Volume 39 (1879) (446 pages)

September 13, 1879. ] N MINING AND SCIENTIFIC PRESS. 163 ayn? ey M ECHANICAL ‘PROGRESS. Water-Power Engines with Variable Stroke, A Scotch engincer, Mr. John Hustie, says that about 13 years ago his atteution was called to tho necessity for somo form uf hydraulic power being substituted for horses in hoisting at the various sugar stores in Greenock; and he then designed a hydraulic wiuch mounted on wheols, and arranged to bo connected by flexihle tubing with tho nearost water-main, 30 that onc winch would be sufficient for several stores. In making the necessary calculations connected with this design he was surprised to find that tho consumption of water was the same, whether a light or heavy weight was beiug raised; in fact, that as much water would bo uscd in lifting the chain alono as was required for the greatest weight to be lifted. While thinking over this mattcr it occurred to him that if tho stroke of tho piston could be varied hy sonic simple mechanical means, the dithiculty would be ovorcomo; but uo encouragement was giveu to the employment of hydraulic powor at the time, * the matter was laid aside until about threo yeara ago, whou the Greenock local authorities obtained an act of Parliament giviug power to abolish the hoisting in the strect by borses. As the employment of some form of hydraulic hoist thus became almost a ucceasity, bia attention was again given to the principle, not only witb a view to hoists, but for general purposcs. His first efforta wero dirccted to obtaiuing a vanable stroke of piston in a water engine. This was achicved in two ways; first, by means of avariablo crank-pin, and secondly by employing a link as in tho expansion gear of a atoam engiue. Both of these arrangementa fulfilled the conditions required, but the variable piu was sclected, as capable of being applied in & more compact form than the link. ‘The principle was developed in three forms: (1) an arraugement with a screw, similar to the crankpin of a slotting macbine, which enables tbo eugine to be set before starting so as to nse a given quautity of water for any given amount of work; (2) an arrangement for varying tbe radius of the pin by hand while the engine was at work, which was a much more rapid way of efforting tho change in the stroke than the formor; (3) an arrangement for making the variation of the stroke automatic, the amount of work to be done by the eugine being itself the means employed for effecting the change. This was by far the best method of the tbree. Engines on all these three principles have been constructed; 18 engines in all are now at work, and others are in course of construction. But the third or automatic method of varying tbe stroke is the most perfect form of tbis iuvention, and fulfills all the conditious necessary for the economical working of hydranlic motors witb variable loads. The consumption of water varies in proportiou to tho power required. A New Nour Macuive.—A new machine for sawing iron nuts has been invented in Springfield, Mass. The nut on which this macbine is designed to work is of ordinary iron, but witb two slots eut at right angles across the npper surface half as deep as the nut, so that when it ig turned tight upon tho nut the grip of the wrench closes up the apertures so much that it is impossible for the nut to work loose. The new machine will cut tbe slota in tbe red-hot iron as fast as it can be fed. The nuts are placed upon nn iron plate in front of the operator, who with one hand pusbes them forward till they drop one by one into an open box fitted to them, in which they are moved by gauge against a circular saw. A motion of the hand then turns each a quarter of the way round, when it is pushed against a second saw for the other slit. Tbus, after the first onc is cut into in one direction, two are slotted in the opposite direction by the same forward pressure against the saws. The saws, of soft steel, revolve 3,000 times a minute, the periphery traveling nearly four miles per minute, and the iron is sawed into as easily as a piece of wood on an ordinary maebine. The machine will easily slot a ton of nuts, avers ging 4,000 in number, in a day, and can probably be run up to a ton and a balf. Pressure Repucer.—In order to rslieve lowlying and branch maina, and domestic service pipes from excessive or unnecessary pressure, and thereby reducing tbe liahility to bursts in the former case, and of injury to house fittings in the latter, a reducer has lately been invented in Glasgow, the action of which is as follows: The valve is perfectly balanced, so far as the inlet pressure is concerned; hence, if there be no pressure in tbe outlet main, it falls from its seat by its own weight and allows the water to pass; but when the pressure on the outlet main becomes sufficient to lift the valve, it forces it back to its seat, where it will remain uutil the Pressure in the outlet is again reduced. All, therefore, that is nécessary in order to obtain a fixed limit of pressure in the delivery pipe is to weight the valve, either by dead weight or spring and lever, to such an extentas to balance the intended pressure when acting on the valve. When this bas been done, the pressure in the inlet may vary to any extent, but that in tbe outlet can never rise above the fixed limit, Tosourar Pires.—TheScientific American describes anovel and ingenions system of constructing and driving piles which has of late been introduced into practice by Messrs. Le Grand & Sutcliff, of London, artesian well ongineers, It involves a considerable departure from ordinary practice, inasmuch as the piles ars driven interually and at the bottom, instead of externally and at the top. The invention origiuated with the senior member of the firm, whilst the credit of souie of ths applicatious of the principle is due to ths junior member, ‘Tho piles, says Lngineering, are tubular, aud can be mado of either wrought or cast-iron, and the thickness of tho mstal can bo proportioned to suit the varyin circumstauces of construction. The lower en of the pile is nade solid and pointed, and is gouerally of wrought-iron and stecl-tipped. The piles are mado in ecetions, which are screwod togetber by stroug stcel sockets or joint covers, which are barrel-shaped on the outside in order to diminish friction when being drivon. The method of driving these piles is as simple asit isnovel, Instead of the blows being dolivered on the head of tho pile, the driving forco is expeuded just whero it is wanted, namely, at the point. This result is attained by naing au elougated cylindrical driving weight, which travels casily inside the tuhe. Tho weight is raised by moans of rope or roda, aud is allowed to fall on the flat head of the solid point, the pile thus forming its own guide for the driving weight. The effect of each blow is to drag rather than to drive the pile down. The point is swelled, and of sufficient diameter to effect a clearance for the joint covers, which have to follow it down. This pile fractures and passes through minor obstructions. Tbe system commenda itself for its simplicity. A VALUABLE IsyeNTION FoR THE LAUNDRY. A man in Bridgeport, Conn., bag invented a very simple but ingenious machine for ironing shirts, It consists of an iron framework about five feet long, three feet wide and two and onehalf bigh. On the top of tbe framework ia attached the iron, which is a hollow cylinder or roller, 16 inches long aud 18 inches in diameter. This is provided with arms at each end, and, being attached to a crank, when in motion it rides hack and forth on tbe framework. The cylinder is heated by gas. An attachment called the bosom board is connected at the end of the frame by hinges. The operator stands at the end of the frame and operates tbe machine very simply. The sbirt is placed over the board the same as when ironed by band, being drawn tight and smootb. The rd is then thrown down in its place with the bosom upward. The heated cylinder passes over and finishes the work, ‘This machine is capable of ironing from 500 to 600 shirts a day. Scraping Hoes py MacwineRy.—Man’s inventive genius descends on many occasions toa porcine level. This remark is called fortb by an inveotion used in Chicago in the packing houses of Armour & Co. for scraping hogs. As the scalded bogs pass over the revolving flukes they are scraped clean at the rate of ten hogs per minute, as we lately witnessed in company witb some prominent agricultural gentlemen from the South wbo had come here to: see the commercial emporium of tbe West, and tbe greatest live stock, grain and lumber mart of the world. And it is interesting to note tbe improvement which must have becn effected in this marvelous machinery during the past year or ao; for, if we remember rightly, the previous account of it was that large hogs could be scraped in ten seconds and amall ones almost momentarily. So that there bas been a saving of four seconds on big pigs, and posyibly a fraction of a second or so on amall ones. Great PRESSURE UPON PowvERED SuzsTANCES.—Mr. Spring, a member of the Belgian Academy of Science, has made several very interesting experiments on the above subject with the following results, as reported in tbe Chemiker Zeitung: In a hollow steel bar, the sides of which were 64-100 of an inch thick, he subjected sevcral powdered substancea to a pressure of 20,000 atmospberes (133 tons per square inch). Molten and powdered saltpeter was pressed into a solid bard mass like porcelain. Powdered poplar wood was pressed into a block of much greater hardness than that possessed by the wood itself. The specific weight of tbe powder was 0.389, and that of tbe compressed block, 1.328. A powdered grindstone was transformed into a new atone of tbe same hardness as tbe original one. The same waa the case witb cbalk. ImpRoveD Ruxrostat.—Tbia instrument, first invented by Sir Charles Wheatstone for putting a known resistance into a galvanic circuit and tbns regulating the current’a strength, has been improved by a gentleman in New York city. The bed plate is made of non-conducting material, and in an annular groove in its upper surface there is a film or plate of material that offers considerable resistance to tbe electrical current. Generally the groove is partly filled witb plumbago. One end of the resistant is connected witb a battery, and the current is completed through a movable key whose pivot ig at the center of the circular groove, The key is provided with a roller which“ rests upon the plumbago and movee over its surface without abrading it. This rbeostat seems especially adapted to tbe use of pbysicians and experimenters, Cw BCIENTIFIC Procress, Coal Tar Colors. The wonderful growth of the industries engaged in the production of alizarins (artificia’ madder) and the coal tar colors generally, is the subject of a paper lately read beforo the Cbemical Section of the London Socioty of Arts, by W. H. Perkius, F.R.S. The author, whose name is closely associated with the development of these mannfactures in England, places the valne of all the coal tar colors, pruluced in Enropo iu 1878 at $15,750,0uu, divided as follows : Germany....$16,000,000 France..... $1,750,000 England . .250,000 Switzerland.. 1,750,000 Tolal.. pecsicessaeewen sss $16,760,000 Germany has at present 17 coal tar color works, Iingland has six, France five, and Switzerland four ; besides which there are tlrce works in Germany and as many in Franco which manufacture anilino in enormous quantitics for the production of coal tar colors. Of alizarinc the total production is cstimated to be 9,500 tons, representing a money value of $7,225,000. Tho notewortby and instructive thing about this whole subject is the fact that these enornous industries, which have sprung into existenco since 1856, are entirely the fruits of theoretical researches in orgauic chemistry, and the extensive researches may be expected ere long to bear practical fruit, possibly even more valuable. Another subject toward whicb the eyes of chemists are turned witb expectation is the artificial production of indigo upon the commercial scale. The distinguished German cbemist, Beyer, has succeeded in putting out of the way tho chief difficulty by actually producing it in tbe laboratory. THe CHrRomooraPH.—Mr. Albert Ungerer, of Vienna, has discovered a process of copying letters, which requires no more delicacy of manipulation than the drying of a letter with an ordinary piece of blotting paper. It consists of a slab of gelatinous material having the appearance of soft vulcanized india rubber, contained in a zine tray. With this there is aupplied a small bottle of iuk—apparently an aniline compound—witb which tbe circular or drawing to be reproduced is written npon any ordinary piece of paper, and permitted to dry. The writing is then placed face downward on the composition, and the band is then passed lightly over it; after being left for a minute the paper is lifted, and every line and detail of the negative is found upon tbe composition witb absolute precision, ‘The reproduction can now be commenced; a sheet of ordinary paper is pressed upon the negative as in using blotting paper on a letter, and copies may be obtained consecutively to the number of 40 or 50. When the required number bas been obtained, the negative is wasbed off, and tbe apparatus is ready for fresb work. As tbe copies can be obtained in several colors at one operation, it will be obvious that the apparatus will be of immense value in engineers’ offices for reproducing sketches of macbinery for the guidance of intending purcbasers or manufacturers, and that it will be not less useful in mine and public companies’ offices for the reproduction of reports and balance sbeets for the information of, or to be revised by auditors or directors previous to printing them. As soon as known, the chromograph will certainly be almost universally adopted. Itis being extensively introduced in England by Mr. Otto Lelm, of Farringdon atreet, E. C., London. Fire Extincvisner.—Mr. Watson Smitb discovered, several years ago, thet crude ammonia water, or gas liquor, as it is called, acts like a charm in extinguishing a fire in a tar diatillery. He now recommends tbat owners of cotton mills, and of tar works, varnisb works, etc., should have on their premises a stock of about 1,000 gallons of tbis gas liquor stored ina tank or old boiler, mounted upon brick-work, and at such an altitude as to give pressure enough for a good jet service in case of fire. There is no reason why this cheap and efficient preventive of destructive conflagrations should not be generally adopted. It may be readily imagined, says Mr. Smith, bow a jet of tbe liquor, thrown into a burning room, would act, the space being 80 enclosed, when the action is so powerful in a comparatively open space, and with such a refractory snbstance as burning pitch. It would seem, he adds, that tbe extinguiabing power of the liquor would be even furtber calied fortb by a more intensely hot fire, for bere, in all propability, tbe ammonia would be decomposed, and tbe generated bydrogen and nitrogen gases would belp to swell tbe volume of non-snpportive gas, displacing the air, and so choking out the combustion. New Exprosrve.—Prof. Emerson Reynolds, of Dublin, bas discovered a new explosive, compounded of two substances, whicb can be kept apart without risk, and can be mixed as required to form a blasting agent. The powder is a mixture of 75 parts of chlorate of potassium witb 25 parts of “sulpburea,” a body discovered by Prof. Reynolds, wbhicb can be obtained cheaply from a waste product of gas manufacture. Tbe new explosive is a white powder, whicb can be ignited at a lower temperature tban gunpowder, and leaves less solid reeidue, Utitization or EXuausr STeam, —According to the invention of Mr. N. W. Ericson, of Stockholm, he lets steam of higher pressure, or higher temperature, or botb higher presgure and temperature than ths pressuro or temperature, or both, of the steam which is to bo nsed in a steam engine or for any otber purpose, pass into an epparatus for tho suction and coupression of elastic fluids, in order that the said higher or stronger steam may in such apparatus act as the suction fluid to the said spent steam; this suc. tion and compression apparatus is further connected with the apparatus wherein steam is to be used in order that the speut steam may toa greater or less extent be drawn into the suction and compression apparatus when the actiug or higher atean: passes throngh it. Tbe mixture of the actins ordrawiug steam aud the spent steam passes through the delivery pipe of the suction aud compression apparatus ane ita continuation, as required) either to the place where the thus compressed steam is to be used, or else firet through an apparatus coutainiug saturated steam or water, or in so near connection witb watcr that tho steam, if in a superheated atate, becomes more or leas saturated or lowered in temperature, or olse into an apparatus wherein the steam, by cooling, is rendered liquid, and the heat thereby given out is used for generation of fresh steam. ‘bis latter apparatus may be the steain boiler in which the acting supsrheated steam is generated, or another steam boiler vessel. The suction and compression apparatna may be any suitable suction and compression apparatus, such as nn annular or other jet apparatus. Drarer’s RESEARCHES ON OXYOEN IN THE Sun.—Prof. Henry Draper, on the 13tb of Juue, laid before the Royal Astronomical Society of London the evidence by which he claims to bave demonstrated the existence of oxygen in the sun, A writerin the London 'imes (presumably Mr. J. Norman Lockyer) acknowlodie the force of the evidence adduced by Prof, Draper, He saya: ‘We thiuk that mostspectroscopists will admit that Prof. Draper does not pass beyond the limits of scientific caution in claiming that tbe coincidence shown in bis photographs between tbe bright lines of oxygen and bright parts of the solar spectrum establisbes the probability of the existence of oxygen in the sun. The burden of proof, or rather of disproof, sbould now fall on those who consider that the coincidence may, after all, be merely accidental, To us it seema that if such evidence as Prof. Draper has obtained ia rejected, hardly any spectroscopic evidence can suffice to prove the existeuce of an element in the sun. We certainly bave not strongsr evidence in the case of sodium or magnesium, elementa wh‘cb every physicist regards as present in the snn, than Prof. Draper has obtained in the case of oxygen.” PHOTOGRAPH oF THE Oxycen SPECTRUM. — The spectrum sbowed the lines described by Paalzow, O between 6 and E, O close by F, and O between F and G. A band of great intensity, which the autbor names QO, lies nearh. It is sbarply defined toward the red end of the spectrum, but shades away toward the violet extremity. A double band, Os, near G, has the same character. In tbe spectrum of bydrogen the three already known bydrogen lines in the blue and voilet were seen very distinctly, and also the red line, Ha, coincident witb C of the sun. The fourtb hydrogen line, coinciding witb “kh” of tbe sun, waa observed with the naked eye by Paalzow and the author, on the application of the simple induction current, in opposition to the assertion of Lockver tbat it ia only visible at, very bigh temperatures. Upon tbis assertion he found in part bia supposition of tbe decomposition of hydrogen at elevated temperatures.— A, W. Vogel, in Scientific American. BREAKAGE oF Locomotive AXLEs.—For some time it was suspected by tbe officers of the Frankfort and Bebra railroad, Germauy, that the practice of casting white-metal bearings around steel axles bad been the primary cause of several breakages on tbe line, and a series of experiments were undertaken to ascertain the possibility of such being the case. By repeating the casting process a number of times “on the same axle, it was found that in every case, and with every kind of steel tried, cracks appeared sooner or later, sometimes on tbe second trial, sometimes not till the forty-fiftb. The white metal used contained 7 parts copper, 14 parts antimony, and 79 parts zine, and melted between 810° to 932° Fabr. These experiments, therefore, tended to sbow that tbe plan of caating white metal round tbe axle is a fruitful source of danger. New Lamp ror Passenger Cars.—The wellknown inventor, Geo, Westinghouse, bas devised a lamp for passenger cara, which he thinks will supersede the ordinary oil lamp. It haa been tried with satisfaction on tbe North British railway, Scotland, for some time. The use of the Westingbouse brake places at disposal a large amount of compressed air. When air is passed over benzine, or similar ligbt bydrocarbons, it becomes saturated with tbe hydrocarbon vapor, and may tben be burned just like ordinary illuminating gas. Beneath each car, therefore, 2 long cylinder is placed, which is filled with felt, eaturated with petroleum. A current of compressed air, entering the cylinder at one end and escaping at tbe other, is led up to the roof of the car and burned in lamps of very elegant construction.

September 13, 1879. ] N MINING AND SCIENTIFIC PRESS. 163 ayn? ey M ECHANICAL ‘PROGRESS. Water-Power Engines with Variable Stroke, A Scotch engincer, Mr. John Hustie, says that about 13 years ago his atteution was called to tho necessity for somo form uf hydraulic power being substituted for horses in hoisting at the various sugar stores in Greenock; and he then designed a hydraulic wiuch mounted on wheols, and arranged to bo connected by flexihle tubing with tho nearost water-main, 30 that onc winch would be sufficient for several stores. In making the necessary calculations connected with this design he was surprised to find that tho consumption of water was the same, whether a light or heavy weight was beiug raised; in fact, that as much water would bo uscd in lifting the chain alono as was required for the greatest weight to be lifted. While thinking over this mattcr it occurred to him that if tho stroke of tho piston could be varied hy sonic simple mechanical means, the dithiculty would be ovorcomo; but uo encouragement was giveu to the employment of hydraulic powor at the time, * the matter was laid aside until about threo yeara ago, whou the Greenock local authorities obtained an act of Parliament giviug power to abolish the hoisting in the strect by borses. As the employment of some form of hydraulic hoist thus became almost a ucceasity, bia attention was again given to the principle, not only witb a view to hoists, but for general purposcs. His first efforta wero dirccted to obtaiuing a vanable stroke of piston in a water engine. This was achicved in two ways; first, by means of avariablo crank-pin, and secondly by employing a link as in tho expansion gear of a atoam engiue. Both of these arrangementa fulfilled the conditions required, but the variable piu was sclected, as capable of being applied in & more compact form than the link. ‘The principle was developed in three forms: (1) an arraugement with a screw, similar to the crankpin of a slotting macbine, which enables tbo eugine to be set before starting so as to nse a given quautity of water for any given amount of work; (2) an arrangement for varying tbe radius of the pin by hand while the engine was at work, which was a much more rapid way of efforting tho change in the stroke than the formor; (3) an arrangement for making the variation of the stroke automatic, the amount of work to be done by the eugine being itself the means employed for effecting the change. This was by far the best method of the tbree. Engines on all these three principles have been constructed; 18 engines in all are now at work, and others are in course of construction. But the third or automatic method of varying tbe stroke is the most perfect form of tbis iuvention, and fulfills all the conditious necessary for the economical working of hydranlic motors witb variable loads. The consumption of water varies in proportiou to tho power required. A New Nour Macuive.—A new machine for sawing iron nuts has been invented in Springfield, Mass. The nut on which this macbine is designed to work is of ordinary iron, but witb two slots eut at right angles across the npper surface half as deep as the nut, so that when it ig turned tight upon tho nut the grip of the wrench closes up the apertures so much that it is impossible for the nut to work loose. The new machine will cut tbe slota in tbe red-hot iron as fast as it can be fed. The nuts are placed upon nn iron plate in front of the operator, who with one hand pusbes them forward till they drop one by one into an open box fitted to them, in which they are moved by gauge against a circular saw. A motion of the hand then turns each a quarter of the way round, when it is pushed against a second saw for the other slit. Tbus, after the first onc is cut into in one direction, two are slotted in the opposite direction by the same forward pressure against the saws. The saws, of soft steel, revolve 3,000 times a minute, the periphery traveling nearly four miles per minute, and the iron is sawed into as easily as a piece of wood on an ordinary maebine. The machine will easily slot a ton of nuts, avers ging 4,000 in number, in a day, and can probably be run up to a ton and a balf. Pressure Repucer.—In order to rslieve lowlying and branch maina, and domestic service pipes from excessive or unnecessary pressure, and thereby reducing tbe liahility to bursts in the former case, and of injury to house fittings in the latter, a reducer has lately been invented in Glasgow, the action of which is as follows: The valve is perfectly balanced, so far as the inlet pressure is concerned; hence, if there be no pressure in tbe outlet main, it falls from its seat by its own weight and allows the water to pass; but when the pressure on the outlet main becomes sufficient to lift the valve, it forces it back to its seat, where it will remain uutil the Pressure in the outlet is again reduced. All, therefore, that is nécessary in order to obtain a fixed limit of pressure in the delivery pipe is to weight the valve, either by dead weight or spring and lever, to such an extentas to balance the intended pressure when acting on the valve. When this bas been done, the pressure in the inlet may vary to any extent, but that in tbe outlet can never rise above the fixed limit, Tosourar Pires.—TheScientific American describes anovel and ingenions system of constructing and driving piles which has of late been introduced into practice by Messrs. Le Grand & Sutcliff, of London, artesian well ongineers, It involves a considerable departure from ordinary practice, inasmuch as the piles ars driven interually and at the bottom, instead of externally and at the top. The invention origiuated with the senior member of the firm, whilst the credit of souie of ths applicatious of the principle is due to ths junior member, ‘Tho piles, says Lngineering, are tubular, aud can be mado of either wrought or cast-iron, and the thickness of tho mstal can bo proportioned to suit the varyin circumstauces of construction. The lower en of the pile is nade solid and pointed, and is gouerally of wrought-iron and stecl-tipped. The piles are mado in ecetions, which are screwod togetber by stroug stcel sockets or joint covers, which are barrel-shaped on the outside in order to diminish friction when being drivon. The method of driving these piles is as simple asit isnovel, Instead of the blows being dolivered on the head of tho pile, the driving forco is expeuded just whero it is wanted, namely, at the point. This result is attained by naing au elougated cylindrical driving weight, which travels casily inside the tuhe. Tho weight is raised by moans of rope or roda, aud is allowed to fall on the flat head of the solid point, the pile thus forming its own guide for the driving weight. The effect of each blow is to drag rather than to drive the pile down. The point is swelled, and of sufficient diameter to effect a clearance for the joint covers, which have to follow it down. This pile fractures and passes through minor obstructions. Tbe system commenda itself for its simplicity. A VALUABLE IsyeNTION FoR THE LAUNDRY. A man in Bridgeport, Conn., bag invented a very simple but ingenious machine for ironing shirts, It consists of an iron framework about five feet long, three feet wide and two and onehalf bigh. On the top of tbe framework ia attached the iron, which is a hollow cylinder or roller, 16 inches long aud 18 inches in diameter. This is provided with arms at each end, and, being attached to a crank, when in motion it rides hack and forth on tbe framework. The cylinder is heated by gas. An attachment called the bosom board is connected at the end of the frame by hinges. The operator stands at the end of the frame and operates tbe machine very simply. The sbirt is placed over the board the same as when ironed by band, being drawn tight and smootb. The rd is then thrown down in its place with the bosom upward. The heated cylinder passes over and finishes the work, ‘This machine is capable of ironing from 500 to 600 shirts a day. Scraping Hoes py MacwineRy.—Man’s inventive genius descends on many occasions toa porcine level. This remark is called fortb by an inveotion used in Chicago in the packing houses of Armour & Co. for scraping hogs. As the scalded bogs pass over the revolving flukes they are scraped clean at the rate of ten hogs per minute, as we lately witnessed in company witb some prominent agricultural gentlemen from the South wbo had come here to: see the commercial emporium of tbe West, and tbe greatest live stock, grain and lumber mart of the world. And it is interesting to note tbe improvement which must have becn effected in this marvelous machinery during the past year or ao; for, if we remember rightly, the previous account of it was that large hogs could be scraped in ten seconds and amall ones almost momentarily. So that there bas been a saving of four seconds on big pigs, and posyibly a fraction of a second or so on amall ones. Great PRESSURE UPON PowvERED SuzsTANCES.—Mr. Spring, a member of the Belgian Academy of Science, has made several very interesting experiments on the above subject with the following results, as reported in tbe Chemiker Zeitung: In a hollow steel bar, the sides of which were 64-100 of an inch thick, he subjected sevcral powdered substancea to a pressure of 20,000 atmospberes (133 tons per square inch). Molten and powdered saltpeter was pressed into a solid bard mass like porcelain. Powdered poplar wood was pressed into a block of much greater hardness than that possessed by the wood itself. The specific weight of tbe powder was 0.389, and that of tbe compressed block, 1.328. A powdered grindstone was transformed into a new atone of tbe same hardness as tbe original one. The same waa the case witb cbalk. ImpRoveD Ruxrostat.—Tbia instrument, first invented by Sir Charles Wheatstone for putting a known resistance into a galvanic circuit and tbns regulating the current’a strength, has been improved by a gentleman in New York city. The bed plate is made of non-conducting material, and in an annular groove in its upper surface there is a film or plate of material that offers considerable resistance to tbe electrical current. Generally the groove is partly filled witb plumbago. One end of the resistant is connected witb a battery, and the current is completed through a movable key whose pivot ig at the center of the circular groove, The

key is provided with a roller which“ rests upon the plumbago and movee over its surface without abrading it. This rbeostat seems especially adapted to tbe use of pbysicians and experimenters, Cw BCIENTIFIC Procress, Coal Tar Colors. The wonderful growth of the industries engaged in the production of alizarins (artificia’ madder) and the coal tar colors generally, is the subject of a paper lately read beforo the Cbemical Section of the London Socioty of Arts, by W. H. Perkius, F.R.S. The author, whose name is closely associated with the development of these mannfactures in England, places the valne of all the coal tar colors, pruluced in Enropo iu 1878 at $15,750,0uu, divided as follows : Germany........$16,000,000 France.......... $1,750,000 England . .250,000 Switzerland... 1,750,000 Tolal... pecsicessaeewen sss $16,760,000 Germany has at present 17 coal tar color works, Iingland has six, France five, and Switzerland four ; besides which there are tlrce works in Germany and as many in Franco which manufacture anilino in enormous quantitics for the production of coal tar colors. Of alizarinc the total production is cstimated to be 9,500 tons, representing a money value of $7,225,000. Tho notewortby and instructive thing about this whole subject is the fact that these enornous industries, which have sprung into existenco since 1856, are entirely the fruits of theoretical researches in orgauic chemistry, and the extensive researches may be expected ere long to bear practical fruit, possibly even more valuable. Another subject toward whicb the eyes of chemists are turned witb expectation is the artificial production of indigo upon the commercial scale. The distinguished German cbemist, Beyer, has succeeded in putting out of the way tho chief difficulty by actually producing it in tbe laboratory. THe CHrRomooraPH.—Mr. Albert Ungerer, of Vienna, has discovered a process of copying letters, which requires no more delicacy of manipulation than the drying of a letter with an ordinary piece of blotting paper. It consists of a slab of gelatinous material having the appearance of soft vulcanized india rubber, contained in a zine tray. With this there is aupplied a small bottle of iuk—apparently an aniline compound—witb which tbe circular or drawing to be reproduced is written npon any ordinary piece of paper, and permitted to dry. The writing is then placed face downward on the composition, and the band is then passed lightly over it; after being left for a minute the paper is lifted, and every line and detail of the negative is found upon tbe composition witb absolute precision, ‘The reproduction can now be commenced; a sheet of ordinary paper is pressed upon the negative as in using blotting paper on a letter, and copies may be obtained consecutively to the number of 40 or 50. When the required number bas been obtained, the negative is wasbed off, and tbe apparatus is ready for fresb work. As tbe copies can be obtained in several colors at one operation, it will be obvious that the apparatus will be of immense value in engineers’ offices for reproducing sketches of macbinery for the guidance of intending purcbasers or manufacturers, and that it will be not less useful in mine and public companies’ offices for the reproduction of reports and balance sbeets for the information of, or to be revised by auditors or directors previous to printing them. As soon as known, the chromograph will certainly be almost universally adopted. Itis being extensively introduced in England by Mr. Otto Lelm, of Farringdon atreet, E. C., London. Fire Extincvisner.—Mr. Watson Smitb discovered, several years ago, thet crude ammonia water, or gas liquor, as it is called, acts like a charm in extinguishing a fire in a tar diatillery. He now recommends tbat owners of cotton mills, and of tar works, varnisb works, etc., should have on their premises a stock of about 1,000 gallons of tbis gas liquor stored ina tank or old boiler, mounted upon brick-work, and at such an altitude as to give pressure enough for a good jet service in case of fire. There is no reason why this cheap and efficient preventive of destructive conflagrations should not be generally adopted. It may be readily imagined, says Mr. Smith, bow a jet of tbe liquor, thrown into a burning room, would act, the space being 80 enclosed, when the action is so powerful in a comparatively open space, and with such a refractory snbstance as burning pitch. It would seem, he adds, that tbe extinguiabing power of the liquor would be even furtber calied fortb by a more intensely hot fire, for bere, in all propability, tbe ammonia would be decomposed, and tbe generated bydrogen and nitrogen gases would belp to swell tbe volume of non-snpportive gas, displacing the air, and so choking out the combustion. New Exprosrve.—Prof. Emerson Reynolds, of Dublin, bas discovered a new explosive, compounded of two substances, whicb can be kept apart without risk, and can be mixed as required to form a blasting agent. The powder is a mixture of 75 parts of chlorate of potassium witb 25 parts of “sulpburea,” a body discovered by Prof. Reynolds, wbhicb can be obtained cheaply from a waste product of gas manufacture. Tbe new explosive is a white powder, whicb can be ignited at a lower temperature tban gunpowder, and leaves less solid reeidue, Utitization or EXuausr STeam, —According to the invention of Mr. N. W. Ericson, of Stockholm, he lets steam of higher pressure, or higher temperature, or botb higher presgure and temperature than ths pressuro or temperature, or both, of the steam which is to bo nsed in a steam engine or for any otber purpose, pass into an epparatus for tho suction and coupression of elastic fluids, in order that the said higher or stronger steam may in such apparatus act as the suction fluid to the said spent steam; this suc. tion and compression apparatus is further connected with the apparatus wherein steam is to be used in order that the speut steam may toa greater or less extent be drawn into the suction and compression apparatus when the actiug or higher atean: passes throngh it. Tbe mixture of the actins ordrawiug steam aud the spent steam passes through the delivery pipe of the suction aud compression apparatus ane ita continuation, as required) either to the place where the thus compressed steam is to be used, or else firet through an apparatus coutainiug saturated steam or water, or in so near connection witb watcr that tho steam, if in a superheated atate, becomes more or leas saturated or lowered in temperature, or olse into an apparatus wherein the steam, by cooling, is rendered liquid, and the heat thereby given out is used for generation of fresh steam. ‘bis latter apparatus may be the steain boiler in which the acting supsrheated steam is generated, or another steam boiler vessel. The suction and compression apparatna may be any suitable suction and compression apparatus, such as nn annular or other jet apparatus. Drarer’s RESEARCHES ON OXYOEN IN THE Sun.—Prof. Henry Draper, on the 13tb of Juue, laid before the Royal Astronomical Society of London the evidence by which he claims to bave demonstrated the existence of oxygen in the sun, A writerin the London 'imes (presumably Mr. J. Norman Lockyer) acknowlodie the force of the evidence adduced by Prof, Draper, He saya: ‘We thiuk that mostspectroscopists will admit that Prof. Draper does not pass beyond the limits of scientific caution in claiming that tbe coincidence shown in bis photographs between tbe bright lines of oxygen and bright parts of the solar spectrum establisbes the probability of the existence of oxygen in the sun. The burden of proof, or rather of disproof, sbould now fall on those who consider that the coincidence may, after all, be merely accidental, To us it seema that if such evidence as Prof. Draper has obtained ia rejected, hardly any spectroscopic evidence can suffice to prove the existeuce of an element in the sun. We certainly bave not strongsr evidence in the case of sodium or magnesium, elementa wh‘cb every physicist regards as present in the snn, than Prof. Draper has obtained in the case of oxygen.” PHOTOGRAPH oF THE Oxycen SPECTRUM. — The spectrum sbowed the lines described by Paalzow, O between 6 and E, O close by F, and O between F and G. A band of great intensity, which the autbor names QO, lies nearh. It is sbarply defined toward the red end of the spectrum, but shades away toward the violet extremity. A double band, Os, near G, has the same character. In tbe spectrum of bydrogen the three already known bydrogen lines in the blue and voilet were seen very distinctly, and also the red line, Ha, coincident witb C of the sun. The fourtb hydrogen line, coinciding witb “kh” of tbe sun, waa observed with the naked eye by Paalzow and the author, on the application of the simple induction current, in opposition to the assertion of Lockver tbat it ia only visible at, very bigh temperatures. Upon tbis assertion he found in part bia supposition of tbe decomposition of hydrogen at elevated temperatures.— A, W. Vogel, in Scientific American. BREAKAGE oF Locomotive AXLEs.—For some time it was suspected by tbe officers of the Frankfort and Bebra railroad, Germauy, that the practice of casting white-metal bearings around steel axles bad been the primary cause of several breakages on tbe line, and a series of experiments were undertaken to ascertain the possibility of such being the case. By repeating the casting process a number of times “on the same axle, it was found that in every case, and with every kind of steel tried, cracks appeared sooner or later, sometimes on tbe second trial, sometimes not till the forty-fiftb. The white metal used contained 7 parts copper, 14 parts antimony, and 79 parts zine, and melted between 810° to 932° Fabr. These experiments, therefore, tended to sbow that tbe plan of caating white metal round tbe axle is a fruitful source of danger. New Lamp ror Passenger Cars.—The wellknown inventor, Geo, Westinghouse, bas devised a lamp for passenger cara, which he thinks will supersede the ordinary oil lamp. It haa been tried with satisfaction on tbe North British railway, Scotland, for some time. The use of the Westingbouse brake places at disposal a large amount of compressed air. When air is passed over benzine, or similar ligbt bydrocarbons, it becomes saturated with tbe hydrocarbon vapor, and may tben be burned just like ordinary illuminating gas. Beneath each car, therefore, 2 long cylinder is placed, which is filled with felt, eaturated with petroleum. A current of compressed air, entering the cylinder at one end and escaping at tbe other, is led up to the roof of the car and burned in lamps of very elegant construction.