can be changed instantly4 ,the illustrations1 ,figs4 #b1 #c1 and #d1 show different modes of fixing the jet ventilator4 ,in ,fig4 #b1 it is arranged to blow the air forward2 in ,fig4 #c1 it is shown exhausting the air2 and in ,fig4 #d1 it is represented as exhausting and blowing simultaneously1 the efficiency in each case being always the same4 ,any bends in the conduit affect the result to a very slight degree1 and the ventilator may be used with advantage when the conduit is divided as in ,fig4 #d1 in order to get the fresh air to different points4 ,the ventilators are easily fixed to the air conduits4 ,if they are to be connected to zinc air pipes1 the pipe is simply slipped over the point1 ,l4 in ,fig4 #a1 and if to wooden conduits the apparatus is simply put into them1 and if no other support is required4 ,furthermore1 they are so light that it suffices for one man to fix them or change their position4 ,messrs4 ,korting ,bros4 advance the following claims for this mode of ventilating mines3 ,certainty of action1 no moving parts whatever1 and1 consequently1 no need of lubrication2 no need of attention4 --,mech4 ,world4 99 99 99 99 99 ,,on ,,remelting ,,of ,,cast ,,iron4 ,from trials conducted by ,ledebur1 it appears that cast iron is rendered suitable for foundry purposes--i4e41 to fill the moulds well and to yield sharp and definite forms free of flaws1 to be cut with a chisel1 and turned on a lathe--through a certain percentage of graphite1 whose presence depends on that of carbon and silicium4 ,cast iron free of silicium yields on cooling the entire amount of carbon in the amorphous state1 while presence of the former metal gives rise to the formation of graphite1 and1 consequently1 causes a partial separation of carbon4 ,iron suffers on casting loss of graphite1 assumes a finely-grained texture1 becomes hard and brittle1 and is changed from gray to white4 ,in view of the fact that samples of cast iron with equal percentage of silicium and carbon yield on casting a different product1 it has become necessary to institute experiments as to the cause of this behavior4 ,samples of cast iron were therefore repeatedly melted1 and thin sections of each melt examined2 these sections exhibited a gray color1 though less apparent than in the unmelted sample1 and possessed sufficient softness to admit boring and filing4 ,during these processes of fusing1 the amount of silicium1 carbon1 and manganese had been gradually decreased1 and amounted to #ab4g1 #ag4f1 and #bd4d per centum for silicium in the three samples examined4 ,it also was observed that the more manganese the iron contains the less readily the percentage of silicium is diminished2 and since manganese is more subject to oxidation than silicium1 it is capable to reduce silicic acid of the slag or lining to metal1 and thus to augment the amount of silicium in cast iron4 ,the percentage of carbon also suffers diminution by oxidation1 which latter process is impeded by presence of manganese1 a fact of some importance in melting of cast iron in the cupola furnace4 ,an excess of manganese renders cast iron hard and brittle1 and imparts to it the properties to absorb gases1 while an amount of #a4e per centum1 as found in ,scotch iron1 undoubtedly has the effect to produce those properties for which this iron is held in high repute4 ,the amount of copper is not visibly altered by fusion1 but that of phosphorus and sulphur slowly increased4 ,experiments in regard to the relation between chemical composition and strength of the material have established that a large amount of silicium1 graphite1 manganese1 and combined carbon reduce the elasticity1 strength1 and tenacity of cast iron1 and that a limited percentage of silicium counteracts the injurious influence produced by an excess of combined carbon4 ,on remelting of cast iron1 increase in tensile strength was observed1 which attained its maximum in iron with a small percentage of silicium after the third1 and in such with a large amount after the fourth melting4 ,the increase in tensile strength was accompanied by a loss of silicium1 graphite1 and manganese coupled with a simultaneous augmentation of combined carbon4 ,a fifth melting of the cast iron renders it hard1 brittle1 and white1 through oxidation of silicium and subsequent lowering of the amount of carbon4 ,on lessening the percentage of combined carbon with formation of graphite the injurious influence of the accessorial constituents of cast iron is diminished1 especially that produced by the presence of phosphorus4--,eisenhuettentechnik4 99 99 99 99 99 ,,feeding ,,boilers ,,at ,,the ,,bottom4 ,one of the most important things to be considered in boiler construction is the position and arrangement of the feed apparatus1 but it is1 unfortunately1 one of the elements that is most often overlooked1 or1 if considered at all1 only in a very superficial manner4 ,many seem to think that it is only necessary to have a hole somewhere in the boiler--no matter what part--through which water may be pumped1 and we have all that is desired4 ,this is a very grave error4 ,many boilers have been ruined1 and 7we make the assertion with the confidence born of long experience7 a large number of destructive explosions have been directly caused by introducing the feed water into boilers at the wrong point4 ,on the location and construction of the feed depends to some extent the economical working of a boiler1 and1 to a great extent1 especially with certain types of boilers1 its safety1 durability1 and freedom from a variety of defects1 such as leaky seams1 fractured plates1 and others of a similar kind4 ,and it is unfortunately true that the type of boiler which from its nature is most severely affected by mal-construction1 such as we are now speaking of1 is the very one which is the oftenest subject to it4 ,we are speaking now more particularly of the plain cylinder boiler1 of which there are many in use throughout the country4 ,plain cylinder boilers are1 as a rule1 provided with mud drums located near the back end4 ,as a rule1 also1 these boilers are set in pairs over a single furnace1 and the mud drum extends across beneath1 and is connected to both1 and one end projects through the setting wall at the side4 ,our illustrations show a typical arrangement of this kind4 ,fig4 #a shows a transverse section of the boilers and setting1 while ,fig4 #b shows a longitudinal section of the same4 ,it is a favorite method to connect the feed pipe1 ,f1 to the end of the mud drum which projects through the wall1 and here the feed water is introduced1 whether hot or cold2 and there is really not so much difference after all between the two1 for no matter how effective a heater may be1 the temperature to which it can raise water passing through is quite low compared with the temperature of the water in the boiler due to a steam pressure of say eighty pounds per square inch4 ,the difference in the effect produced by feeding hot or cold water at the wrong place is one of degree1 not of kind4 ,when a boiler is under steam of say eighty pounds per square inch1 the body of water in it will have a temperature of about #cbd degrees ,fahr41 and the shell plates will necessarily be somewhat hotter1 especially on the bottom 7just how much hotter will depend entirely upon the quantity of scale or sediment present74 ,now introduce a large volume of cold water through an opening in the bottom1 and what becomes of it8 ,does it rise at once1 and become mixed with the large body of water in the boiler8 ,by no means4 ,it cannot rise until it has become heated1 for there is a great difference between the specific gravity of water at #fj1 or even #bab ,fahr41 and water at #cbd4 ,consequently1 it hugs the bottom of the boiler1 and flows toward the front end1 or hottest portion of the shell4 ,now let us examine the effect which it produces4 ,we know that wrought iron expands or contracts about #a part in #aej1jjj for each degree that its temperature is raised or lowered4 ,this is equivalent to a stress of one ton per square inch of section for every #ae degrees4 ,that is1 suppose we fix a piece of iron1 a strip of boilerplate1 for instance1 of an inch thick and #d inches wide1 at a temperature of #ib degrees ,fahr41 between a pair of immovable clamps4 ,then1 if we reduce the temperature of the bar under experiment to that of melting ice1 we put a stress of four tons upon it1 or one ton for each inch of its width4 ,illustration3 ,,fig4 #a ,now this is precisely what happens when cold water is fed into the bottom of a boiler4 ,we have the plates of the shell at a temperature of not less1 probably1 than #cej ,fahr4 ,a large quantity of cold water1 often at a temperature as low as #ej ,fahr41 is introduced through an opening in the bottom1 and flows along over these heated plates4 ,if it could produce its full effect at once1 the contraction caused thereby would bring a stress of #cjj #ae #bj tons per square inch upon the bottom plates of the shell4 ,but fortunately it cannot exert its full effect at once1 but it can act to such an extent that we have known it to rupture the plates of a new boiler through the seams on the bottom no less than three times in less than six weeks after the boilers were started up4 ,the effect in such cases will always be the most marked1 especially if the plant is furnished with a heater1 when the engine is not running1 for then1 as no steam is being drawn from the boilers1 there is comparatively little circulation going on in the water in the boiler1 and the water pumped in1 colder than usual from the fact that the heater is not in operation1 spreads out in a thin layer on the lowest point of the shell1 and stays there1 and keeps the temperature of the shell down1 owing to the fires being banked or the draught shut1 while the larger body of water above1 at a temperature of from #cjj to #cbe degrees1 keeps the upper portion of the shell at its higher temperature4 ,it will readily be seen that the strain brought upon the seams along the bottom is something enormous1 and we can understand why it is that many boilers of this class rupture their girth seams while being filled up for the night after the engine has been shut down4 ,to most persons who have but a slight knowledge of the matter1 we fancy it would be a surprise to see the persistence with which cold water will hug the bottom of a boiler under such circumstances4 ,we have seen boilers when the fire has been drawn1 and cold water pumped in to cool them off1 so cold on the bottom that they felt cold to the touch1 and must consequently have had a temperature considerably below #ajj ,fahr41 while the water on top1 above the tubes1 was sufficiently hot to scald2 and they will remain in such a condition for hours4 ,illustration3 ,,fig4 #b4 ,the only thing to be done1 where feed connections are made in the manner described1 is to change them1 and by changing them at once much trouble1 or even a disastrous explosion1 may be avoided4 ,put the feedpipe in through the front head1 at the point marked p in ,fig4 #a1 drill and tap a hole the proper size for the feed pipe1 cut a long thread on the end of the pipe1 and screw the pipe through the head1 letting it project through on the inside far enough to put on a coupling1 then screw into the coupling a piece of pipe not less than eight or ten feet long1 letting it run horizontally toward the back end of the boiler1 the whole arrangement being only from #c to #d inches below the water line of the boiler1 and hot or cold water may be fed indifferently1 without fear of danger from ruptured plates or leaky seams4 ,in short1 put in a top feed1 and avoid further trouble4--,the ,locomotive4 99 99 99 99 99 ,,microscopical ,,journal4 ,,iron ,,printing ,,and ,,microscopic ,,photography4 ,by ,c4,m4 ,,vorce1 ,f4,r4,m4,s4 ,i4 ,,formulas ,,for ,,printing ,,solutions4 ,blue ,prints4--,the best formula for this process1 of many that ,i have tried1 is that furnished by ,prof4 ,c4,h4 ,kain1 of ,camden1 ,n4,j41 in which the quantity of ammonio-citrate of iron is exactly double that of the red prussiate of potash1 and the solutions strong4 ,this gives strong prints of a bright dark blue1 and prints very quickly in clear sunlight4 ,dissolve six grains of red prussiate of potash in one drm4 of distilled water2 in another drm4 of distilled water dissolve twelve grains of ammonio-citrate of iron4 ,mix the two solutions in a cup or saucer1 and at once brush over the surface of clean strong paper4 ,cover the surface thoroughly1 but apply no more than the paper will take up at once2 it should become limp and moist1 but not wet4 ,the above quantity of solution1 two drms41 will suffice to sensitize ten square feet of paper1 or three sheets of the regular size of plain paper1 #ahbb4 ,as fast as the sheets are washed over with the solution1 hang them up to dry by one corner4 ,the surplus fluid will collect in a drop at the lower corner1 and can be blotted off4 ,black ,prints4--,wash the paper with a saturated solution of bichromate of potash1 made quite acid with acetic acid4 ,after printing1 wash the prints in running water for twenty to thirty minutes1 then float them face down on a weak solution 7five to ten per cent47 of protosulphate of iron for five minutes1 and wash as before4 ,if preferred1 the iron solution may be washed over the prints1 or they may be immersed in it1 but floating seems preferable4 ,after the second washing1 wash the prints over with a strong solution of pyrogallic acid1 when the print will develop black1 and the ground1 if the washings were sufficient1 will remain white4 ,a final washing completes the process4 ,if a solution of yellow prussiate of potash be used in place of the pyro solution1 a blue print is obtained4 ,bichromate prints can be made on albumenized paper by floating it on the solution1 and by using a saturated solution of protosulphate of iron and a saturated solution of gallic acid4 ,very fine prints can be so produced nearly equal to silver prints1 and at somewhat less cost1 but with a little or no saving of time or labor4 ,chief ,proof ,solution4--,if old oxalate developer be exposed in a shallow vessel in a warm place1 a deposit of light green crystals will be formed1 composed of an impure oxalate of iron4 ,if these crystals be dissolved in water1 and paper washed with a strong solution1 when dry it may be exposed in the printing-frame1 giving full time4 ,the image is very faint1 but on washing in or floating on a moderately strong solution of red prussiate of potash for a minute or less1 a blue positive is produced1 which is washed in water as usual to fix it4 ,the unused developer produces the best crystals for the purpose1 and the pure ammonio-oxalate is vastly better than either4 ,all of the above operations1 except the printing1 should be carried on in the dark room1 or by lamp or gas light only4 ,the solutions and the paper should also be kept in the dark1 and prepared as short a time as possible before use4 ,,ii4 ,,compound ,,negatives4 ,in photographing with the microscope1 it frequently occurs that the operator1 instead of devoting a negative to each of two or more similar objects for comparison1 printing both upon the same print1 prefers to have the whole series upon one negative1 and taking from this a single print4 ,there is often room for two or more images upon the same plate4 ,if the center of the plate is devoted to one1 obviously no more can be accommodated on it1 but by placing one at each end1 or one on each quarter of the plate1 both economy of plates and convenience of printing are secured4 ,the end may be readily accomplished by matting the plate as a negative is matted in printing4 ,suppose it be desired to photograph four different species of acari on one plate1 the image of each when magnified to the desired extent only covering about one-fourth the exposed area of the plate4 ,first1 a mat is prepared of card-board or thick non-actinic paper1 which is adjusted to exactly fill the opening of the plate holder1 lying in front of and close against the plate when exposed1 and having one-quarter very exactly cut out4 ,a convenient way to fit this mat is to leave projecting lugs on each side at exactly the same distance from the ends1 and cut notches in the plate-holder into which the lugs may closely fit4 ,if this work is carefully done1 the mat may be reversed both sidewise and endwise1 and the lugs will fit the notches2 if so1 it is ready for use4 ,the object being focused upon the focusing glass or card1 the camera is raised one-half the vertical dimension of the plate and displaced to one side half the horizontal dimension1 when the image will be found to occupy one-quarter of the plate4 ,the mat being placed in the plate holder1 a focusing glass is inserted in the position the plate will occupy1 and final adjustment and focusing made4 ,the plate is then marked on one corner on the film side with a lead pencil1 placed in the holder without disturbing the mat1 and the exposure made4 ,when the plate is replaced for a second exposure1 either the mat is reversed or the plate turned end for end2 but it is best to always place the plate in the holder in the same position and change the mat to expose successive quarters1 but this requires the camera to be moved for each exposure4 ,with similar objects1 and some judgment in making two exposures1 negatives may be made with almost exactly the same density in each quarter1 and by cutting out slightly less than one-quarter of the mat the four images will be separated by black lines in the print2 by cutting out a trifle more than the exact quarter1 they will be separated by white lines instead of black4 99 99 99 99 99 ,,practical ,,directions ,,for ,,making ,,lantern ,,transparencies4 ,footnote3 ,abstract of a paper communicated to the ,glasgow and ,west of ,scotland ,amateur ,photographic ,association4--,from the ,photographic ,news4 ,by ,t4,n4 ,,armstrong4 ,when the season for out-door work closes1 amateurs begin to look about for means of employment during the dark evenings4 ,there is1 fortunately1 no necessity for being idle1 or to relinquish photographic pursuits entirely1 even though the weather and light combine to render out-door work almost impracticable2 and most amateurs will be found to have some hobby or favorite amusement which enables them to keep in practice during those months when many channels of employment are closed to them2 and probably one of the most popular as well as the most pleasing occupations is the production of transparencies for the lantern4 ,it is not my desire to enter into any discussion as to this or that being the best means of producing these delightful pictures1 but merely to describe a way by which a pleasant evening can be spent at photography1 and slides produced of much excellence by artificial light4 ,to-night ,i propose1 by the aid of artificial light1 to make a few slides with ,beechy's dry plates4 ,on the whole1 ,i have been most successful with them1 and have obtained results more satisfactory than by any of the other processes ,i have tried4 ,i do not say that results quite as good cannot be obtained by any other method1 for ,i know manipulative skill plays a most important part in this class of work4 ,when ,i first took up the making of transparencies with wet collodion1 ,i was told that my sorrows would not be far to seek1 and so ,i soon found out4 ,need ,i tell you of all my failures1 such as films floating off the glass1 oyster-shell markings1 pin-holes1 films splitting when dry1 etc41 etc41 not to speak of going to business with fingers in fearful state with nitrate of silver and iron developer8 ,now all these miseries have gone1 and ,i can1 with dry collodion plates1 work with the greatest of comfort1 and obtain results quite equal to the best products of any method4 ,it may be interesting to some to know the formula by which the emulsion is made1 and as the making of it is by no means a difficult operation1 ,i may be pardoned if1 before going fully into the more practical part of my paper1 ,i describe the formula1 and also the manner in which ,i coat and dry the plates4 ,the formula is as follows1 for which the world is indebted to ,canon ,beechy3 ,in #h ounces of absolute alcohol dissolve #e drachms of anhydrous bromide of cadmium4 ,the solution will be milky4 ,let it stand at least twenty-four hours1 or until perfectly clear2 it will deposit a white powder4 ,decant carefully into an #h-ounce bottle1 and add to it a drachm of strong hydrochloric acid4 ,label this bromide solution2 and it is well to add on the label the constituents1 which will be found to be nearly3 ,alcohol4 #a ounce4 ,bromide of cadmium4 #cb grains4 ,hydrochloric acid4 #h drops4 ,this solution will keep for ever1 and will be sufficient to last two or three years1 and with this at hand you will be able in two days to prepare a batch of plates at any time4 ,in doing so1 you should proceed thus3 ,make up your mind how many plates you mean to make1 and take of the above accordingly4 ,for two dozen -plates or four dozen #c by #c1 dissolve by heat over1 but not too near1 a spirit lamp1 and by yellow light1 #dj grains of nitrate of silver in #a ounce of alcohol #j4hbj4 ,while this is dissolving in a little ,florence flask on a retort stand at a safe distance from the lamp--which it will do in about #e minutes--take of the bromized solution an ounce1 of absolute ether #a ounce1 of gun-cotton grains2 put these in a clean bottle1 shake once or twice1 and the gun-cotton1 if good1 will entirely dissolve4 ,as soon as the silver is all dissolved1 and while quite hot1 pour out the above bromized collodion into a clean #d-ounce measure1 having ready in it a clean slip of glass4 ,pour into it the hot solution of silver in a continuous stream1 stirring rapidly all the while with a glass rod4 ,the result will be a perfectly smooth emulsion without lumps or deposit1 containing1 with sufficient exactitude for all practical purposes1 #h grains of bromide1 #af grains of nitrate of silver1 and #b drops of hydrochloric acid per ounce4 ,put this in your stock solution bottle1 and keep it in a dark place for twenty-four hours4 ,when first put in1 it will be milky2 when taken out1 it will be creamy2 and it will be well to shake it once or twice in the twenty-four hours4 ,at the end of this time you can make your two dozen plates in about an hour4 ,proceed as follows3 ,have two porcelain dishes large enough to hold four or six of your plates2 into one put sufficient clean water to nearly fill it1 into the other put #cj ounces of clear1 flat1 not acid1 bitter beer1 in which you have dissolved #cj grains of pyrogallic acid4 ,pour this through a filter into the dish1 and avoid bubbles4 ,if allowed to stand an hour1 any beer will be flat enough2 if the beer be at all brisk1 it will be difficult to avoid small bubbles on the plate4 ,at all events1 let your preservative stand while you filter your emulsion4 ,this must be done through perfectly clean cotton-wool into a perfectly clean collodion bottle2 give the emulsion a good shaking1 and when all bubbles have subsided1 pour it into the funnel1 and it will go through in five minutes4 ,the filtered emulsion will be found to be a soft1 smooth1 creamy fluid1 flowing easily and equally over the plates4 ,coat with it six plates in succession1 and place each1 as you coat it1 into the water4 ,by the time the sixth is in1 the first will be ready to come out4 ,take it out1 see that all greasiness is gone1 and place it in the preservative1 going on till all the plates are so treated4 ,a very handy way of drying is to have a flat tin box of the usual hot plate description1 which fill with hot water1 then screw on the cap2 on this flat tin box place the plates to dry1 which they will do rapidly2 when dry1 store away in your plate box1 and you will have a supply of really excellent dry collodion plates4 ,just a word as to the preparation of the glasses before coating4 ,it is very generally considered that it is better the glasses receive either a substratum of albumen or very weak gelatine4 ,i use the latter on account of the great ease of its preparation4 ,after your glasses are well cleaned1 place them in1 and rub them with a weak solution of hydrochloric acid of the strength of #b ounces acid to #ah ounces water4 ,prepare a solution of gelatine #a grain to the ounce of water1 rinse the plate after removal from the acid mixtures1 and coat twice with the above gelatine substratum2 the first coating is to remove the surplus water1 and should be rejected4 ,rear the plates up to drain1 and dry in a plate rack or against a wall1 and be careful to prevent any dust adhering to the surface while wet4 ,having now described the plates ,i intend to use1 let us next consider what a transparency is1 that we may understand the nature of the work we are undertaking4 ,you are all aware that if we take a negative1 and in contact with it place a sheet of sensitized paper1 we obtain a positive picture4 ,substitute for the paper a sensitive glass plate1 and we obtain also a positive picture1 but1 unlike the paper print1 the collodion or other plate will require to be developed to bring the image into view4 ,now this is what is termed making a transparency by contact4 ,it often happens1 however1 that a lantern slide #c by #c has to embrace the whole of a picture contained in a much larger negative1 so that recourse must be had to the camera1 and the picture reduced with the aid of a short focus lens to within the lantern size2 this is what is called making a transparency by reduction in the camera4 ,both cases are the same1 however1 so far as the process being simply one of printing4 ,those who have never made a transparency will have doubtless printed silver prints from their negatives1 and when printing1 how often do you find that to secure the best results you require to have recourse to some little dodge4 ,now1 let us bear this in mind when using such a negative for the printing of a transparency1 for1 as ,i have said before1 it is only a process of printing1 after all4 ,although we cannot1 when using a sensitive plate1 employ the same means of dodging as in the case of a silver print1 still we are not left without a means of obtaining the same results in a different way1 and this just brings me to what ,i have already hinted at previously1 that a deal more depends on the manipulative skill of the operator than in the adoption of any particular make plate or formula2 and not only does this manipulative skill show itself in the exposure1 development1 etc41 but likewise comes into play in a marked manner even in the preparation of the negative for transparency printing4 ,let me deal with the latter point first4 ,you will at once understand that a negative whose size bears a proportion similar to #c by #c will lend itself more easily to reduction2 thus whole plate or half plate negatives are easy of manipulation in this respect1 and require but little doing up4 ,but as other sizes have at times to be copied into a disk by #c1 recourse must be had to a sort of squaring of the negative4 ,now1 here ,i have a negative #g by #d1 which is perhaps the worst of all sizes to compress into the lantern shape1 so ,i have1 as it were1 to square this negative1 and this ,i do by simply adding to sky4 ,i take a piece of card-board and gum it on to the glass side of the negative1 and this addition gives me a size that lends itself easily to reduction to the lantern disk1 and in no way detracts from the picture4 ,having said so much about making up the size1 let me add a few words as to other preparations that are sometimes necessary4 ,in a good lantern transparency1 it is1 of all things1 indispensable that the high lights be represented by pure glass1 absolutely clean in the sense of its being free from any fog or deposit1 to even the slightest degree2 it is also necessary that it be free from everything of heaviness of smudginess in the details4 ,to obtain these results1 ,i generally have recourse to the strengthening of the high lights of my negatives1 and this ,i do with a camel's hair brush and ,india ink1 working on the glass side4 ,i nearly always block out my skies1 and so strengthen the other parts of my negatives1 that ,i can rely on a full exposure without fear of heaviness or smudginess4 ,this blocking out is easily done4 ,haying said so much about the preparation of the negative1 let me now describe the apparatus ,i use4 ,i have here an ordinary flat board1 and here my usual camera2 it is the one ,i use both for outside and inside work4 ,it is a whole-plate one1 very strongly made1 and has a draw of twenty-three inches when fully extended2 but this is not an unusual feature1 as nearly all modern cameras have their draw made as long as this one4 ,the lens ,i use is a ,ross rapid symmetrical on five inches focus1 and here ,i have a broken-down printing frame with the springs taken off1 and here a sheet of ground glass4 ,this is all that is required4 ,i mention this because ,i find it generally believed that a special camera is required for this work1 such as to exclude all light between the negative and the lens2 in my practice ,i have found this unnecessary4 ,there is nothing to hinder the use of ordinary cameras1 provided the draw is long enough1 and the lens a short focus one4 ,now let me describe how to go to work4 ,i take the negative and place it in the printing-frame1 holding it in its place with a couple of tacks1 film-side next the lens1 just as in printing2 then stand the printing frame on its edge on the flat board1 and place the ground glass in front of it--when ,i say in front of it1 ,i mean not between the negative and lens1 but between the light and the negative4 ,the ground glass can conveniently be placed in another printing frame1 and both placed up against each other4 ,i then bring my camera into play1 and so adjust the draw and distance from the negative1 till ,i get the picture within the disk on my ground glass4 ,i find the best way is to gum a transparency mask on the inside of the ground glass2 this permits of the picture being more easily brought within the required register4 ,this done1 focus sharply1 cap the lens1 and then proceed to make the exposure4 ,now1 what shall ,i say regarding exposure8 ,just let us bear in mind again that it is merely a printing process we are following up1 as you will all know that in printing no two negatives are alike in the time they require4 ,so in this case no two negatives are the same in their required exposure4 ,still1 with the plates ,i am going to use1 so wide is their range for exposure that but few failures will be made on this score1 provided we are on the safe side1 and expose fully4 ,although these plates are not nearly so fast as gelatine plates1 it may surprise you to be told that working with a negative which to daylight at this dull time of the year required an exposure of sixteen minutes1 will1 ,i hope1 give me good results in about a tenth of this time2 and this ,i obtain by burning magnesium ribbon4 ,at first the error ,i fell into when using magnesium ribbon was too much concentration of light4 ,i now never allow the ribbon1 when burning1 to remain in one position1 but keep it moving from side to side1 and up and down1 in front of the ground glass while making my exposure2 and if there be any dense place in the negative which1 as in printing1 would have required printing specially up1 ,i allow the light to act more strongly on that part2 the result1 as a rule1 being an evenly and well exposed plate4 ,i must not forget to explain to you the manner in which ,i coil up the ribbon before ,i set it alight4 ,i take an ordinary lead pencil1 and wind the ribbon round and round1 thus making a sort of spiral spring2 this done1 ,i gently pull the coils asunder4 ,i then grasp the end of the ribbon with a pair of pincers1 light the other end1 and make my exposure4 ,having said so much regarding exposure1 ,i shall now proceed to deal with development4 ,you will see me use a canary light1 with which ,i can easily see to read a newspaper4 ,it may cause some of you surprise to see me use so much light4 ,it is the same lamp that ,i use for developing all my rapid bromide plates2 it is the best lamp ,i ever used4 ,the canary medium is inserted between the two sheets of glass #g by #d1 the two glasses are then fastened on to the tin with gummed paper1 a few holes are bored in the back for air1 a funnel let in1 and the thing is complete4 ,the formula for development is as follows3 ,pyro4 #if grains4 ,methylated spirits4 #a ounce4 ,bromide of potash4 #ab grams4 ,water4 #a ounce4 ,carbonate ammonia4 #fj grains4 ,water4 #a ounce4 ,mix #cj drops pyro with from #cj to #fj drops bromide1 then add #b drachms ammonia solution and #b drachms of water4 ,i find a thin negative requires a slow development1 and so gain contrast2 while hard negatives are best over-exposed and quickly developed4 ,the plate is first placed in water or rinsed under a gentle stream from the tap till all greasiness has disappeared1 it is then placed in a flat dish1 and the developer applied4 ,should it be found that some parts of the picture are denser printed than should be by the ribbon acting more strongly on some particular part--this is often the case if the negative has been thinner in some parts than others1 through uneven coating of the plate--the picture need not be discarded as a failure1 for ,i will explain to you later on how to overcome this difficulty4 ,fix the plate in hypo--the fixing takes place very quickly--then examine the picture for the faults above described2 if they are found1 wash the plate under the tap gently1 and bring into operation a camel's hair brush and a weak solution of cyanide of potassium4 ,apply the brush to the over-printed parts1 taking care not to work on the places that are not too dense4 ,do not be afraid to use plenty of washing while this is being done2 let it be1 as it were1 a touch of the brush and then a dash of water1 and you will soon reduce the over-printed parts4 ,it only requires a little care in applying the brush4 ,after this wash well1 and should it be deemed necessary to tone to a black tone1 use a weak solution of bichloride of platinum and chloride of gold1 or a very weak solution of iridium1 in equal quantities1 allowing the picture to lie in the solution till the color has changed right through to the back of the glass4 ,should a warm pinkish tone be desired1 ,i tone with weak solutions of ferri cyanide of potassium1 nitrate of uranium1 and chloride of gold in about equal quantities4 ,after toning1 wash well and dry2 they dry quickly4 ,varnish with ,soehnee crystal varnish1 then mount with covering glasses1 and mark4 ,bind round the edges with paper and very stiff gum1 and the picture is complete4 ,the making of a really good transparency is by no means an easy or pleasant task with a wet collodion plate1 but with these dry plates an amateur can1 with a little practice1 produce comfortably slides quite equal to those procurable from professional makers4 99 99 99 99 99 ,,the ,,honigmann ,,fireless ,,engine4 ,the invention of a self propelling engine1 capable of working without fuel economically and for a considerable time1 has often been attempted1 and was1 perhaps1 never before so nearly accomplished as about the time of the introduction into practical use of ,faure's electric storage batteries2 but at the present moment it appears that electric power has to give way once more to steam power4 ,mr4 ,honigmann's invention of the fireless working of steam engines by means of a solution of hydrate of soda--,na,o ,,ho--in water is not quite two years old1 and has in that time progressed so steadily towards practical success that it is reasonable to expect its application before long in many cases of locomotion where the chimney is felt to be a nuisance4 ,the invention is based upon the discovery that solutions of caustic soda or potash and other solutions in water1 which have high boiling points1 liberate heat while absorbing steam1 which heat can be utilized for the production of fresh steam4 ,this is eminently the case with solutions of caustic soda1 which completely absorb steam until the boiling point is nearly reached1 which corresponds to the degree of dilution4 ,if1 therefore1 a steam boiler is surrounded by a vessel containing a solution of hydrate of soda1 having a high boiling point1 and if the steam1 after having done the work of propelling the pistons of an engine1 is conducted with a reduced pressure and a reduced temperature into the solution1 the latter1 absorbing the steam1 is diluted with simultaneous development of heat1 which produces fresh steam in the boiler4 ,this process will be made clearer by referring to the following table of the boiling points of soda solutions of different degrees of concentration1 and by the description of an experiment conducted by ,professor ,riedler with a double cylinder engine and tubular boiler as shown in ,fig4 #b3 ---------------------------------------- --------------------- ,boiling point in ,steam pressure above ,solution of soda4 ,centigrades4 atmospheric pressure in atmospheres4 ---------------------------------------- --------------------- #ajj ,na,o ,,ho #aj ,h#b,o #bef deg4 ,c4 #dj atm4 #bj #bbj4e #ba #cj #bjj #ae #dj #ahe4e #aj4b #ej #agd4e #g4g #fj #aff #f4a #gj #aei4e #e4a #hj #aed #d4b #ij #adi #c4f #ajj #add #c4j #abj #acf #b4b #adj #acj #a4f #bjj #abj #j4ie #cjj #aaj4c #j4d #djj #ajg #j4c ---------------------------------------- --------------------- ,experiment ,no4 #ae4c--,the boiler of the engine1 ,fig4 #b1 was filled with #bca kilogs4 water of two atmospheres pressure and a temperature of about #ace deg4 ,cent42 the soda vessel with #edd kilogs4 of soda lye of #bb4i per cent4 water and a temperature of #bjj deg4 ,cent41 its boiling point being about #bah deg4 ,cent4 ,the engine overcame the frictional resistance produced by a brake4 ,at starting the temperature of both liquids had become nearly equal1 viz41 about #aec deg4 ,cent4 ,the temperature of the soda lye could therefore be raised by #dg deg4 ,cent1 before boiling took place1 but1 as dilution1 consequent upon absorption of steam would take place1 a boiling point could only be reached less than #bah deg4 ,cent41 but more than #aec deg4 ,cent4 ,the engine was then set in motion at #ajj revolutions per minute4 ,the steam passing through the engine reached the soda vessel with a temperature of #ajj deg4 ,cent42 the temperature of the soda lye began to rise almost immediately1 but at the same time the steam boiler losing steam above1 and not being influenced as quickly by the increased heat below1 showed a decrease of temperature4 ,the difference of the two temperatures1 which was at starting #a4c deg4 ,cent41 consequently increased to #g4b deg4 ,cent1 after #ag min41 the boiler having then its lowest temperature of #adh4h deg4 ,cent4 ,after that both temperatures rose together1 the difference between them increasing slightly to #i4e deg4 ,cent41 and then decreasing continually4 ,after #b hours #ac min41 when the engine had made #ab1jjj revolutions1 the soda solution had reached a temperature of #agj4c deg4 ,cent41 which proved to be its boiling point4 ,the steam from the engine was now blown off into the open air during the next #bd min4 ,this lowered the temperature of both water and soda lye by #aj deg4 and re-established its absorbing capacity4 ,the steam produced under these circumstances had of course a smaller pressure than before1 in this way the engine could be driven at reduced steam pressures until the resistance became relatively too great4 ,the process described above is illustrated by the diagram ,fig4 #a1 which is drawn according to the observations during the experiment4 ,footnote #c3 ,zeitschrift d4 ,vereins ,deutscher ,ingenieur1 #ahhc1 p4 #gcj2 #ahhd1 p4 #fi4 ,illustration3 ,,fig4 #a4 ,illustration3 ,,fig4 #b4 ,the constant rise of both temperatures during the first two hours1 which is an undesirable feature of this experiment1 was caused by the quantity of soda lye being too great in proportion to that of water1 and other experiments have shown that it is also caused by an increased resistance of the engine1 and consequent greater consumption of steam4 ,in the latter part of the experiment1 where the engine worked with expansion1 the rise of the temperature was much less1 and by its judicious application1 together with a proper proportion between the quantities of the two liquids in the engines1 which are now in practical use1 the rising of the temperatures has been avoided4 ,the smaller the difference is between the temperatures of the soda lye and the water the more favorable is the economical working of the process4 ,it can be attained by an increase of the heating surface as well as by a sparing consumption of steam1 together with an ample quantity of soda lye1 especially if the steam is made dry by superheating4 ,in the diagrams ,figs4 #c and #d1 taken from a passenger engine which does regular service on the railway between ,wurselen and ,stolberg1 the difference of the two temperatures is generally less than4 #aj deg4 ,cent4 ,these diagrams contain the temperatures during the four journeys a b c d1 which are performed with only one quantity of soda lye during about twelve hours1 and show the effects of the changing resistances of the engine and of the duration of the process upon the steam pressure1 which1 considering the condition of the gradients1 are generally not greater than in an ordinary locomotive engine4 ,it can especially be seen from these diagrams that an increase of the resistance is immediately and automatically followed by an increased production of steam4 ,this is an important advantage of the soda engine over the coal-burning engine1 in consequence of which less skill is required for the regular production of steam power4 ,the tramway engines of more recent construction according to ,honigmann's system--,figs4 #e and #f--;are worked with a closed soda vessel in which a pressure of #a_/b to #a atmospheres is gradually developed during the process4 ,while the counter pressure thus produced offers only a slight disadvantage1 being at an average only #a_/b atmosphere1 the absorbing power of the soda lye is materially increased1 as shown by the following table1 and it is1 therefore1 possible to work with higher pressures than with an open soda vessel4 ,besides this great advantage1 it is also of importance that the pressure in the steam boiler can be kept at a more uniform height4 ,illustration3 ,,fig4 #c4 ,illustration3 ,,fig4 #d4 ,,table4--#ajjkilogs4 ,soda ,lye containing #bj parts ,water with a corresponding boiling point of #bbj deg4 ,cent4 absorb ,steam as follows3 ---------------------------------------- ----------------------- ,final pressure in condenser4 ----------------------------------,press ure in ,corresponding #j atm4 #a atm4 #a atm4steam boiler4 temperature4 ---------------------------------------- ----------------------- #hj kil4#abe kil4#bjj kil4#cej kil4 #b atm4 #acf4j deg4 ,c4 #fe #hh #acj #aij #c #adc4j #ea #gj #ih #abe #d #aec4c #da #eh #hj #ajj #e #afj4j #cd #dh #ff #hj #f #aff4e #bg #dj #ee #gj #g #agb4a #bb #cc #dg #fj #h #agg4d #ai #bh #da #eb #i #ahb4j #af #bd #ce #df #aj #ahf4j #ab #ah #bh #ce #ab #aic4g #i #ad #bb #cc #ae #bjj4j #b #h #ab #ba #bj #bae4j ---------------------------------------- -------------------- ,not the least important part of the process with regard to its economy is the boiling down of the soda lye in order to bring it back to the degree of concentration which is required at the beginning of the process4 ,this is done in fixed boilers at a station from which the engines start on their daily service1 and to which they return for the purpose of being refilled with concentrated soda lye4 ,it is clear that a closed soda vessel has produced as much steam when the process is over as it has absorbed1 and the quantity of coal required for the evaporation of water in concentrating the soda lye can therefore be directly compared with that required in an ordinary engine for the production of an equal quantity of steam4 ,the boiling down of the soda lye requires1 according to its degree of concentration1 more coal than the evaporation of water does under equal circumstances1 and disregarding certain advantages which the new engine offers in the economy of the use of steam1 a greater consumption of coal must be expected4 ,but even at the small installation for the ,aix la ,chapelle-,burtscheid tramway with only two boilers of four square meters heating surface each1 made of cast iron #bj mm4 thick1 #a kilog4 of coal converts #f kilogs4 of water contained in the soda lye into steam1 while in an ordinary locomotive engine of most modern construction the effect produced is not greater than #a in #aj4 ,there can be no doubt that better results could be obtained if the installation were larger1 the construction of the boilers more scientific1 and their material copper instead of cast iron2 but even without such improvements the cost of boiling down the soda lye might be greatly lessened by the use of cheaper fuel than that which is used in locomotive engines1 and by the saving in stokers' wages1 since stokers would not be required to accompany the engines4 ,illustration3 ,,fig4 #e ,illustration3 ,,fig4 #f ,apart from these considerations1 the ,honigmann engines have the great advantage that neither smoke nor steam is ejected from them1 and that they work noiselessly4 ,the cost of the caustic soda does not form an important item in the economy of the process1 as no decrease of the original quantities had been ascertained after a service of four months duration4 ,besides the passenger engine already referred to1 which was tested by ,herr ,heusinger von ,waldegg#d in ,march1 #ahhd1 and which since then does regular service on the ,stolberg-,wurselen ,railway1 there are on the ,aix la ,chapelle-,julich railway two engines of #de1jjj kilogs4 weight in regular use1 which are intended for the service on the ,st4 ,gothard ,railway4 ,their construction is illustrated in ,figs4 #g and #i1 and other data are given in a report by the chief engineer of the ,aix la ,chapelle-,julich ,railway1 ,herr ,pulzner1 which runs as follows3 ,wurselen1 ,dec4 #bc1 #ahhd4 ,footnote #d3 ,z4d4,v4,d4,i41 #ahhd1 p4 #igh ,illustration3 ,,diagrams ,,for ,,the ,,calculation ,,of ,,stresses ,,in ,,bowstring ,,girders4 ,a trial trip was arranged on the line ,haaren-,wurselen1 the hardest section of the ,aix la ,chapelle-,julich ,railway4 ,this section has a gradient of #a in #fe on a length of #d kilos2 and two curves of #bej and #cjj meters radius and #ffg meters length4 ,the goods train consisted of twenty-two goods wagons1 sixteen of which were empty and six loaded4 ,the total weight of the wagons was #aia1gbj kilogs41 and this train was drawn by the soda engine with ease and within the regulation time1 while the steam pressure was almost constant1 viz41 five atmospheres4 ,the greatest load admissible for the coal burning engines of #de1jjj kilogs4 weight on the same section is #ahj1jjj kilogs4 ,illustration3 ,,fig4 #g4 ,illustration3 ,,fig4 #h4 ,proof is therefore given that the soda engine has a working capacity which is at least equal to that of the coal burning engine4 ,the heating surface of the soda engine1 moreover1 is #he square meters1 while that of the corresponding new ,henschel engine is #ib square meters4 ,on a former occasion ,i have already stated that the soda engine is capable not only of performing powerful work and of producing a large quantity of steam during a short time1 but also of travelling long distances with the same quantity of soda4 ,thus1 for example1 a regular passenger train1 with military transport of ten carriages1 was conveyed on ,nov4 #f1 #ahhd1 from ,aix la ,chapelle to ,julich and back1 i4e41 a distance of #de kilos1 by means of the fireless engine4 ,the gradients on this line are #a in #ajj1 #a in #hj1 and #a in #fe1 being a total elevation of about #bjj meters4 ,for a performance like this a powerful engine is required1 and a proof of it can be recognized in the consumption of steam during the journey1 for the quantity of water evaporated and absorbed by #d to #e cubic meters soda lye was #f1ejj liters4 ,another certificate concerning the tramway engine illustrated in ,figs4 #e and #f is of equal interest1 and runs as follows3 ,aix la ,chapelle1 ,jan4 #e1 #ahhe4 ,a fireless soda engine1 together with evaporating apparatus1 has been at work on the ,aix la ,chapelle-,burtscheid tramway for the last half year4 ,in order to test the working capacity of this locomotive engine1 and the consumption of fuel on a certain day1 the ,honigmann locomotive engine was put to work this day from #h3de o'clock a4m4 till #h o'clock p4m41 with a pause of three-quarters of an hour for the second quantity of soda lye4 ,the engine was1 therefore1 at work for fully #aj hours1 viz41 #e hours1 with the first quantity1 and five with the second4 ,the distance between ,heinrichsalle and ,wilhelmstrasse1 where the engine performed the regular service1 is #a kilo1 and there are gradients ,of about #a in #cj in #djj meter length4 #a #de #bej #a #gb #cej ,this distance was traversed sixty-four times1 the total distance1 including the journeys to the station1 being #ff kilos4 ,the engine gives off fully #ae-;horse power on the steepest gradient1 the total traction weight being #h to #i tons2 it is worked with an average steam pressure of #e atmospheres1 and has cylinders of #ahj mm4 diameter and #bbj mm4 stroke1 cog wheel-gear of #b to #c1 and driving wheels of #gjj mm4 diameter4 ,the quantity of water evaporated during the service time of #aj hours was found to be about #a1fjj kilogs41 consequently about #hjj kilogs4 steam was absorbed by one quantity of soda1 the weight of which was ascertained at about #a1ajj kilogs4 ,the averaging heating surface is #i4h square meters2 the difference of temperature between soda lye and water was toward the end only #c deg4 ,cent42 #bcd kilogs4 pitcoal were used for boiling down the lye for the #aj hours' service1 which corresponds to a #f4f fold evaporation4 7,signed7 ,m4,f4 ,,gutermuth1 ,assistant for ,engineering at the ,technical ,high ,school4 ,,haselmann1 ,manager of the ,aix la ,chapelle-,burtscheid ,tramway4 ,here are some unquestionable results4 ,for nearly a year the first railway engine1 and for six months the first tramway engine of this new construction1 have been introduced into regular public service1 and been open to public inspection as well as to the criticism of the scientific world4 ,they are worked with greater ease and simplicity than ordinary locomotive engines2 the economy of their working appears1 allowing for shortcomings unavoidably attached to small establishments1 to be at least equally great3 they do not emit either steam or smoke1 and their action is as noiseless as that of stationary engines4 ,in view of these facts it might be expected that railway managers1 who are continually told that the smoke of their engines is a serious annoyance to the public1 would be eager to make themselves acquainted with them2 it might1 in particular1 be expected that the managers of the underground and suburban railways of this metropolis would lose no time in making experiments on their own lines--if only by converting some of their old engines into those of the fireless system--and assist a little in the development of an invention1 in the success of which they have a tangible interest which is much greater than that of any railway on the ,continent1 but there is no sign yet of their having done anything4--,e41 in ,the ,engineer4 99 99 99 99 99 ,,simple ,,methods ,,of ,,calculating ,,stresses ,,in ,,girders4 ,by ,,charles ,,lean1 ,m4 ,inst4 ,c4,e4 ,bowstring ,girders4--,having had occasion to get out the stresses in girders of the bowstring form1 the author was not satisfied with the common formul for the diagonal braces1 which1 owing to the difficulty of apportioning the stresses amongst five members meeting in one point1 were to a large extent based on an assumption as to the course taken by the stresses4 ,as far as he could ascertain it1 the ordinary method was to assume that one set of diagonals1 or those inclined1 say1 to the right-hand1 acted at one time1 and those inclined in the opposite direction at another time1 and1 in making the calculations1 the apportionment of the stresses was effected by omitting one set4 ,calculations made in this way give results which would justify the common method adopted in the construction of bowstring girders1 viz41 of bracing the verticals and leaving the diagonal unbraced2 but an inspection of many existing examples of these bridges during the passing of the live load showed that there was something defective in them4 ,the long unbraced ties vibrated considerably1 and evidently got slack during a part of the time that the live load was passing over the bridge4 ,in order to get some definite formul for these girders free from any assumed conditions as to the course taken by the stresses1 or their apportionment amongst the several members meeting at each joint1 the author adopted the following method1 which1 he believes1 has not hitherto been used by engineers3 ,let ,fig4 #a represent a bowstring girder1 the stresses in which it is desired to ascertain under the loads shown on it by the circles1 the figures in the small circles representing the dead load per bay1 and that in the large circle the total of live and dead load per bay of the main girders4 ,a girder1 ,fig4 #a;,a1 with parallel flanges1 verticals1 and diagonals1 and depth equal to the length of one bay1 was drawn with the same loading as the bowstring4 ,the stresses in the flanges were taken out1 as shown in the figure1 keeping separate those caused by diagonals inclined to the left from those caused by diagonals inclined to the right4 ,the vertical component of the stress in the end bay of the top flange of the bowstring girder1 ,fig4 #a1 was1 of course1 equal to the pressure on the abutment1 and the stress in the first bay of the bottom flange and the horizontal component of the stress in the first bay of the top flange was obtained by multiplying this pressure by the length of the bay and dividing by the length of the first vertical4 ,the horizontal component of the stress in any other bay of the top or bottom flange of the bowstring girder--,fig4 #a--was found by adding together the product of the stress in the parallel flanged girder1 caused by diagonals inclining to the right1 divided by the depth of the bowstring girder at the left of the bay1 and multiplied by the depth of the parallel flanged girder2 and the product of the stress caused by diagonals inclining to the left divided by the depth of the bowstring girder at the right of the bay1 multiplied by the depth of the parallel flanged girder4 ,thus the horizontal component of the stress in ,d ,stress caused by diagonals ,length of right ,depth of parallel leaning to left4 vertical4 flanged girder4 #ae4ge #a_/d4e #aj ,stress caused by diagonals ,length of ver- ,depth of parallel leaning to right4 tical to left4 flanged girder4 #bd #a_/h #aj #fe2 and the vertical component ,horizontal component4 ,length of bay4 #fe #a_/aj 7#h4j - #d4e7 #bb4ge4 ,in the same way the horizontal and vertical components of the stresses in each of the other bays of the flanges of the bowstring were found2 and the stresses in the verticals and diagonals were found by addition1 subtraction1 and reduction4 ,these calculations are shown on the table1 ,fig #a;,b4 ,the result of this is a complete set of stresses in all the members of the bowstring girder--see ,fig4 #b--which produce a state of equilibrium at each point4 ,the fact that this state of equilibrium is produced proves conclusively that the rule above described and thus applied1 although possibly it may be considered empirical1 results in the correct solution of the question1 and that the stresses shown are actually those which the girder would have to sustain under the given position of the live load4 ,figs4 #b to #aj inclusive show stresses arrived at in this manner for every position of the live load4 ,an inspection of these diagrams shows3 a4 ,that there is no single instance of compression in a vertical member of the bowstring girder1 b4 ,that every one of the diagonals is subjected to compression at some point or other in the passage of the live load over the bridge1 c4 ,that the maximum horizontal component of the stresses in each of the diagonals is a constant quantity1 not only for tension and compression1 but for all the diagonals4 ,the diagrams also show the following facts1 which are1 however1 recognized in the common formul3 d4 ,the maximum stress in any vertical is equal to the sum of the amounts of the live and dead loads per bay of the girder4 e4 ,the maximum horizontal component of the stresses in any bay of the top flange is the same for each bay1 and is equal to the maximum stress in the bottom flange4 ,having taken out the stresses in several forms of bowstring girders1 differing from each other in the proportion of depth to span1 the number of bays in the girder1 and the amounts and ratios of the live and dead loads1 similar results were invariably found1 and a consideration of the various sets of calculations resulted in the following empirical rule for the stresses in the diagonals3 ,the horizontal component of the greatest stress in any diagonal1 which will be both compressive and tensile1 and is the same for every diagonal brace in the girder1 is equal to the amount of the live load per bay multiplied by the span of the girder1 and divided by sixteen times the depth of girder at center4 ,the following formul will give all the stresses in the bowstring girder1 without the necessity of any diagrams1 or basing any calculations on the assumed action of any of the members of the girders3 ,let ,s span of girder4 ,d depth at center4 ,b length of one bay4 ,n number of bays4 ,l length of any bay of top flange4 l length of any diagonal4 w dead load per bay of girder4 w live load per bay of girder4 ,w total load per bay of girder w w4 ,then3 ,s_/,b ,n4 ,bottom ,flange4 ,,wns_/#h;,d maximum stress throughout4 7#a7 ,top ,flange4--,in any bay the maximum stress ,,wns_/#h;,d ,l_/,b ,,wln_/#h;,d 7#b7 ,verticals4--,the maximum stress -,w4 7#c7 ,diagonals4--,the maximum stress is wl,s_/#af;,,db wl,n_/#af;,d 7#d7 ,these results show that the method generally adopted in the construction of bowstring girders is erroneous2 and one consequence of the method is the observed looseness and rattling of the long embraced ties referred to at the commencement of the article during the passage of the live load2 the fact being that they have at such times to sustain a compressive stress1 which slightly buckles them1 and sets them vibrating when they recover their original position4 ,another necessity of the common method of construction is the use of an unnecessary quantity of metal in the diagonals2 for1 by leaving them unbraced1 the set of diagonals which does act is subjected to exactly twice the stress which would be caused in it if the bridge was properly constructed4 ,a comparison of the results of a set of calculations on the common plan with those given in this paper1 shows at once that this is the case2 for the ordinary system of calculation the stresses1 in addition to showing compression in the verticals1 gives exactly twice the amount of tension in the diagonals which they should have4 ,,fig4 #a;,b4 ,top ,flange ,stresses4 ,stresses in ,diagonals4 ,hor4 ,ver4 ,c #ca4e #aj_/d4e #gj4jj #ca4ej a #gj -#fe #e4jj #b4be #ae4ge #aj_/d4e #ce b -#e4jj #d4jj ,d #fe4jj #bb4ge c #fe -#eh4cc-e #a4fg #a4cc _/ #bd #aj_/h #cj d -#a4fg #a4ge ,e #eh4cc #ad4eh e #eh4cc-ee4hc-a4fg 4#hc 4#hh _/ #bi4ge #aj_/aj4e #bh4cc f - 4#hc #a4ja ,f #ee4hc #h4cg g #ee4hc-ed4ej- 4#hc 4#ej 4#ei _/ #cc #aj_/ab #bg4e h - 4#ej 4#fa ,g #ed4ej #b4gb i #ed4ej-ec4fg- 4#ej 4#cc 4#dc _/ #cc4ge #aj_/ab4e #bg j - 4#cc 4#da ,h #ec4fg #b4fh k #ec4fg-ec4ji- 4#cc 4#bd 4#bh _/ #cb #aj_/ab #bf4fg l - 4#bd 4#bd ,i #ec4ji #g4ig m #ec4ji-eb4fg- 4#bd 4#ah 4#bj _/ #bg4ge #aj_/aj4e #bf4db n 4#ah 4#af ,j #eb4fg #ac4ag o #eb4fg-eb4cf- 4#ah 4#ac 4#aa _/ #ba #aj_/h #bf4be p - 4#ac 4#jf ,k #eb4cf #ah4cc _/ #aa4ge #aj_/d4e #bf4aa ,l #bc4e #aj_/d4e #eb4bb #bc4ej ,bottom ,flange ,stresses4 ,stresses in ,verticals4 ,hor4 ,ver4 ,m same as ,c #gj4jj r #ae - #d - #aa4jj ,n ,d #fe4jj s #e #b4be - #a4ge - #e4ej ,o ,e #eh4cc t #e #a4cc - #a4ja - #e4cb ,p ,f #ee4hc u #e 4#hh - 4#fa - #e4bg ,q ,g #ed4ej v #e 4#ei - 4#da - #e4ah ,r ,h #ec4fg w #e 4#dc - 4#bd - #e4ai ,s ,i #ec4ji x #e 4#bh - 4#af - #e4ab ,t ,j #eb4fg y #e 4#bj - 4#jf - #e4ad ,u ,k #eb4cf z #e 4#aa - #e4aa ,v ,l #eb4bb --,the ,engineer4 99 99 99 99 99 ,a ,,spring ,,motor4 ,an exhibition of a spring car motor was given at a recent date at the works of the ,united ,states ,spring ,motor ,construction ,company1 ,twelfth ,street and ,montgomery ,avenue4 ,as a practical illustration of the operation of the motor a large platform car1 containing a number of invited guests and representatives of the press1 was propelled on a track the length of the shop4 7,this was in #ahhc47 ,the engine1 if such it may be called1 was of the size which is intended to be used on elevated railways4 ,as constructed1 the motor combines with a stationary shaft a series of drums1 carrying springs1 and arranged so that they can be brought into use singly or in pairs4 ,each spring or section has sufficient capacity to run the car1 and thus as one spring is used another is applied4 ,there is a series of clutches by which the drums to which the springs are attached are connected1 with a master wheel1 which transmits through a train of wheels the power of the springs to the axles1 of the truck wheels4 ,the motor will be so constructed that it may be placed on a truck of the width of the cars at present in use1 and will be nine feet long1 with four traction wheels4 ,it is proposed do away with the two front wheels and platform1 so that the front of the car may rest on a spring to the truck4 ,there will be an engine at each end of the road1 which1 it is calculated1 will wind up the springs in at least two minutes' time4 ,while the mere construction of such a working motor involved nothing new1 the real problem involved consisted of the rolling of a piece of steel #cjj feet long1 #f inches wide1 and a quarter of an inch thick4 ,another element was the coiling of this strip of steel preliminary to tempering4 ,to temper it straight was to expose the grain to unnecessary strain when wound in a close coil4 ,to overcome this was the most difficult part of the work4 ,at the exhibition the inventor gave an illustration of the method which has been employed by the company4 ,the strip of steel is slowly passed through a retort heated by the admixture of gas and air at the point of ignition in proportions to produce intense heat4 ,when the strip has been brought to almost a white heat1 it is passed between two rollers of the coiling machine4 ,it is then subjected to a powerful blast of compressed air and sprays of water1 so that six inches from the machine the steel is cold enough for the hand to be placed on it4 ,after this operation the spring is complete and ready to be placed on the shaft4 ,the use of the springs is said to be beyond estimate4 ,they may be employed to operate passenger elevators1 the springs being wound by a hand crank4 ,it is understood that the ,french ,government has applied for them for running small yachts for harbor service4 ,among the advantages claimed for this motor are its cheapness in first cost and in operating expenses4 ,it is estimated that an engine of twenty-five horse power will be required at the station to wind the springs4 ,if there be one at each end of the line1 the cost for fuel1 engineer1 and interest will not exceed #ajj per week4 ,this will answer for fifty or any additional number of cars4 ,the company claims that by using twelve springs1 each #aej feet in length1 an ordinary street car can be driven about twenty miles4--,phil4 ,inquirer4 99 99 99 99 99 ,,casting ,,chilled ,,car ,,wheels4 ,we show herewith the method employed by the ,baltimore ,car ,wheel ,company in casting chilled wheels to prevent tread defects4 ,the ordinary mode of pouring from the ladle into the hub part of the mould1 and then letting the metal overpour down the brackets to the chill1 produces cold shot1 seams1 etc4 ,in the arrangement here shown the hub core1 ,a1 has a concave top1 ,b1 and the core seat1 ,c1 is convex1 its center part being lower than the perimeter of the top of the core4 ,figs4 #c1 #d1 show the core1 ,a1 in the side elevation and in plain4 ,fig4 #b is a core point forming a space to connect the receiving chamber1 ,e1 above1 with the mould by passageways1 ,d ,d1 formed in the side of the top of the core4 ,the combined area of these passageways being less than that of the conduit1 ,f1 from the receiving chamber1 the metal is skimmed of impurities1 and the latter are retained in the receiving chamber1 ,e4 ,the entering metal flows first to the lower hub part at ,h ,h1 thence by the sprue-ways1 ,g ,g1 to the lower rim part at ,j ,j1 being again skimmed at the mouth of the sprue-ways4 ,thus the rim fills as rapidly as the hub1 and the metal is of a uniform and high temperature when it reaches the chill4 ,illustration3 ,,casting ,,of ,,car ,,wheels4 ,in the wheels made by this firm1 every alternate rib is connected with the rim1 and runs off to nothing near the hub2 the intermediate ribs are attached to the hub1 and diminish in width toward the rim4--,jour4 ,railway ,app4 99 99 99 99 99 ,,electricity ,,and ,,prestidigitation4 ,the wonderful ease with which electricity adapts itself to the production of mechanical1 calorific1 and luminious effects at a distance1 long ago gave rise to the idea of applying it to certain curious and amusing effects that simple minds willingly style supernatural1 because of their powerlessness to find a satisfactory explanation of them4 ,illustration3 ,,fig4 #a4--,,rapping ,,and ,,talking ,,table4 ,who has not seen1 of old1 ,robert ,houdin's heavy chest and ,robert ,houdin's magic drum8 ,these two curious experiments are1 as well known1 founded upon the properties of electro-magnets4 ,at present we shall make known two other arrangements1 which are based upon the same action1 and which1 presenting old experiments under a new form1 rejuvenate them by giving them another interest4 ,the first apparatus 7,fig4 #a71 which presents the appearance of an ordinary round center table1 permits of reproducing at will the spirit rappings and sepulchral voice experiments4 ,the table support contains a ,leclanche pile1 of compact form1 carefully hidden in the part that connects the three legs4 ,the top of the table is in two parts1 the lower of which is hollow1 and the upper forms a cover three or four millimeters in thickness4 ,in the center of the hollow part is placed a vertical electro-magnet1 one of the wires of which communicates with one of the poles of the pile1 and the other with a flat metallic circle glued to the cover of the table4 ,beneath this circle1 and at a slight distance from it1 there is a toothed circle1 ,f1 connected with the other pole of the pile4 ,when the table is pressed lightly upon1 the cover bends and the flat circle touches the toothed one1 closes the circuit of the pile upon the electro-magnet1 which latter attracts its armature and produces a sharp blow4 ,on raising the hand1 the cover takes its initial position1 breaks the circuit anew1 and produces another sharp blow4 ,upon running the hand lightly over the table1 the cover is caused to bend successively over a certain portion of its circumference1 contacts and breakages of the circuit are produced upon a certain number of the teeth1 and the sharp blow is replaced by a quick succession of sounds1 or a tremulous one1 according to the skill of the medium whose business it is to interrogate the spirits4 ,as the table contains within it all the mechanism that actuates it1 it may be moved about without allowing the artifice to be suspected4 ,illustration3 ,,fig4 #b4--;,,electric ,,insects4 ,the table may also be operated at a distance by employing conductors passing through the legs and under the carpet and communicating with a pile whose circuit is closed at an opportune moment by a confederate located in a neighboring apartment4 ,finally1 on substituting a small telephone receiver for the electro-magnet1 and a microtelephone system for the ordinary pile1 we shall convert the rapping spirits into talking ones4 ,with a little exercise it will be easy for the confederate to transmit the conversation of the spirits in employing sepulchral tones to complete the illusion4 ,fig4 #b represents a device especially designed as a parlor ornament4 ,when the plant is touched1 the insects resting upon it immediately begin to flap their wings as if they desired to fly away4 ,these insects are actuated by a ,leclanche pile hidden in the pot that contains the plant4 ,the insect itself is nothing else than a mechanism analogous to that of an ordinary vibrating bell4 ,the body forms the core of a straight electro-magnet1 c1 which is bent at right angles at its upper part1 and in front of which is placed a small iron disk1 b1 forming the animal's head4 ,this head is fixed upon a spring1 like the armature of ordinary bells1 and causes the wings to move to and fro when it is successively attracted and freed by the electro-magnet4 ,the current is interrupted by means of a small vibrating device whose mode of operation may be easily understood by glancing at the section in ,fig4 #b4 ,the current enters the electro-magnet through a fine copper wire hidden in the leaves and connected with the positive pole of the pile4 ,the negative pole is connected with the bottom of the pot4 ,the wire from the vibrator of each insect reaches the bottom of the flower-pot1 but does not touch it4 ,a drop of mercury occupies the bottom of the pot1 where it is free to move about4 ,it results that if the pot be taken into the hand1 the exceedingly mobile mercury will roll over the bottom and close the circuit successively on the different insects1 and keep them in motion until the pot has been put down and the drop of mercury has become immovable4 99 99 99 99 99 ,,portable ,,electric ,,safety ,,lamps4 ,one of the most difficult problems that daily presents itself in large cities is how to proceed without danger in the search for leakages in gas mains1 or in attempts to save life in houses accidentally filled with explosive gases4 ,the introduction of a flame into such places leads in the majority of cases to accidents whose consequences cannot be estimated4 ,the reader will remember especially the explosion which occurred some time ago in ,st4 ,denis ,street1 ,paris1 and which killed a considerable number of persons4 ,it has1 therefore1 been but natural to think of the use of electricity1 which gives a bright line without a flame1 in order to allow life-saving corps and firemen to enter buildings filled with an explosive mixture1 without any risk whatever4 ,illustration3 ,,fig4 #a4--;,,elevation 7,scale #a_/be74 ,several electricians have proposed ingenious portable apparatus for this purpose1 and1 among these1 ,mr4 ,a4 ,gerard1 whose device we illustrate herewith4 ,in this system the electric generator is stationary1 and remains outside the building4 ,this1 along with all the rest of the apparatus1 is mounted upon a carriage4 ,the operator1 instead of carrying a pile to feed the lamp1 drags after him a very elastic cable containing the two conductors4 ,this ,ariadne's thread easily follows all sinuosities1 and adapts itself to all circumvolutions4 ,the entire apparatus1 being mounted upon a carriage1 can be easily drawn to the place of accident like a fire engine4 ,illustration3 ,,fig4 #b4--,,plan 7,scale #a_/be74 ,general ,description4--,fig4 #a shows the carriage4 ,in the center1 over the axle1 is mounted a dynamo-electric1 machine1 ,d1 driven by a series of gear wheels that are revolved by winches1 ,,mm4 ,upon the shaft1 ,a1 is fixed a hand wheel1 ,v1 designed to regulate the motion4 ,in the forepart of the carriage are placed two windlasses1 ,,tt1 permanently connected with the terminals of the dynamo4 ,upon each of these is wound a cable formed of two conductors1 insulated with caoutchouc and confined in the same sheath4 ,each windlass is provided with five hundred feet of this cable1 the extremity of which is attached to two lanterns each containing an incandescent lamp4 ,these lanterns1 are inclosed in boxes1 ,,bb1 with double sides1 and cross braced with springs so as to diminish shocks4 ,under the windlass there is a case which is divided into two compartments1 one of which contains tools and fittings1 and the other1 six carefully packed incandescent lamps1 to be used in case of accident to the lanterns4 ,at the rear end of the carriage there is a hinged bar1 ,c1 designed to support it at this point and give it greater stability during the maneuvers4 ,the stability is further increased by chocking the wheels4 ,illustration3 ,,fig4 #c4--;,,hand ,,lantern 7,scale #a_/d74 ,maneuver of the ,apparatus4--,the carriage1 having reached the place of accident1 is put in place1 its rear end is supported by the bar1 ,c1 the wheels are chocked1 and the winches are placed upon the dynamo gearing4 ,two strong men selected for the purpose now seize the winches and begin to revolve them1 and the lamps immediately light while in their boxes4 ,another man1 having opened the latter1 takes out one of the lanterns and enters the dangerous place1 dragging after him the elastic cable that unwinds from the windlass4 ,two men are sufficient to turn the winches for five minutes2 with a force of six men to relieve one another the apparatus may therefore be run continuously4 ,illustration3 ,,fig4 #d4--,,pole ,,lantern 7,scale #a_/d74 ,the dynamo1 which is of strong and simple construction1 is inclosed in a cast iron drum1 and is consequently protected against accident4 ,with a power of #be kilogrammeters it furnishes a current of #dj volts and #g amperes1 which is more than sufficient to run two #ej-;candle incandescent lamps4 ,the winches are removable1 and are not put upon the shaft until the moment they are to be used4 ,the windlasses1 as above stated1 are permanently connected with the terminals of the dynamos4 ,the current is led to them through their bearings and journals4 ,their shaft is in two pieces1 insulated from one another4 ,one extremity of the cable is attached to these two pieces1 and the other to the lantern4 ,each windlass is provided with a small winch that allows the cable to be wound up quickly4 ,illustration3 ,,fig4 #e4--,,windlass 7,scale #a_/aj74 ,the two lanterns are different1 on account of the unlike uses to which they are to be put4 ,one of them is a hand-lamp that permits of making a quick preliminary exploration4 ,the second is to be fixed by a socket beneath it to a pole that is placed along the shafts of the carriage4 ,this lantern1 upon being thrust into a chimney1 shaft1 or well1 permits of a careful examination being made thereof4 ,as the handle terminates in a point2 it may be stuck into the ground1 to give a light at a sufficient height to illuminate the surroundings4 ,the hand lantern consists of a base1 ,p1 provided with three feet4 ,at the top there is a threaded circle to which is attached a movable handle1 ,k1 that is screwed on to a ring1 ,c4 ,these three pieces1 which are of bronze1 are connected by #ab steel braces1 ,e1 that form a protection for the glass1 ,m4 ,the lantern is closed above by a thick glass disk1 ,g4 ,the luminous rays are therefore capable of spreading in all directions4 ,tight joints are formed at every point by rubber or leather washers4 ,illustration3 ,,fig4 #f4--,,lantern ,,box 7,scale #a_/aj74 ,in the center of the lantern is placed the incandescent lamp4 ,this is held in a socket1 and is provided with two armatures to which the platinum wires are soldered4 ,two terminals1 b1 are affixed to the lamp socket4 ,beneath the lantern there is a cylindrical box provided with a screw cap4 ,in one side of this box there is a tubulure that gives passage to the electric cable whose conductors are fastened to the terminals4 ,a conical rubber sleeve1 ,r1 incloses the cable1 which is pressed by the screw cap1 ,s4 ,a special spring1 ,y1 attached at one end to the top of the lantern1 and at the other to the cable1 ,x1 is designed to deaden the too sudden shocks that the lantern might be submitted to1 and that would tend to pull out the cable4 ,as a result of the peculiar arrangement of this lantern1 the lamp is constantly surrounded with a certain quantity of air that would certainly suffice to consume the carbons in case of a breakage of the globe without allowing any lighted particles to escape to the exterior4 ,besides1 should the terminals become unscrewed1 and should the conductors thus rendered free produce sparks1 the latter would be prevented from reaching the exterior by reason of the absolute tightness of the box4 ,in case the incandescent lamp should get broken1 the only inconvenience that would attend the accident would be that the man who held the lantern would be for a moment in the dark4 ,when he reached the carriage1 it would be only necessary for him to take off the glass disk1 take the broken lamp out of its socket1 insert a new one1 and then put the glass top on again4--,le ,gnie ,civil4 99 99 99 99 99 ,voltaic batteries containing solutions of ammonium chloride and zinc chloride can1 according to the recent researches of ,m4 ,onimus1 be converted into dry piles by mixing these solutions with plaster of ,paris1 and allowing the mixture to solidify4 ,if mixtures of ferric oxide and manganese peroxide with plaster of ,paris are employed1 the electromotive force is slightly higher than with plaster of ,paris alone2 and when ferric oxide is used1 the battery quickly regains its original strength on breaking the circuit4 ,when the battery is exhausted1 the solid plaster of ,paris has simply to be moistened again with the solution4 99 99 99 99 99 ,,the ,,electric ,,discharge ,,and ,,spark ,,photographed ,,directly ,,without ,,an ,,objective4 ,the study of the form and color that electric discharges exhibit1 according to the different ways in which they are produced1 has already enticed a certain number of amateurs and scientists4 ,every one knows the remarkable researches of the lamented ,th4 ,du ,moncel on the induction spark1 and during the course of which he1 in #ahec1 discovered that phenomenon of the electric efflux which has since been the object of important researches on the part of several physicists and chemists1 among whom must be cited ,messrs4 ,thenard1 ,hautefeuille1 and ,chapuis4 ,twenty years ago1 ,mr4 ,bertin1 who was then ,professor at the ,faculty of ,strassburg1 and who was afterward subdirector of the normal school1 was directing his researches upon the electric discharges produced by high tension apparatus1 plate machines1 and ,leyden jars4 ,he thought1 with reason1 that1 on account of its rapidity and complexity1 a portion of the phenomenon must escape the eye of the observer1 and so the idea occurred to him to photograph the discharge in order to afterward study its forms more at his leisure4 ,we have recently had an opportunity of seeing a negative which was obtained by him at that epoch2 but the photographic processes then in use probably did not allow him to obtain others that were as satisfactory1 and he had given up this kind of study1 when1 last year1 he had an opportunity of speaking of it to the well known manufacturer ,mr4 ,f4 ,ducretet1 whom he induced to take it up and employ the new gelatino-bromide process4 ,unfortunately1 he died before these experiments were begun1 and was unable to see the realization of his project4 ,mr4 ,ducretet did not abandon the idea1 but constructed the necessary apparatus1 and obtained the results that we now place before our readers4 ,illustration3 ,,fig #a4 ,his apparatus1 which contains no photographic objective1 consists of an oblong case1 ,,abcd1 made of red glass and resting upon an ebonite table supported by one leg 7,fig4 #a74 ,in the top of the case1 as well as in the two sides1 ,,ad and ,,bc1 are apertures that are closed by ebonite cylinders through which slide1 with slight friction1 copper rods1 ,,hln4 ,in the leg of the table there is a copper rack which may be maneuvered from the interior by a pinion1 and which communicates electrically with a terminal1 ,e4 ,the upper part of this rack1 which enters the glass case1 is threaded1 so that there may be affixed to it either a metallic or an insulating disk4 ,the rods1 ,,hln1 are likewise threaded1 so that there may be affixed to their internal extremities balls1 points1 combs1 and disks of metal or of insulating material at will4 ,illustration3 ,,fig #b4 ,in short1 we have here a transparent box 7impermeable to photogenic rays7 into which electricity may be led by means of four conductors that are arranged two by two in a line with each other1 or in perpendicular positions1 and that may be made to approach or recede from one another by maneuvering them from the exterior4 ,this very simple arrangement answers every requirement1 and1 upon placing a sensitized plate in the vicinity of the conductors1 permits of photographing the electric discharge directly and1 so to speak1 before the eyes of the operator4 ,as a source of electricity1 use is made of a bichromate of potash battery of #f elements1 capable of giving #aj volts and #ae amperes4 ,the current from this battery is converted into a current of high tension by means of a strong induction coil capable of giving sparks more than eight inches in length4 ,the discharge shown in ,fig4 #d was obtained by means of a ,holtz machine4 ,each experiment lasted less than a second4 ,illustration3 ,,fig4 #c4 ,figs4 #b and #c represent the efflux that occurred under2 the following conditions3 ,the disk1 ,p1 was of metal1 and was connected with the negative pole of the induction coil2 and upon it was laid the photographic plate with the sensitized film downward1 and consequently touching the disk4 ,this is what produced the opaque circle in the center4 ,then the photographic plate was entirely covered with a thin ebonite plate1 above which there was a second one supported by small wedges1 so as to allow air to circulate between them4 ,finally1 upon this second ebonite plate there was placed another photographic plate1 with its sensitized film upward and directly in contact with an upper metallic disk1 and connected with the positive pole of the coil by the conductor1 ,l4 ,an inspection of ,figs4 #b and #c shows that the1 efflux does not possess the same form at the two poles4 ,we remark at the positive pole a quite wide opaque circle surrounded by a sort of aureola composed of an infinite number of very delicate rays1 while at the negative pole the aureola seems not to have been able to spread4 ,we see1 moreover1 the same phenomenon in examining ,fig4 #d 7which represents the efflux obtained by means of a ,holtz machine71 but this time in a horizontal direction4 ,the photographic plate was here placed upon the non-conducting disk1 ,p4 ,as the sensitized film was upward1 it was put in contact with the balls at the extremity of the conductors1 ,h and ,n4 ,illustration3 ,,fig4 #d4 ,it will be seen here again that the efflux spreads out widely at the positive pole1 while it is contracted at the other4 ,the conducting balls were spaced #j4jd inch apart4 ,a spark leaped from one to the other at the moment the current was being interrupted4 ,in ,fig4 #e we are enabled to study with more ease a spark obtained with nearly the same arrangement4 ,the balls1 ,h and ,n1 did not here rest directly upon the sensitized film1 but upon two small sheets of tin cemented to the extremities of the plate at #j4jf inch apart4 ,in addition1 the source employed was not the ,holtz machine1 but the pile with induction coil4 ,two nearly parallel sparks were obtained4 ,it will be seen that these are very complex4 ,each of them seems to be formed of four lines of different sizes1 entangled with one another and presenting different sinuosities4 ,aside from this1 the plate is traversed for a space of #j4jd of an inch by curved lines running from one pole to the other1 and exhibiting numerous sinuosities4 ,illustration3 ,,fig4 #e4 ,fig4 #f represents a discharge that occurred under the following circumstances3 ,the disk1 ,p1 being metallic and connected with one of the poles1 there was placed upon it a thin ebonite plate of the same dimensions as the photographic one1 and then the latter with the sensitized pellicle upward4 ,finally1 the pellicle was put in contact with the upper conductor1 ,l1 which terminated in a ball and was connected with the other pole of the induction coil4 ,it will be seen that1 despite the two dielectrics 7ebonite and glass7 interposed1 and the opacity of one of them1 the efflux that occurred around the disk1 ,p1 is quite sharply reproduced upon the sensitized plate by a circle like that which we observed in ,figs4 #b and #c4 ,it will be seen1 besides1 that an infinite number of ramifications in every direction has been produced around the ball1 and we can follow the travel of the spark that leaped between the ball and disk in two directions situated in the prolongation of one another4 ,under the two principal and clearly marked lines that this spark made there are seen two other1 very pale and much wider ones1 that present no sinuosities parallel with the first4 ,the results of these experiments are very curious4 ,the position of the plates was varied in #ah different ways1 as was also the form of the conductors4 ,we have spoken of those only that appear to us to present the most interest4 ,unfortunately1 notwithstanding the skill of the engraver1 it is impossible to render with accuracy all the details that are seen upon examining the negative4 ,the proofs that have been printed upon paper present much less sharpness than the negative1 for there are certain parts of the figures on the glass that do not show in the print4 ,illustration3 ,,fig4 #f4 ,we have been content here to make known the results obtained1 without drawing any conclusions from them4 ,it is to be hoped that these experiments1 which can be easily repeated by means of the apparatus described above1 will be repeated and discussed by electricians1 and that they will contribute toward making known to us the nature of the mysterious agent that will give its name to our era4--,g4 ,mareschal1 in ,la ,lumiere ,electrique4 99 99 99 99 99 ,,the ,,true ,,constant ,,of ,,gravity4 ,many of the readers of this journal may like to participate in the discussion of the following proposition4 ,the statement is this3 ,the space through which a body1 near the surface of the earth1 at mean latitude1 in vacuo1 descends by virtue of the accelerating force of gravity in #a_/ajjj of an hour is precisely #b1ejj geometric inches #ajj geometric cubits the side of a square geometric acre4 ,the geometric inch is taken1 in accordance with the view of ,sir ,john ,herschel1 at #a_/a1jjj1jjj1jjj of twice the polar axis of the earth1 and equals #a-a_/ajjj ,english inches very nearly4 ,the strict decimal relation of the proposition is shown by the following table4 ,it has been tested by ,clairaut's theorem1 and by other existing expressions1 and has been found to agree1 far within the probable limits of errors in observation1 with the most approved values of the constant4 ,in fact1 it is contained in the existing expressions2 but the decimal relation does not appear unless we state the unit of linear measure as a decimal of the earth's semi-polar axis1 and1 at the same time1 divide the circle1 both for time and for general purposes1 geometrically1 i4e41 by strict decimalization upon the hour-angle4 ,a mathematical reason underlies the proposition4 ,time in ,acquired ,squares ,total ,ratio of ,descent in ,thousandths ,velocity1 of the ,descent1 ,spaces1 ,each ,successive of an ,hour4 ,cubits4 ,time4 ,cubits4 ,interval of ,intervals1 ,time4 ,cubits4 #a #bjj #a #ajj #a #ajj #b #djj #d #djj #c #cjj #c #fjj #i #ijj #e #ejj #d #hjj #af #a1fjj #g #gjj #e #a1jjj #be #b1ejj #i #ijj #f #a1bjj #cf #c1fjj #aa #a1ajj #g #a1djj #di #d1ijj #ac #a1cjj #h #a1fjj #fd #f1djj #ae #a1ejj #i #a1hjj #ha #h1ajj #ag #a1gjj #aj #b1jjj #ajj #aj1jjj #ai #a1ijj ,so that-- ,cubits4 ,acre ,sides4 ,in #a_/aj1jjj of an hour1 the total descent #a #a_/ajj ,in #a_/ajjj of an hour1 the total descent #ajj #a ,in #a_/ajj of an hour1 the total descent #aj1jjj #ajj ,and so on1 in strict decimal relation with the earth's semi-polar axis4 ,a two-fold reason why the constant for latitude #de is vastly better than any other1 is in its having this simple relation with the semi-axis1 and at the same time a less complex way of applying the correction for latitude4 ,,jacob ,m4 ,,clark4 ,new ,york1 ,february1 #ahhe4 99 99 99 99 99 ,,origin ,,of ,,thunderstorms4 ,at the recent congress of ,german medical men and physicists1 ,dr4 ,s4 ,hoppe1 of ,hamburg1 read a paper in which he sought to show that the electricity of thunderstorms is generated by the friction of vapor particles generated by the evaporation of water4 ,this opinion was strengthened by several experiments in which compressed cold air was allowed to rush into a copper vessel containing warm moist air1 thus generating a large amount of electricity4 ,he concludes that the rise of a column of warm moist air into the colder atmosphere above will be followed by a thunderstorm if it acquires sufficient velocity to prevent neutralization of the electricity generated by the friction of the air4 ,hence1 in his opinion1 open districts denuded of forests are more liable to thunderstorms than wooded regions1 where the trees forbid the rise of humid air currents4 99 99 99 99 99 ,,improvised ,,toys4 ,do our readers remember all those ingenious toys which our mothers and sisters improvised in order to amuse us8 ,we took a walk into the country1 and our eldest sister or our mother picked a wild poppy1 turned its red petals back and encircled them with a thread1 and stuck a sprig of grass into the seed vessel to represent a headdress of feathers4 ,here was a fresh and pretty doll 7,fig4 #a74 ,another day it was the season of lilacs4 ,the children gathered branches by the armful1 and from these the mother picked off the flowers and strung them one by one with a needle4 ,here was a bracelet or a necklace4 ,an acorn was picked up in the woods1 the mother carved it with a pen-knife1 and behold a basket4 ,from a nutshell she made a boat1 and from a green almond a rabbit4 ,sometimes she carved the rabbit's ears out of the almond itself1 but in most cases they were made from a pretty rose-colored radish4 ,illustration3 ,,fig4 #a4--;,doll made of a ,wild ,poppy4 ,do you remember the cork from which1 by the aid of a few long needles for bars1 an ingenious fly-cage was formed8 ,and the castle of cards1 four1 five1 and eight stories high8 ,and then those famous card tents in a row1 that fell one after another when the first one in the line was overturned8 ,illustration3 ,,fig4 #b4--;,hygrometric ,doll2 its ,dress ,colored with ,chloride of ,cobalt4 ,how we passed the evenings with our eyes fixed upon our mothers1 who patiently1 with their skillful scissors1 cut horses and dogs out of old white1 red1 and blue cards6 ,and how many plays1 without costing a cent1 served to amuse the children by exercising their ingenuity6 ,the mother marked at hazard five dots upon a sheet of paper4 ,the question was to draw a man1 one of the dots showing the place of the head and the other four the feet and hands4 ,illustration3 ,,fig4 #c4--,old ,man made of ,lobster's ,claws4 ,when the dessert was brought upon the table1 it became a question of manufacturing a head out of an orange4 ,that is not very difficult2 two holes for the eyes1 a large slit for the mouth1 and nothing easier than to simulate the teeth and nose4 ,the head was placed upon a napkin stretched over the top of a champagne glass4 ,this was one of our great amusements4 ,the napkin was drawn ultimately to the right and left1 and this moved the head and caused it to assume most comical positions4 ,but what caused irresistible laughter was when a sly hand pressed the head and made it open its mouth wide4 ,and then what pigs we manufactured with a lemon perched upon four matches6 ,illustration3 ,,fig4 #d4--;,crocus ,flowering in a ,perforated ,pot4 ,without mentioning ,chinese shadows1 how many cheap amusements there are that can be varied to infinity merely by various combinations of the fingers interlocked in diverse manners6 ,illustration3 ,,fig4 #e4--a4 ,paper ,cross4 #b4 ,method of ,making the ,cross4 #c4 ,rabbits ,made of ,green ,almonds4 #d4 ,basket ,made of ,sedges4 #e4 ,acorn ,basket4 #f4 ,fly-cage ,made of a ,cork4 ,all such amusements were much in vogue in former times1 but we are assured that to-day mothers are less conversant with these curious and droll inventions1 which were once transmitted like the tales of ,mother ,goose4 ,they buy playthings for their children at great expense1 and allow the latter to amuse themselves all by themselves4 ,the toy paid for and given1 the child is no longer in their mind4 ,those mothers who have preserved the traditions of these little pastimes1 and know how to skillfully vary them1 find therein so many resources for amusing their children4 ,then it is so pleasant to see the eyes of the latter eagerly fixed upon the scissors1 and to hear their exclamations of pleasure and their fresh laughter when the paper is transformed under expert fingers into a boat1 house1 or what not6 ,illustration3 ,,fig4 #f4--,the ,lesson in ,drawing4--,an ,illustrated ,five-spot of ,hearts4 ,it has required millions of mothers and nurses to put their wits to work to amuse their children in order to form that collection of charming combinations that at present constitutes a sort of science4 ,mr4 ,gaston ,tissandier not long ago conceived the happy idea of bringing together in an illustrated volume a description of some of these improvised toys and amusing plays1 and it is from this that the accompanying illustrations 7which sufficiently explain themselves7 are taken4 99 99 99 99 99 ,,the ,,olian ,,harp4 ,the olian harp is a musical instrument which is set in action by the wind4 ,the instrument1 which is not very well known1 is yet very curious1 and at the request of some of our readers we shall herewith give a description of it4 ,illustration3 ,,fig4 #a4--,,kircher',s ,,olian ,,harp4 ,according to a generally credited opinion1 it is to ,father ,kircher1 who devised so many ingenious machines in the seventeenth century1 that we owe the first systematically constructed model of an olian harp4 ,we must add1 however1 that the fact of the spontaneous resonance of certain musical instruments when exposed to a current of air had struck the observers of nature in times of remotest antiquity4 ,without dwelling upon the history of the olian harp1 we may say that in modern times this instrument has been especially constructed in ,england1 ,scotland1 ,germany1 and ,alsace4 ,the olian harp of the ,castle of ,baden ,baden1 and those of the four turrets of ,strassburg ,cathedral are celebrated4 ,illustration3 ,,fig4 #b4--;,,frost ,,kastner',s ,,improved ,,olian ,,harp4 ,we shall first describe ,kircher's harp1 which this ,jesuit savant constructed according to an observation made by ,porta in #aeeh4 ,the instrument consists of a rectangular box 7,fig4 #a71 the sounding board of which1 containing rose-shaped apertures1 is provided with a certain number of strings stretched over two bridges and fastened to pegs at the extremities4 ,this box carries a ring that serves for suspending it4 ,kircher recommends that the box be made of very sonorous fir wood1 like that employed in the construction of stringed instruments4 ,he would have it #a4jhe meters in length1 #j4dcd meter in width1 and #j4bag meter in height1 and would provide it with fifteen catgut strings1 tuned1 not like those of other instruments to the third1 fourth1 or fifth1 but all in unison or to the octave1 in order1 says he1 that its sound shall be very harmonious4 ,the experiments of ,kircher showed him the necessity of employing a sort of concentrator in order to increase the force of the wind1 and to obtain all the advantage possible from the current of air that was directed against the strings4 ,the place where the instrument is located should not1 according to him1 be exposed to the open air1 but must be a closed one4 ,the air1 nevertheless1 must have free access to it on both sides of the harp4 ,the force of the wind may be concentrated upon such a point in different ways2 either1 for example1 by means of conical channels1 or spiral ones like those used for causing sounds to reach the interior of a house from a more elevated place1 or by means of a sort of doors4 ,these latter1 two in number1 are adapted to a kind of receptacle made of boards and presenting the appearance of a small closet4 ,in the back part of this receptacle there is a slit1 and in front of this the harp is hung in a slightly oblique position4 ,the whole posterior portion of the apparatus must be situated in the apartment1 while the doors must remain outside the window 7,fig4 ,i74 ,in later times the olian harp has been improved by ,messrs4 ,frost and ,kastner1 whose apparatus is represented in ,fig4 #b4 ,it consists of a rectangular box with two sounding boards1 each provided with eight catgut strings4 ,in order to limit the current of air and to bring it with more force against the strings1 two wings are adapted near the thin surfaces opposed to the wind1 so that the current may reach each group of cords on passing through the narrow aperture between the obliquely inclined wing and the body of the instrument4 ,the dimensions of the resonant box are as follows3 height1 #a4bh meters2 width1 #j4bg meter2 and thickness1 #j4jge meter4 ,distance between the two bridges1 or length of the sonorous portion of the cords1 about #a meter2 width of the wings1 #j4ad meter4 ,distance between the sounding board and the wings1 #j4db meter4 ,inclination of the wings1 #ej degrees4 ,illustration3 ,,fig4 #c4--,,olian ,,harp ,,in ,,the ,,old ,,castle ,,of ,,baden ,,baden4 ,the celebrated olian harps of the old castle of ,baden ,baden are entirely different1 and merit description4 ,one of them 7,fig4 #c7 is formed of a resonant box1 the construction of which differs from that of olian harps with a rectangular box1 in that it is prolonged beyond the place occupied by the strings1 and is rounded off behind4 ,in the opposite side there are two long and narrow apertures4 ,to prevent the apparatus from being injured by the weather1 it is inclosed in a sort of case occupying the recess of the window in the old ruined castle in which it is exposed4 ,behind the harp there is a wire lattice door1 the purpose of which seems to be to protect the instrument against the attempts of robbers or the indiscreet contact of tourists4 ,we annex to the general view of the instrument a front and profile plan 7,fig4 #d74 ,the olian harp has often inspired both writers of prose and poetry4 ,chateaubriand1 in ,les ,natchez1 compares its sounds to the magic concerts that the celestial vaults resound4 ,without attributing such effects to the instrument1 it must be admitted that it possesses remarkable properties1 which act upon the nervous system and cause very different impressions1 according to the temperament of those who listen to its accords4 ,illustration3 ,,fig4 #d4--,,plan ,,of ,,the ,,baden ,,baden ,,instrument4 ,hector ,berlioz1 in his ,voyage ,musicale en ,italie1 has given as follows the curious effects that an olian harp produced upon his lively and impassioned imagination3 ,on one of those gloomy days that sadden the end of the year1 listen1 while reading ,ossian1 to the fantastic harmony of an olian harp swinging at the top of a tree deprived of verdure1 and ,i defy you not to experience a profound feeling of sadness and of abandon1 and a vague and infinite desire for another existence4 ,an ,english physician1 ,dr4 ,j4,m4 ,cox1 in his practical ,observations upon dementia1 asserts that unfortunate lunatics have been seen whose sensitiveness was such that ordinary means of cure had to be given up with them1 but who were instantly calmed by the sweet and varied accords of an olian harp4 ,other observers narrate that they have heard the efficacy of ,aeolian sounds spoken of in ,scotland for producing sleep4 ,telegraph wires are often1 under the influence of the winds1 submitted to vibrations which reproduce the phenomena of the ,aeolian harp4 ,the electric telegraph1 which1 before the construction of the ,kehl bridge1 directly traversed the ,rhine1 very frequently resounded1 and the observer who placed his ear against the poles on the bank of the river was enabled to hear something like a far-off sound of bells4--,la ,nature4 99 99 99 99 99 ,,physics ,,without ,,apparatus4 ,,manufacture ,,of ,,illuminating ,,gas4 ,illustration3 ,,fig4 #a4--,,production ,,of ,,illuminating ,,gas4 ,burn a piece of paper of about the size of the hand upon a clean porcelain plate1 and this will serve to show the phenomena of carbonization and the formation of empyreumatic products under the action of heat4 ,under the burned paper there will be found a yellowish deposit which sticks to the fingers1 and which consists of oil of paper produced by distillation4 ,an idea of the production of illuminating gas through the distillation of coal may be easily given by means a single clay pipe4 ,upon filling the bowl of this with fragments of coal1 closing the opening with clay1 and1 after the latter is dry1 placing the bowl in a coal fire so that the stem shall project1 gas will soon be observed issuing from1 the latter1 and1 when lighted1 will give a very bright flame4 ,if the pipe seems to be a little too costly1 recourse maybe had to a large piece of wrapping paper rolled into the form of a cornucopia1 and held in the left hand by means of the pointed end4 ,if1 after an aperture has been made in this near the point1 the base be lighted1 the heat developed by the flame will produce a sort of distillation of the organic matter of the paper1 and the empyreumatic and gaseous products will rise in the cone1 and make their exit through the orifice1 where they may be lighted with a match 7,fig4 #a74 ,it goes without saying that this experiment lasts but a few seconds2 but1 as short as this period is1 it is sufficient to give a demonstration of the production of illuminating gas through the distillation of organic matters4 ,care should be taken not to set anything on fire while performing it1 and it is well to operate over a pavement1 and far from any inflammable materials4 ,,elasticity ,,of ,,bodies4 ,illustration3 ,,fig4 #b4--;,,experiment ,,on ,,the ,,elasticity ,,of ,,bodies4 ,mould a piece of fresh bread with the fingers so as to give it the size and shape shown in ,fig4 #b4 ,if this object be placed upon a wooden table1 and a hard blow be given it with the fist1 it will be found impossible to put it permanently out of shape4 ,however hard be the blow1 the elastic material1 although flattened for an instant1 will always resume its original form4 ,if the object be thrown on the floor with all one's might1 the result will be the same2 its elasticity will always cause it to spring back to its original form4 ,the experiment will only succeed when the bread that is used is very fresh and soft4 99 99 99 99 99 ,,scientific ,,amusements4 ,the ,dance of the ,electrified ,puppets4--,we have already pointed out a means of obtaining electrical manifestations without recourse to a machine1 and shall now describe a very easily performed experiment--the dance of the electrified puppets4 ,illustration3 ,,fig4 #a4--;,,dance ,,of ,,the ,,electrified ,,puppets4 ,procure a pane of glass about #aj inches in width and #ad in length1 and support it between two large books1 as shown in ,fig4 #a4 ,the glass must be inserted in the books in such a way that it shall be an inch and a fraction above the surface of the table4 ,then1 with a pair of scissors1 cut out of a piece of tissue-paper a number of figures1 such as men1 women1 clowns1 frogs1 etc4 ,these little figures must not exceed three-quarters of an inch in length4 ,we show some of actual size in ,fig4 #a4 ,they may be cut out of papers of different colors1 so as to give variety to the scene4 ,after they are prepared they are to be placed in the ball-room1 that is to say1 in the space between the books1 glass1 and table4 ,they should be laid flat upon the table1 and alongside of one another4 ,now rub the upper surface of the glass vigorously with a piece of silk or woolen1 and1 in a few instants1 the figures will be attracted by the electricity1 and suddenly stand up straight and jump up to the transparent ceiling of their ball-room4 ,then they will be repelled1 and again attracted1 and thus keep up a lively dance4 ,when the rubbing is stopped1 the dance continues spontaneously for some little time1 and even the contact of the hand suffices to animate the figures4 ,in order that this experiment shall prove a success1 the glass used must be very dry1 as well as the fabric with which it is rubbed4 ,if the latter be warmed1 the manifestation will be more rapid and energetic4 ,silk answers better than woolen4 ,illustration3 ,,fig4 #b4--,,silhouette ,,portraits4 ,silhouette ,portraits4--,take a large sheet of paper1 black on one side and white on the other1 and affix it to the wall1 white surface outward1 by means of pins or tacks4 ,place a very bright light upon the table1 at a proper distance1 and allow the person whose portrait it is desired to form to stand between it and the wall 7,fig4 #b74 ,then1 with a pencil1 draw the outlines of the shadow projected4 ,while this is being done1 it is very necessary that the subject shall keep perfectly immovable4 ,when the outlines are sketched1 remove the paper from the wall and cut out the portrait4 ,after this1 all that remains to be done is to turn the portrait over and paste it to a sheet of white paper4 ,the silhouette is profiled in black1 and if the operation be skillfully performed1 the resemblance will be perfect4--,la ,nature4 99 99 99 99 99 ,,how ,,to ,,break ,a ,,cord ,,with ,,the ,,hands4 ,our readers have often seen grocers' clerks or employes of business houses break the string with which they had tied up a package1 by seizing it with the hands1 bringing the latter close together1 and then suddenly separating them with a quick movement4 ,if it be thought that this quick motion is sufficient1 let any one try it1 and he will merely cut his hands without breaking the string1 provided the latter has some little strength4 ,in order to succeed1 the cord must be arranged in a certain manner1 as we shall explain4 ,illustration3 ,,mode ,,of ,,breaking ,a ,,cord ,,with ,,the ,,hands4 ,the cord to be broken is placed upon the left hand1 and one of its ends is passed over the other in such a way as to form a cross1 and the end forming the shorter part of the cross is wound around the fingers 7it should be left long enough to make several turns74 ,the other end is then turned back and wound around the right hand1 so as to leave a space of about eighteen inches between the latter and the left hand4 ,if these directions are properly followed1 the string should have the form of a ,y in the middle of the hand1 as shown in the lower figure of the accompanying engraving4 ,it is only necessary after this to close the hand1 after seeing that the ,y is very taut1 and to seize the cord with the other hand1 as shown in the upper figure4 ,this done1 the two hands are brought together and then suddenly separated so as to give a quick pull on the point of junction of the ,y-shaped branches1 which form a true knife4 ,it will be readily seen that as the cord is broken suddenly the shock does not have time to transmit itself to the hands4 ,this is an interesting demonstration of the principle of inertia4 99 99 99 99 99 ,,an ,,aquatic ,,velocipede ,,for ,,duck ,,hunting4 ,the curious apparatus that we represent in ,fig4 #a1 from an old ,english engraving of #ahbc1 is an aquatic velocipede which was utilized with success during the entire winter of #ahbb4 ,an amateur employed it for hunting ducks upon the numerous streams of ,lincolnshire1 and1 as it appears1 obtained very good results from it4 ,the device is very ingenious4 ,it consists of three floats of from #a1hjj to #b1jjj cubic inches capacity1 made of copper or tin plate4 ,these are full of air1 and must be perfectly tight4 ,they are held together by arched iron rods1 as shown in the cut1 so as to form the three angles of an isosceles triangle4 ,these rods are provided in the center with a saddle for the velocipedist to sit upon4 ,the apparatus floats upon the water and sustains the hunter1 whose feet are provided with quite short paddles1 by means of which he navigates1 and steers himself4 ,illustration3 ,,fig4 #a4--;,,an ,,aquatic ,,velocipede ,,of #ahbb4 ,the amusing engraving of this velocipede1 which is mentioned under the name of the aquatic tripod1 puts us in mind of another document of the same kind that we have seen in the gallery of prints of the ,national ,library4 ,it is a naively drawn lithograph representing a trial of velocipedes in the ,luxembourg ,garden1 at ,paris1 in #ahah4 ,in ,fig4 #b we give a reduced copy of it4 ,it will be seen that in #ahah velocipedes were made of wood and were provided with two wheels--one in front1 and the other behind4 ,the propelling was done by alternately placing the feet on the ground4 ,illustration3 ,,fig4 #b4--;,a ,,trial ,,of ,,velocipedes ,,in #ahah4 99 99 99 99 99 ,a ,,sunshine ,,recorder4 ,the apparatus is of simple construction4 ,it consists of a glass sphere silvered inside and placed before the lens of a camera1 the axis of the instrument being placed parallel to the polar axis of the earth4 ,the whole arrangement will be readily understood by an inspection of ,fig4 #a4 ,the light from the sun is reflected from the globe1 and some of it1 passing through the lens1 forms an image on a piece of prepared paper within the camera4 ,in consequence of the rotation of the earth1 the image describes an arc of a circle on the paper1 and when the sun is obscured1 this arc is necessarily discontinuous4 ,the image is not a point1 but a line1 and in certain relative positions of the sphere1 lens1 and paper1 the line is radial and very thin1 so that the obscuration of the sun for only one minute is indicated by a weakening of the image4 ,illustration3 ,,fig4 #a4 ,in the actual apparatus the sphere is an ordinary round-bottomed flask about #ie mm4 in diameter1 and the lens a simple double convex lens of about #ij mm4 focal length4 ,the sensitive paper employed is the ordinary ferro-prussiate now so much used by engineers for copying tracings4 ,this was selected in consequence of the ease with which the impression is fixed1 for the paper merely requires to be washed in a stream of water for six minutes1 no chemicals being necessary4 ,when the paper is dry1 radial lines containing between them angles of #ae are drawn from the center of the circular impression1 and thus give the hour scale1 the time of apparent noon being of course given by a line passing through the plan of the meridian4 ,fig4 #b is a copy of the record of ,june #bg1 #ahhd2 in the morning the sun shone brightly1 toward noon clouds began to form1 and in the afternoon the sky was hazy4 ,the field in which the instrument is placed is surrounded by trees1 so the ends of the trace are cut off sharply by shadows4 ,illustration3 ,,fig4 #b4 ,with the alteration of declination of the sun1 the light entering the camera is reflected from different portions of the sphere1 and an alteration of the position of the focus results4 ,this may be corrected in three ways2 by moving 7#a7 the paper1 7#b7 the lens1 or 7#c7 the sphere4 ,in the present apparatus the first method has been adopted1 and now the camera is about twice as long as it was in ,june4 ,as a consequence1 the circular image is enlarged1 and the light therefore weakened1 and that at a time of year when it can least be spared4 ,if the focus is altered by moving the lens1 the winter circle is small and the summer circle is much larger4 ,this would perhaps be too much to the advantage of the winter sun4 ,if1 however1 the lens and paper are maintained at a constant distance1 and the sphere alone moved1 the circles are more nearly of the same diameter throughout the year1 the winter one still remaining the smallest4 ,this seems1 therefore1 to be the most advantageous arrangement1 and the one that will be adopted in future4 ,it may be possible also to find positions for the sphere1 lens1 and paper such that the intensity of the image is a true measure of the intensity of the sun's light2 at present1 however1 this has not been done1 the want of sunlight and the press of official work having prevented the carrying out of the necessary experiments4 ,a more sensitive paper might also be used with advantage1 and in observatories where photographic processes are carried on daily there would be no difficulty on this score1 but my principal object was to devise some economical instrument requiring only easy manipulation1 so that at a considerable number of places the instruments might be set up1 giving a more useful average of the duration of sunshine than can be obtained from only a few stations4 ,the instrument also gives a record when the sun is shining through light clouds2 in this case the image is somewhat blurred and naturally weakened1 and it may be difficult or impossible to employ any scale for measuring the intensity under such conditions1 but it must be remembered that1 even when the sun is shining in this imperfect manner1 it is really doing work on the vegetation of the earth1 and deserves to be recorded4 ,it may be well to say that the instrument is in no way protected4 ,some friends1 whose opinion ,i highly value1 urged me to patent it2 but as ,i strongly hold the view that the work of all students of science should be given freely to the world1 the apparatus was described at the ,physical ,society a few hours after the advice was given1 lest the greed of filthy lucre should1 on further deliberation1 cause me to act contrary to my principles4--,herbert ,mc,leod1 ,nature4 99 99 99 99 99 ,,skeleton ,,of ,a ,,bear ,,found ,,in ,a ,,cave ,,in ,,styria1 ,,austria4 ,in the limestone mountains of the ,austrian ,alpine countries1 numerous large caverns and caves are found1 some of which are several miles long4 ,they have been formed by the raising1 lowering1 and sliding of the layers of sand1 or washed out by the stream4 ,in one of these caverns near ,peggau1 in ,styria1 ,austria1 the skeleton of a bear 7,ursus ,spelaeus7 and the skull of another bear of the same kind were found1 both of which are shown in the annexed cut taken from the ,illustrirte ,zeitung1 the detached skull being placed on a board4 ,the place in which these bones were found had never been reached before1 as the skeleton was covered by a layer1 from four to six inches thick1 of stalagmites1 which in turn rested on a layer of pieces or chips of bones and carbonate of lime1 sand1 etc4 ,the bones of the skeleton were scattered over a space about eight square yards1 and it required several days' work to remove the layers from the bones by means of a mallet and chisel and to give the bones1 etc41 a presentable appearance4 ,illustration3 ,,skeleton ,,of ,a ,,bear ,,found ,,in ,a ,,cave ,,in ,,styria1 ,,austria4 ,the skull on the board is of especial interest on account of the beautiful crystals of calcareous spar1 which are from #a_/aj to #a_/d of an inch long1 and are formed on the inner sides of the skull4 ,the skull is #e-a_/b in4 wide between the fangs and #f-c_/e in4 wide at the forehead1 whereas the skull of the skeleton is only #c-i_/aj in4 wide at the fangs and #e-a_/aj in4 wide at the forehead4 ,the skull of the skeleton is #bb in4 long4 ,the small white object on the board supporting the detached skull represents the skull of an ordinary cat1 thus giving an idea of the enormous size of the bear's skull4 ,the skeleton is #i ft4 #h in4 high1 and is one of the largest and most complete that has been found4 99 99 99 99 99 ,,the ,,hardness ,,of ,,metals4 ,the ,german ,verein zur ,bedfrderung des ,gewerbefleisses offers the following1 among other prizes1 for essays on technical subjects3 ,one thousand marks 7#ej7 for a comparative examination of the various methods hitherto used for determination of the hardness of metals1 with an exposition of their sources of error and limits of accuracy4 ,it is stated1 as a reason for offering the prize1 that the methods for making the required tests are but yet little developed1 and that no thorough comparison has yet been made of the various methods4 ,the hardness of metals and alloys being a very important factor in several processes1 a really good method of determination is highly desirable4 ,three thousand marks 7#aej7 for the best essay on the resistance to pressure of iron work in buildings1 at increased temperatures4 ,it appears that after a certain fire in a manufactory at ,berlin1 the police authorities issued notices concerning the use of cast-iron columns in high buildings1 and that these notices encountered great opposition in many quarters1 as it was considered that neither practice nor theory had yet shown any proof that cast iron is less trustworthy than wrought iron in cases of fire4 99 99 99 99 99 ,a brilliant black varnish for iron1 stone1 or wood can be made by thoroughly incorporating ivory black with common shellac varnish4 ,the mixture should be laid on very thin4 ,but ordinary coal tar varnish will serve the same purpose in most cases quite as well1 and it is not nearly so expensive4 99 99 99 99 99 ,,steam ,,yachts4 ,although the racing of steam yachts as a recognized sport has not made the progress that was at one time expected1 yet the owner and crew of a crack vessel will take as much interest in her performance as those belonging to a sailing yacht1 and hate to be passed quite as badly4 ,in this way many informal matches come off1 and some of these are for considerable distances4 ,the ,field contains a notice of a run recently made from ,plymouth ,breakwater to ,gibraltar1 by the ,juno1 owned by ,mr4 ,frank ,millan1 and the ,queen of ,palmyra1 in which the former beat the latter by only five minutes4 ,the time occupied was four days twenty hours1 a fair1 though not extraordinary1 performance for vessels of this size4 ,the ,juno has always been considered a slow boat1 but has been much improved lately by new machinery1 which has been put in her by ,messrs4 ,day1 ,summers ,co4 ,her best performance on the run was #bce knots in #ba hours4 ,the ,marchesa1 ,mr4 ,c4,t4 ,kettlewell1 started from ,plymouth on the #bc;d of last ,december1 and made the run to ,gibraltar in four days seventeen hours2 while the ,amy1 starting on ,december #ab1 was four days thirteen hours from ,cowes to ,gibraltar4 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 ,caveats4 ,trade ,marks1 their costs1 and how procured4 ,address ,,munn ,,co41 #cfa ,broadway1 ,new ,york4 ,branch ,office1 cor4 ,f and #gth ,sts41 ,washington1 ,d4,c4