Volume 28 (1874) (430 pages)

January 3. 1874-] MINING AND SCIENTIFIC PRESS. §clentiFic ®Procress. iron in Plants and Animals. Every one is familiar with the important part that lron playa in the work-ehops of man, but few are aware of the eqnally important part that it takes in the nperations of natnre—how it answers the same pnrpose in the miunte cells of which all animal nud vegetahle growth is made, as the tools in the hands of the skillful worker. For, so far as onr investigations have shown, Iron forms no essential part cf the plant or anlmal, yet withont lt all growth and assimilation ceise. If sceds are pluced on a little cotton wool in a solution containing all that is essential to plant growth, with tbe oxeeption nf iron, thoy will sprout and grow nntil the lron contained in the sacc itself is exhausted; tbo plaat then qnlokly bleaches aad ocases to grow. If a litthe phosphate of iron, which is almost totally icnalubile: iz added to the solution, and occasionally stirred np so that it may be keptin suspension and thn3 come in contact with the roots, tbn plant quickly revives and continues ita growth. Iron is an essential constitaent of chlorophyl, the groen coloring matter of leaves. Chlorophyl may he aoparated into at least two distinct ies, one green and the other hlue. Professor Horsford is of the opinion that this blne anhbstanco ia vivianite, or phosphate of iron. and gives the following experiment in support of this opinion: He mada a mixture of pbosphata of soda and protosnIphata of iroa, and found that this mixture was capable nf redncing carbonio acid to carbonic oxide, and that crystals of vivianite were formed in the operation. He therefore considers it probable that the formation of phosphato or protoxide of iron may ba a preliminary stage in the prodnotion of vegetahle tissne. There 1s also a well-known native phosphate of iron that is colorless when first mined, hnt on erposnra to light it becomes a beautifal blne. The amoant of iron existing in plants is extremely small. Bonssingaultfonnd that it was more abnndant in the oat thaa any other plant examined; hat thia contained only 131 parts in 1,000,000, while the white part of eabbaye coutained hnt nine parts, tha green ooutaining thirty-nine. Itelso abonnds in plants that are almost perfectly colorless; thus mushrooms contain twalve parts. Although found in all plants, and constitating an essential part of their food, it has never been thonght neoessary to supply it to them artifioally, all soils being snpposed to contain aufficient for their wants. Bnt no one oan have falled to observe the greater Inruriance of vegetation on the strong iron soils derived from the old red sandstone than on those granite soils which are comparatively free from it. It was long supposed that the red color of the blood was owing to the iron contained in it, but Malder and Vau Gnodoever fonnd that they ooald extraot the iroucompletely from the red coloring matter withont ‘destroying it. Moreover, the blood of an oyster also contains iron, althongh it is perfectly colorless. The want of iron in the system constitntes a disease which is well known to physicians nnder the name of chlorosia, and many remedies have been proposed for it. This want mnst generally arise from a defeotive state of the organs of assimilation; therefore it will be of little benefit to administer iron aloue, without adding to it dome other stimulating tonio, Varions preparations of this kind have from time to time been offered, and among these the various comhinations of iron and quinine have long held @ prominent place. These componnds should nll contain more or less of the metal in the form of protoxide, as the protoxide seems to be much more readily absorbed than the higher oxide; and they shonld be free from the well kuown inky taste generally possessed hy all compounds containing iron, The dose of ironshonld he small, and its use oontinued for some time. The amonnt which is necessary for a healthy man, and whioh he ohtains from his food, is from .9 to 1.5 grains per day, and it is probable that the dose should not greatly exceed this amonnt.—Journal of Chemistry. Smicon Srezu.—Mr. Calvin Pepper, au American experimentalist, claims to prodnce a true silicon steel by imhedding wronght iron bars in sand aud snhjecting them to a very high temperature, which canses the metal to part with its carhon inthe form of carbonic oxide, and to take up silicon from the sand, thus oonverting it into silicon steel. The Iron Age remarks on the snbject: '* This, at least, is what we understand to he his claim, aud as he asserts that he has accomplished what he claims, producing a true silioon steel by this method from wrought iron, we are not disposed to qnarrel with his theory untilwe have had opportunity of examining his prooess and testing the metal prodnced."" rs In 1867 M. Rabnteau announced that the poisonous power of the metals was greater as their atomic weights were higher and their epecifio heats were lower. This he now substantiates by additional discoveries, among them the toxic relation of potassium and calcinm, Iz is said that wheu alcohol is taken inter. nally, the temperature of the body siuks. With small quantities this lowering of temperature is 0,6° and somewhat more; in drunkenness a lowering of 2° has been noticed, The Behavior of Metais under Stress. Interesting and important resulta have been nbtaincd in the conrse of ths investigations iu progress at the Stevens Institnte of Technology npon the behavionr nf metals nnder stress, The testing machine invented and designed by Professor Thurston, with his antomatio rogistry, was descrihed in onr issne nf April last, and its pecniiar valae in detecting all phenomena of stress, and in affording a reliahlo and permauent record, ls shown by inspection of the curves giving in tbe plate accompanying that article. The apparatus was exhibited at the last mecting of the National Academy of Science, which was held at the Steveas Iastitnte, and its oapability of revealing tho aotion of moleenlar forces under stress was linstrated. At tha closo of the session a test piece was left in the machine, strainod far heyond its limit of elasticity, to determine, if possible, the existence or non-existence of “visoosity’’ in the metals. After twenty-fonr honrs, there appearing no evidence of further yielding, tha distorting foree was inoreased, when the discovery was made that the resisting power of the specimen had netnally become greater during the period of rest under strain, and the penoil, instead of doscending, rose nntil it indicated an increase of ahont twenty per cent. ia the strength nf tba sample, and it then traced a path parallel with but above that of the previons day. Repeated experiments confirmed this remarkable and important deduction of the experimenter: That metal strained so far as to take a permanent set, and left under the atress prodnducing it, gaina in power of resistance np to 8 limit of time, which in those experiments was abont seventy-two honrs, and to a limit of inorease whioh has a value, in the best iron, of abont 20 per oent., where the applied force is eighty per cent. of the nltimite breaking force. In other words, the metal develops nearly or quite its maximnm strength long before reaching the poiut of rnptnre, instead of at that point, 2s when brokeu at once by 2 continually increasing streas. This discovery was annonnced by Professor Thurston at the annaal meeting of the American Sooiety of Civil Engineers, November 5th, and the possible bearing of the earlier experiments of the Committee of the Franklin Institate on ‘’'Thermo-Tension,"’ and of the wellknown property of the inoreasing portative force of magaets under atrain, as illnstrations of related phenomena, were alluded to. The existence of this property had already been anspected, bnt itis evident that it could only be conclusively proven by apparatus embodying the principles of that used iu this research.— Journal of the Franiclin Institute. New Meruop or Enoravive.—J. Lnther Ringwalt, of Philadelphia, patented, in July, a new method of engraving typographic plates, or pictures, on zine, which he has successfully applied to the prodnction of book and newspaper illustrations, ornamental lettering, miscellaneons job work, show oards, etc., varying in size and fineness from small vignettes to half-sheet posters. He recently gave a detailed description of his process at a meeting of the Franklin Institate, on which occasion he had drawn and engraved, in thirty minntes, on a prepared plate, a portrait of Dr. Franklin, of nearly life size. Under his system, a zine plate is covered with a varnish capable of resistiag the action of the acid, through which a series of lines are drawn by a ruling machine at snch intervals as are required by the general character of the pictnre to be produced, thus Opehing up avenues iu which the acid can make the desired incisions; the shape, thickness, position and direction of these lines or scorings heing readily varied to suit different classes of work. The artist then draws npou this surface the desired design, creating additional blacks by applying a protecting liquid with a pen or brush at the points where additional blacks are reqnired, and removing the original groand, with an etching point or scrapcr, from the places where additional whites are necessary. This operation involves but little more labor than the prodnetion of a drawing on paper, and the character of the engraviag depends npon the degree of skill with which it is performed. The plate is next snbjected tothe action of the dilute acid, and at this stage a variety of tints can be prodnced by etching some portions of the work deeper and widar thau otbers. The process is so simple and inexpensive that it could readily be applied in any printing office which cau command art assistance.—Newspaper Reporter. Suoxe Consummd.—Some interesting experiments were lately made in Ohio, with a view to ascertaiuing the best method of consnming the smoke of soft coal furuaces, and, after a earefnl examination and test of a nnmher of mechanical appliances desigued to effect this object, the conclusion was reached that nothing was so simple and effective in preventing the escape of smoke as the introduction of sufficient oxygen into the furnace to effect complete comhustiou of the fuel, aud thns prevent the formation of any smoke at all, __A New Exprostve.— Ozobenzin is the name given by MM. Houzeau and Renard to a new explosive sabstance. It is produced by aoting npou benzin, boiling at 81° cent., with oncentrated ozone; formic and acetic acid are prodnced, and a gelatiuons precipitato formed, which, being dried in vacuo, becomes a white solid, which is the explosive compound named. It detonates violently when struck or when simply heated. It is unstable in the air; water decomposes and dissolves it. Ni ECHANICAL B roGRESS Small Motor Machines in Europe. The demand for an economical and convenient small motive power is felt and appreoiated throughont the civilized world. In this conntry we havo several patented inventions in this field, ntilizing steam, hot-air, gas and water, as the means of gencrating or conveying the force. We have also devices for storing np force where vory small power is reqnired, as for sewing-maohines, eome storing the powcr ina wonnd-up spring, a weight, in compressed air, or inn vacnum oylinder. Of the principal devices for small motive power in Europe, and exhihited at the Vienna Expositlon, may bo mentioned the following: Messrs. Otto & Laagen, in Gormany, and M. Lenoir, in France, niake 8 machine which is driven by the explosive force of lightiag gaa; Mr. W. Lehman, in Germany, constrnots n hotsir machine which claims to benn improvement npon the idea of our American engineer, Capt, Ericsson; whilo M. Hermon La Chapelle, in Paris, and others more conservative, bnild diminntive steam-engiaes. The gas-engine of M. Lenoir in external appearance resembles a horizontal steam-engine, and indeed is nearly the snme internally, having the same parts, piston, oylinder, valves, eto., but the power is ohtained hy exploding a mixtore of gas and atmospherio sir in the eylinder. During the first half of each stroke the piston sncks into the cylinder air and gas in the right proportions. At the half stroke the mixture is exploded by an electrio spark, whioh forces the piston throngh the remainder of the stroke, Messrs. Otto & Langen's machine consists of an upright cylinder, open at the top, in which plays vertically a piston having a ratcheted rod, so arranged asin the down stroke to engage a cog-wheel, attached to the arzle of the fly-wheel of the machine. The piston, during a amall portion of its upward course, takes in the rightly-proppnign qd mixture of gas and air, which is exploded at the point of the piston’s course, where the mixtnreis shut off. Explosion of the mixture carries the piston upward until the pressnre of the external atmosphere stops it. The explosion, depending upon expansion of gases by heat at the instant of combination, is immediately followed by a condensation and partial yaounm in the cylinder. The pressure of the atmosphere npon the pistou forces it downward, and the ratcheted rod, engaging the cog-wheel, imparts this force to the fly-wheel. Itis claimed for this machine that it is much more economical of gas thau M. Leuoir's. The complications incident to the ratchet and cogwheel arrangement are ohjectiouable; bnt it is spoken of as having qnitean extended nse. he cousnmption of gas is abont a cubic meter (39.31 cubic feet) per horse-power per honr, With gaa at $3.50 per thonsand this would give nine-six cents per day per horse-power. Of the small water motors, that of Mr. Schmid, in Zurioh, a small oscillating water engine is well spoken of. It is on ahont the same principle as the oscillating stenm-engine ; having, of conrse, mnch larger valve-ports. It hardly need be remarked that the water-engine can only be used where a small supply of water with considerable head is at hand, aais the case in cities where the cost of water is not too great. In Zurich, where the water is snpplied by a pump, worked by eighty horse power, the Schmid engine has come qnite extensively into nse. The water column motor of Mayer, in Vienna, also designed for light work, is iu prinoiple like a horizoutal steam-engine. The arrangement of the regulator and air-cnshion, for the pnrpose of avoiding the hydraulic shock incident to snch engines, is quite ingenious. The machine requires more space than that of Schmid’s, The emall turbine wheels of Messrs, Escher & Wyss, and of Mr. Gwynne, are also designed for the utilization of power furnished by a water column ona small scale. The hot-air machine of Lehman claims to have an advantage over the Ericsson engine in an arrangement by which the air in immediate contact with the piston is never heated ahove 30° Cent. (86° Fahr.), thus saving the packing and lubricating materia! of the piston. Beyoud this advantage it is not easy to see the superiority. + ‘Then oome the small steam-eugiues of M. Herman La, Chapelle, in Paris, which have nothing remarkahle about them, except that they are small and well made. It is very questiorable whether, when people come to learn that small steam-engines can be made perfectly safe, and can be rnu withont any extraordiuary skill or judgmeut, the advantages of all the so-called improved motors willseem so great as at present. For most cares where small motive power is needed, the small steam-engine, if well devised, and well made, is the cheapest and the best.— Artisan. Ir is stated that the quantity of coal necessary to raise a million gallons of water 100 feet, varies iu England from 17 ewt. to 114 cwt.; this is said to be due to the varying qualities of coal nsed, but more particularly to the construction of the pumping engines. Two monitors are being constructedat Bremen for use on the Rhine. They are covered with a one iuch plating—a sufficient protection agaiust infantry fire, and, it is thought, egaiust field artillery. They will draw only five feet of water. Sand Blast Engraving. The British Trade Journal seems pleased with Tilghman’s contrivance for engraving on glass, by means nf sand blast. It is a Phila: delphia invention, lately on exhibition at tha London International Exhibition. The principle of the apparatus is by a blast of air, steam, &c., to canse innumerable particles of sand to impinge where portions of glase, stone, metal, &o., are to be removed. Mr. Tilghman is thus enabled to produce not only excellent work, but with a rapidity almost incredible. For example, a sqnare or triangniar hole of half an inch in the side can ba bored throngha sheet of ordinary plate window glass in less than one minute. Designs of lace work—also photographs—can be ‘’eroded’’ or '‘gronnd’’ on glass with great rapidity. There are two machines now in operation npon glass, andone at work on stone. The emall machine is to appearance a very plain painted box or stand—nothing of machinery visible. In the top of this bor are two holes, ahont an inch and a half in diameter. If tha woodon casings were removed, there might be seen below these holes a pipe, which decends, and is formed somewhat trumpet-moathed on the oatside of the hottomoftha bor. Below this month isa tnrued wooden basin. From the npper part of tha hor, on the spectator'a left hand, a pipe passes nnderneath the floor to the oenter of a rotating fan, near the wall of tha room, and therefore hy this a vacunm can be formed in the box. As the only inlet of air is past the trnmpet moathed opening, a rapid cnrrent asoends the pipe connected with it whenever the exhanst-fan ia at work. From large hoppers (funnel-shsped) containing sand, a regulated quantity falls toward the turned wooden hasin; in falling on the basin it is influeaced by the entering air, is jetted from the pipe, and so strikes npon, say, glass covering the holes; the exposed glass is rupidly depolished, Where, however, an elastio substance as peper, India-ruhber, eto., covers the glass, no aotion of sand takea place. It interstices or openings he formed in this elastic sabstance, as a patteru, then the surface of the glass is removed in accordance with such pattern, and to a depth dependent npon the time of exposure, and the intensity of the carrent of air, and qnality of the sand. Next to this small ‘‘vacnnm" machine is a large compressed air-blast, one oapable of act-ing upon a sheet of glasa three feet broad. A design in paper or lace heiug pasted on the glazs, 1t is laid upon endless bauds, by the motion of which it may he carried forward. In the middle of the compartment (which is glazed upon one side so that spectators may see the operation) provision is made, by a snitahly-formed transverse openiug, for a hlast of alr with sand. When the ordinary machinery is set in motion this blast commences, the glass istraversed at a pre-arranged velocity, and in as little time as one may reqnire to rend this aocount the ornamented glass is delivered at the side of the box opposite to that at whiob it entered, So slightly an elastic surface as the ohanged character of some of the materials used in photography suffices to resist the action of the sand; hence the photographic design may be etched by sand on glass. Examples of varions works done by this process are on the table near to the machine. The third machine is in aseparate building. It consista of a wooden table, on which the stone islsid. This tahle can be traversed impulsively in one direction, by the actiou of a Clement’s driver, on a spur wheel, and so motion is given to a rack, Above the table provision is made for traversing the combined steam and sand jet. This is accomplished by a mangle-wheel motion, variable according to the breadth of the stone to ba operated upon. By these two motions, transverse to each other, every portion of the stone may bereached, The steam and sand jet is arranged npon the plan adopted hy Mr. Siemens, for exhausting the telegraph diapatch tubes—the sand being admitted by an inner small tube, snrrounded by jets of steam, as from concentric rays of an argand hurner, Whilst the writer was present a delicate and somewhat intricate pattern was Isid npon 8 piece of marble. The steam in the hoiler was at 59 ponnds pressure. In five minutes the marble, measnring thirteen inches by six inches, waa penetrated to a depth of about threesixteenths of an inch, leaving the surface as orlginally polished, aud with the “beautifnl tracery desigu in high relief. Crecunan Litsocrarnie Stonz.—Mr. 0. Maurice, of New York, has inveuted a form of lithographic stone for direot printing, which promises to effect a complete revolntion in the att. He boldly discards the ordinary flat stone, and by the use of diamond stoue-working maehiaery produces a solid cylinder, from which, of conrse, impressions may he taken with greater facility and rapidity. In Paris the story goes that the old sardina boxes are gathered np by rag-piokers and sold to builders, who fill them with mortar and use them in the construction of cheap dwelling honses. Where is the economy? Wuear Crecanine Maonrnery.—The agriculturiets of South Anstrslia have resolved to offer a first prize of £1,200, a second of £600 and a third of £300, for the best wheat cleaning machinery. --bos Samra é; Wesson’a establishment at Springfield turns out over 300 revolvers daily.

January 3. 1874-] MINING AND SCIENTIFIC PRESS. §clentiFic ®Procress. iron in Plants and Animals. Every one is familiar with the important part that lron playa in the work-ehops of man, but few are aware of the eqnally important part that it takes in the nperations of natnre—how it answers the same pnrpose in the miunte cells of which all animal nud vegetahle growth is made, as the tools in the hands of the skillful worker. For, so far as onr investigations have shown, Iron forms no essential part cf the plant or anlmal, yet withont lt all growth and assimilation ceise. If sceds are pluced on a little cotton wool in a solution containing all that is essential to plant growth, with tbe oxeeption nf iron, thoy will sprout and grow nntil the lron contained in the sacc itself is exhausted; tbo plaat then qnlokly bleaches aad ocases to grow. If a litthe phosphate of iron, which is almost totally icnalubile: iz added to the solution, and occasionally stirred np so that it may be keptin suspension and thn3 come in contact with the roots, tbn plant quickly revives and continues ita growth. Iron is an essential constitaent of chlorophyl, the groen coloring matter of leaves. Chlorophyl may he aoparated into at least two distinct ies, one green and the other hlue. Professor Horsford is of the opinion that this blne anhbstanco ia vivianite, or phosphate of iron. and gives the following experiment in support of this opinion: He mada a mixture of pbosphata of soda and protosnIphata of iroa, and found that this mixture was capable nf redncing carbonio acid to carbonic oxide, and that crystals of vivianite were formed in the operation. He therefore considers it probable that the formation of phosphato or protoxide of iron may ba a preliminary stage in the prodnotion of vegetahle tissne. There 1s also a well-known native phosphate of iron that is colorless when first mined, hnt on erposnra to light it becomes a beautifal blne. The amoant of iron existing in plants is extremely small. Bonssingaultfonnd that it was more abnndant in the oat thaa any other plant examined; hat thia contained only 131 parts in 1,000,000, while the white part of eabbaye coutained hnt nine parts, tha green ooutaining thirty-nine. Itelso abonnds in plants that are almost perfectly colorless; thus mushrooms contain twalve parts. Although found in all plants, and constitating an essential part of their food, it has never been thonght neoessary to supply it to them artifioally, all soils being snpposed to contain aufficient for their wants. Bnt no one oan have falled to observe the greater Inruriance of vegetation on the strong iron soils derived from the old red sandstone than on those granite soils which are comparatively free from it. It was long supposed that the red color of the blood was owing to the iron contained in it, but Malder and Vau Gnodoever fonnd that they ooald extraot the iroucompletely from the red coloring matter withont ‘destroying it. Moreover, the blood of an oyster also contains iron, althongh it is perfectly colorless. The want of iron in the system constitntes a disease which is well known to physicians nnder the name of chlorosia, and many remedies have been proposed for it. This want mnst generally arise from a defeotive state of the organs of assimilation; therefore it will be of little benefit to administer iron aloue, without adding to it dome other stimulating tonio, Varions preparations of this kind have from time to time been offered, and among these the various comhinations of iron and quinine have long held @ prominent place. These componnds should nll contain more or less of the metal in the form of protoxide, as the protoxide seems to be much more readily absorbed than the higher oxide; and they shonld be free from the well kuown inky taste generally possessed hy all compounds containing iron, The dose of ironshonld he small, and its use oontinued for some time. The amonnt which is necessary for a healthy man, and whioh he ohtains from his food, is from .9 to 1.5 grains per day, and it is probable that the dose should not greatly exceed this amonnt.—Journal of Chemistry. Smicon Srezu.—Mr. Calvin Pepper, au American experimentalist, claims to prodnce a true silicon steel by imhedding wronght iron bars in sand aud snhjecting them to a very high temperature, which canses the metal to part with its carhon inthe form of carbonic oxide, and to take up silicon from the sand, thus oonverting it into silicon steel. The Iron Age remarks on the snbject: '* This, at least, is what we understand to he his claim, aud as he asserts that he has accomplished what he claims, producing a true silioon steel by this method from wrought iron, we are not disposed to qnarrel with his theory untilwe have had opportunity of examining his prooess and testing the metal prodnced."" rs In 1867 M. Rabnteau announced that the poisonous power of the metals was greater as their atomic weights were higher and their epecifio heats were lower. This he now substantiates by additional discoveries, among them the toxic relation of potassium and calcinm, Iz is said that wheu alcohol is taken inter. nally, the temperature of the body siuks. With small quantities this lowering of temperature is 0,6° and somewhat more; in drunkenness a lowering of 2° has been noticed, The Behavior of Metais under Stress. Interesting and important resulta have been nbtaincd in the conrse of ths investigations iu progress at the Stevens Institnte of Technology npon the behavionr nf metals nnder stress, The testing machine invented and designed by Professor Thurston, with his antomatio rogistry, was descrihed in onr issne nf April last, and its pecniiar valae in detecting all phenomena of stress, and in affording a reliahlo and permauent record, ls shown by inspection of the curves giving in tbe plate accompanying that article. The apparatus was exhibited at the last mecting of the National Academy of Science, which was held at the Steveas Iastitnte, and its oapability of revealing tho aotion of moleenlar forces under stress was linstrated. At tha closo of the session a test piece was left in the machine, strainod far heyond its limit of elasticity, to determine, if possible, the existence or non-existence of “visoosity’’ in the metals. After twenty-fonr honrs, there appearing no evidence of further yielding, tha distorting foree was inoreased, when the discovery was made that the resisting power of the specimen had netnally become greater during the period of rest under strain, and the penoil, instead of doscending, rose nntil it indicated an increase of ahont twenty per cent. ia the strength nf tba sample, and it then traced a path parallel with but above that of the previons day. Repeated experiments confirmed this remarkable and important deduction of the experimenter: That metal strained so far as to take a permanent set, and left under the atress prodnducing it, gaina in power of resistance np to 8 limit of time, which in those experiments was abont seventy-two honrs, and to a limit of inorease whioh has a value, in the best iron, of abont 20 per oent., where the applied force is eighty per cent. of the nltimite breaking force. In other words, the metal develops nearly or quite its maximnm strength long before reaching the poiut of rnptnre, instead of at that point, 2s when brokeu at once by 2 continually increasing streas. This discovery was annonnced by Professor Thurston at the annaal meeting of the American Sooiety of Civil Engineers, November 5th, and the possible bearing of the earlier experiments of the Committee of the Franklin Institate on ‘’'Thermo-Tension,"’ and of the wellknown property of the inoreasing portative force of magaets under atrain, as illnstrations of related phenomena, were alluded to. The existence of this property had already been anspected, bnt itis evident that it could only be conclusively proven by apparatus embodying the principles of that used iu this research.— Journal of the Franiclin Institute. New Meruop or Enoravive.—J. Lnther Ringwalt, of Philadelphia, patented, in July, a new method of engraving typographic plates, or pictures, on zine, which he has successfully applied to the prodnction of book and newspaper illustrations, ornamental lettering, miscellaneons job work, show oards, etc., varying in size and fineness from small vignettes to half-sheet posters. He recently gave a detailed description of his process at a meeting of the Franklin Institate, on which occasion he had drawn and engraved, in thirty minntes, on a prepared plate, a portrait of Dr. Franklin, of nearly life size. Under his system, a zine plate is covered with a varnish capable of resistiag the action of the acid, through which a series of lines are drawn by a ruling machine at snch intervals as are required by the general character of the pictnre to be produced, thus Opehing up avenues iu which the acid can make the desired incisions; the shape, thickness, position and direction of these lines or scorings heing readily varied to suit different classes of work. The artist then draws npou this surface the desired design, creating additional blacks by applying a protecting liquid with a pen or brush at the points where additional blacks are reqnired, and removing the original groand, with an etching point or scrapcr, from the places where additional whites are necessary. This operation involves but little more labor than the prodnetion of a drawing on paper, and the character of the engraviag depends npon the degree of skill with which it is performed. The plate is next snbjected tothe action of the dilute acid, and at this stage a variety of tints can be prodnced by etching some portions of the work deeper and widar thau otbers. The process is so simple and inexpensive that it could readily be applied in any printing office which cau command art assistance.—Newspaper Reporter. Suoxe Consummd.—Some interesting experiments were lately made in Ohio, with a view to ascertaiuing the best method of consnming the smoke of soft coal furuaces, and, after a earefnl examination and test of a nnmher of mechanical appliances desigued to effect this object, the conclusion was reached that nothing was so simple and effective in preventing the escape of smoke as the introduction of sufficient oxygen into the furnace to effect complete comhustiou of the fuel, aud thns prevent the formation of any smoke at all, __A New Exprostve.— Ozobenzin is the name given by MM. Houzeau and Renard to a new

explosive sabstance. It is produced by aoting npou benzin, boiling at 81° cent., with oncentrated ozone; formic and acetic acid are prodnced, and a gelatiuons precipitato formed, which, being dried in vacuo, becomes a white solid, which is the explosive compound named. It detonates violently when struck or when simply heated. It is unstable in the air; water decomposes and dissolves it. Ni ECHANICAL B roGRESS Small Motor Machines in Europe. The demand for an economical and convenient small motive power is felt and appreoiated throughont the civilized world. In this conntry we havo several patented inventions in this field, ntilizing steam, hot-air, gas and water, as the means of gencrating or conveying the force. We have also devices for storing np force where vory small power is reqnired, as for sewing-maohines, eome storing the powcr ina wonnd-up spring, a weight, in compressed air, or inn vacnum oylinder. Of the principal devices for small motive power in Europe, and exhihited at the Vienna Expositlon, may bo mentioned the following: Messrs. Otto & Laagen, in Gormany, and M. Lenoir, in France, niake 8 machine which is driven by the explosive force of lightiag gaa; Mr. W. Lehman, in Germany, constrnots n hotsir machine which claims to benn improvement npon the idea of our American engineer, Capt, Ericsson; whilo M. Hermon La Chapelle, in Paris, and others more conservative, bnild diminntive steam-engiaes. The gas-engine of M. Lenoir in external appearance resembles a horizontal steam-engine, and indeed is nearly the snme internally, having the same parts, piston, oylinder, valves, eto., but the power is ohtained hy exploding a mixtore of gas and atmospherio sir in the eylinder. During the first half of each stroke the piston sncks into the cylinder air and gas in the right proportions. At the half stroke the mixture is exploded by an electrio spark, whioh forces the piston throngh the remainder of the stroke, Messrs. Otto & Langen's machine consists of an upright cylinder, open at the top, in which plays vertically a piston having a ratcheted rod, so arranged asin the down stroke to engage a cog-wheel, attached to the arzle of the fly-wheel of the machine. The piston, during a amall portion of its upward course, takes in the rightly-proppnign qd mixture of gas and air, which is exploded at the point of the piston’s course, where the mixtnreis shut off. Explosion of the mixture carries the piston upward until the pressnre of the external atmosphere stops it. The explosion, depending upon expansion of gases by heat at the instant of combination, is immediately followed by a condensation and partial yaounm in the cylinder. The pressure of the atmosphere npon the pistou forces it downward, and the ratcheted rod, engaging the cog-wheel, imparts this force to the fly-wheel. Itis claimed for this machine that it is much more economical of gas thau M. Leuoir's. The complications incident to the ratchet and cogwheel arrangement are ohjectiouable; bnt it is spoken of as having qnitean extended nse. he cousnmption of gas is abont a cubic meter (39.31 cubic feet) per horse-power per honr, With gaa at $3.50 per thonsand this would give nine-six cents per day per horse-power. Of the small water motors, that of Mr. Schmid, in Zurioh, a small oscillating water engine is well spoken of. It is on ahont the same principle as the oscillating stenm-engine ; having, of conrse, mnch larger valve-ports. It hardly need be remarked that the water-engine can only be used where a small supply of water with considerable head is at hand, aais the case in cities where the cost of water is not too great. In Zurich, where the water is snpplied by a pump, worked by eighty horse power, the Schmid engine has come qnite extensively into nse. The water column motor of Mayer, in Vienna, also designed for light work, is iu prinoiple like a horizoutal steam-engine. The arrangement of the regulator and air-cnshion, for the pnrpose of avoiding the hydraulic shock incident to snch engines, is quite ingenious. The machine requires more space than that of Schmid’s, The emall turbine wheels of Messrs, Escher & Wyss, and of Mr. Gwynne, are also designed for the utilization of power furnished by a water column ona small scale. The hot-air machine of Lehman claims to have an advantage over the Ericsson engine in an arrangement by which the air in immediate contact with the piston is never heated ahove 30° Cent. (86° Fahr.), thus saving the packing and lubricating materia! of the piston. Beyoud this advantage it is not easy to see the superiority. + ‘Then oome the small steam-eugiues of M. Herman La, Chapelle, in Paris, which have nothing remarkahle about them, except that they are small and well made. It is very questiorable whether, when people come to learn that small steam-engines can be made perfectly safe, and can be rnu withont any extraordiuary skill or judgmeut, the advantages of all the so-called improved motors willseem so great as at present. For most cares where small motive power is needed, the small steam-engine, if well devised, and well made, is the cheapest and the best.— Artisan. Ir is stated that the quantity of coal necessary to raise a million gallons of water 100 feet, varies iu England from 17 ewt. to 114 cwt.; this is said to be due to the varying qualities of coal nsed, but more particularly to the construction of the pumping engines. Two monitors are being constructedat Bremen for use on the Rhine. They are covered with a one iuch plating—a sufficient protection agaiust infantry fire, and, it is thought, egaiust field artillery. They will draw only five feet of water. Sand Blast Engraving. The British Trade Journal seems pleased with Tilghman’s contrivance for engraving on glass, by means nf sand blast. It is a Phila: delphia invention, lately on exhibition at tha London International Exhibition. The principle of the apparatus is by a blast of air, steam, &c., to canse innumerable particles of sand to impinge where portions of glase, stone, metal, &o., are to be removed. Mr. Tilghman is thus enabled to produce not only excellent work, but with a rapidity almost incredible. For example, a sqnare or triangniar hole of half an inch in the side can ba bored throngha sheet of ordinary plate window glass in less than one minute. Designs of lace work—also photographs—can be ‘’eroded’’ or '‘gronnd’’ on glass with great rapidity. There are two machines now in operation npon glass, andone at work on stone. The emall machine is to appearance a very plain painted box or stand—nothing of machinery visible. In the top of this bor are two holes, ahont an inch and a half in diameter. If tha woodon casings were removed, there might be seen below these holes a pipe, which decends, and is formed somewhat trumpet-moathed on the oatside of the hottomoftha bor. Below this month isa tnrued wooden basin. From the npper part of tha hor, on the spectator'a left hand, a pipe passes nnderneath the floor to the oenter of a rotating fan, near the wall of tha room, and therefore hy this a vacunm can be formed in the box. As the only inlet of air is past the trnmpet moathed opening, a rapid cnrrent asoends the pipe connected with it whenever the exhanst-fan ia at work. From large hoppers (funnel-shsped) containing sand, a regulated quantity falls toward the turned wooden hasin; in falling on the basin it is influeaced by the entering air, is jetted from the pipe, and so strikes npon, say, glass covering the holes; the exposed glass is rupidly depolished, Where, however, an elastio substance as peper, India-ruhber, eto., covers the glass, no aotion of sand takea place. It interstices or openings he formed in this elastic sabstance, as a patteru, then the surface of the glass is removed in accordance with such pattern, and to a depth dependent npon the time of exposure, and the intensity of the carrent of air, and qnality of the sand. Next to this small ‘‘vacnnm" machine is a large compressed air-blast, one oapable of act-ing upon a sheet of glasa three feet broad. A design in paper or lace heiug pasted on the glazs, 1t is laid upon endless bauds, by the motion of which it may he carried forward. In the middle of the compartment (which is glazed upon one side so that spectators may see the operation) provision is made, by a snitahly-formed transverse openiug, for a hlast of alr with sand. When the ordinary machinery is set in motion this blast commences, the glass istraversed at a pre-arranged velocity, and in as little time as one may reqnire to rend this aocount the ornamented glass is delivered at the side of the box opposite to that at whiob it entered, So slightly an elastic surface as the ohanged character of some of the materials used in photography suffices to resist the action of the sand; hence the photographic design may be etched by sand on glass. Examples of varions works done by this process are on the table near to the machine. The third machine is in aseparate building. It consista of a wooden table, on which the stone islsid. This tahle can be traversed impulsively in one direction, by the actiou of a Clement’s driver, on a spur wheel, and so motion is given to a rack, Above the table provision is made for traversing the combined steam and sand jet. This is accomplished by a mangle-wheel motion, variable according to the breadth of the stone to ba operated upon. By these two motions, transverse to each other, every portion of the stone may bereached, The steam and sand jet is arranged npon the plan adopted hy Mr. Siemens, for exhausting the telegraph diapatch tubes—the sand being admitted by an inner small tube, snrrounded by jets of steam, as from concentric rays of an argand hurner, Whilst the writer was present a delicate and somewhat intricate pattern was Isid npon 8 piece of marble. The steam in the hoiler was at 59 ponnds pressure. In five minutes the marble, measnring thirteen inches by six inches, waa penetrated to a depth of about threesixteenths of an inch, leaving the surface as orlginally polished, aud with the “beautifnl tracery desigu in high relief. Crecunan Litsocrarnie Stonz.—Mr. 0. Maurice, of New York, has inveuted a form of lithographic stone for direot printing, which promises to effect a complete revolntion in the att. He boldly discards the ordinary flat stone, and by the use of diamond stoue-working maehiaery produces a solid cylinder, from which, of conrse, impressions may he taken with greater facility and rapidity. In Paris the story goes that the old sardina boxes are gathered np by rag-piokers and sold to builders, who fill them with mortar and use them in the construction of cheap dwelling honses. Where is the economy? Wuear Crecanine Maonrnery.—The agriculturiets of South Anstrslia have resolved to offer a first prize of £1,200, a second of £600 and a third of £300, for the best wheat cleaning machinery. --bos Samra é; Wesson’a establishment at Springfield turns out over 300 revolvers daily.