Volume 24 (1872) (424 pages)

April 20, 1872.] SCIENTIFIC PRESS. 243 eed ag MECHANICAL ‘PRoGRESS Utilization of pita Clippings (Tinners’ Waste). Tin-plate consists of iron covered with puro tin, or an alloy of tin and lead. The iron is of very superior quality. Thotest to which it is submitted is that it must bear bending at a sharp angle withont cracking, and when hent nnder the hammer light must not shino throngh any creviccs along tho line of flexion. The proportion of tin in tin-plate varies according to quality from 3 to 7 per cent. The valuo of tin in tho waste is about eqnal to that of the iron. Several methods for treating tinners’ wasto have already heen dovised. In 1848, Schunk proposed three processes, of which the firet was to boil the clippings in sulphide of sodium, tho second to boil insoda-lye, in which litharge was suspended, aud tho third to heat in a lye of chromato of potash and caustic-potash. In 1854, Jas. Higgin patented a mixture of hydrochloric acid, and solution of nitre, hy which means it was expected that the tin would bo dissolved with less action npou the iron than in hydrochloric acid alono. In 1857, Parkes proposed to put tho clippings into mercury in a revolving shect-iron drum, and thus colloct the tin in an amalgam. In 1863, Paterson patented a process for mixing the clippings with fused lead so as to form solder. By heating the mass again, the alloy is fused off. Standevant and Harman proposed to melt off the tin in a current of steam and hot air into an iron cylinder below; but all these methods seemed to present some radical objection. A perfect method for treating tin cuttings should fulfil four conditions. 1. The iron mnst bo free from tin, 2. The tin must be obtained in a marketable form, and preferably in the metallic state. 3. Large quantities must be capable of treatment at once without much labor, 4. Tho proccss muet be cheap. Iron containing 0-5 per cent. of tin, thongh it can be forged and welded is very cold-short. It has a fine-grained steel texture, a clear ring and great hardness, but can be useful for very few purposes. None of the old processes, except that of Higgin, thoroughly remove the iron. Schnok obtains the tin iu an nnsaleable form, and hls process can be used on a small scale only. Mr. Ott has recently devised a method which has been applied to 300 tons of clippings in three months. The tin waste is put into a drum of thick copper, provided with holes %-inch in diameter, and two inches apart. It contains 1,000 ths. of clippings. It isthen made to revolve in a bath of acid in which the tin is dissolved off. Then the drum is lifted out by a crane, and made to revolve in @ water-tank, then in an alkaline bath and then in water again. In the acid bath it revolves according to the amount of free acid, from 5 to 50 minutes, and in the others 5 minutes each, making with the time spent in lifting the drum a total of 70 minntes. So, as the drum contains 1,000 ibs. of clipping, it is possible ina day of 10 hours to treat 90 ewt. In the acid, the tin, the lead, and ahout5 per cent. of ironare taken up. This solution is let off intosuitable tanks. The lead is separated first, and then the tin is obtained in a state of purity, by putting in plates of zinc, when it is thrown down either in a crystalline or a spongy form. It is well washed, fused and sold as block tin. The zinc remains in solution, one part of zine being required to precipitate two of tin. The mixed solution of zine and iron may be used for preserving wood, or for making coarse colors for house-painting. The iron plutes are sold to the iron works. Dorn proposes to pilo up tin clippings in chambers of a suitable material, and to dissolve off the tin by means of a gaseous mixture, On this process, it may be remarked, that though the bichloride of tin is extensively used by color-makers, dycra and calico-printers, it is necessary that it should be perfectly free from iron. The Production of Bright or Lustrous Colors on Metals. The active chemist, C. Puscher, of Nuremburg, proposes a new method of coloring metals which can be executed quickly and cheaply. He produces on those surfaces a coating of metallic sulphides analogous to those found in nature, as for example, sulphide of lead. These very stable snlphur combinations, as is well known, are not affected by ordinary agents. According to Puscher’s method, in five minutes there may he imparted to thousands of brass articles a color varying from a beautiful gold to a copper red, then carmine red, then dark, then analine blue, to a blue white, like sulphide of lead, and at last a reddish white, according to the length of time they remain in the solution used. The colors possess the most beautiful lustre, and, if the articles to be colored have been previonsly thoronghly cleaned by means of acids and alkalies, they adhere so firmly that they may be operated upon by the polishing steel. prepare the solution, dissolve 144 ounces of hyposulphite of soda in one pound of water, and add 14% ounces acetate of lead disaolved in half a pound of water. When this clear solution ia heated to 190° to 210° F., it decomposes slowly and precipitates sulphide of lead in To . brown flocks. If metal is now present, a part of the sulphide of lead is deposited thereon, and according to the thickness of the deposited sulphide of lead tho above mentioned heautiful lustro colors aro produced. To produce an even coloring, the articles to he elon must be evenly heated. Iron treated with this solution takea a steel blne color; zinc, a brown color; in the case of copper objecte, the first gold color does not appear; lead and zinc are entirely indifferent. If, instead of the acetate of lead, an cqual woight of sulphuric acid is added to the lyposulphite of soda and the process carried on as before, the brass is covered with a very beautiful rod, which is followed by a green, which is not in the first mentioned seale of colors, and changes finally to a splendid brown with green and red iris glitter; this last is a vory durahle coating, and may find special attention in manufactures. Very beautiful marhleized designe can he produced by nsing a lead solution thickened with gumtragacanth on brass which hae been heated to 210° I’., and is afterward treated by the usual eolution of sulphide of lead. Tbe solution may be used soverul times, and is not lable to spontancous change.— Technologist. Glass Bearings. The uso of glass bearings for the wearing surfaces of cross-beads, pistons, and other working parts of machinery which has recently hoon introduced into some parts of the Eastern States is steadily extending and gaining favor. These Bearings consist of pieces of glass inserted into the hearing surfaces as hereinafter described. In the slides of the cross-head they are simply imbedded ia holes drilled or cast to receive them, and in piston rings they are in serted in grooves turned in the rings. The following directions are given by the manufacturer for pntting in such bearings: “Drill the holes full one-fourth of an inch larger; in diameter than the glass is, and at least one-sixteenth deeper thau the glass is thick. The holes should be chipped nnder with a center chisel in soveral places in order to hold the babbit well. Then take a parallel pieco of iron largo enough to cover tbe hole, and perfectly smooth on one surface, place a little oil on the smooth surface and press the piece of glass to it. By this means you exclude the air, and the glass and iron will stick together firmly; this is done in order to hold tbe glass up from the bottom of the hole, and thus allow the babbit to run under as well as around it, forming a perfect bed for the glass to rest on. Place the piece of iron with the glass fast to it over the hole}in such a manner as to keep the glass in the centor, and also leave a small space uncovered through which to pour the babbit. The glass should be above the surface of the working part, in order to take the full bearing. Place at least one thickness of writing paper between the parallel piece and the other surface; clamp the parallel piece to the gibb or other part, for if not clamped the glass is likely to rise too high above the surface while the habbit is being poured. Caulk the babbit in several places with a blunt center-punch between the glass and iron, theu scrape it down to tho surface. Bearings put iu locomotive cross-heads should not be more than flush with the surface. To insert tho bearings in cylinder packingrings, eccentrics, etc., a groove should be cast or turned in the center of sufficient depth and width to allow the babbit to run under and around the glass; the groove should be turned nnder and also chipped rough on the sides, Then bend a strip of sheet-iron to the exact radius, and make the proper surface smooth, then stick five or six pieces of glass to the smooth surface by means of putty or any other substance that will stick well. Then clamp the sheet iron with the glass fast to it to the ring or other part; close up one end with putty, and pour the babbit inthe other end. When the plass is all inserted, take oil and emery with a file and grind the glass down to the surface, making sure that not one of the glasses are above the surface when the ring is finished. In parts where there is not sufficient thickness of material to allow the babbitt metal to he run under the glass, one thickness of muslin may be used as a bed for the glass to rest upon.” These bearings are now very exteusively used in locomotives and stationary engines, and the manufacturer is furnishing them to all parts of the country and for all kinds of steam-machinery. Most persons, we believe, would be surprised to find how much rough nsage a piece of glass will bear if properly embedded in a soft metal. If they are well fitted they will stand a considerable number of quite severe blows from a hammer without being fractured. THE manager of a furnace in Prussia, fiuding himself without fuel, resolved to kcep the fnrnace alive as hest he might. He hegan at once to reduce the charge of iron ore to onehalf, keeping all the whlle the nsual charge of coke, and after the furnace was thus filled, the blast was cut off, and all apertures were closed as air-tight as possible, and watched carefully so for more than ninety days anxiety. A regular supply of fuel being once more secured, after that time, the tuyers, hearth, and top wero reopened, the hot blast let on, and twelve hours later the first clean cinder made its appearance, flowing over the wall-stone, to the great delight of all concerned. A Prussian engineer has, it is aaid, invented a machine which will manufacture ice withont chemicals, merely by compression and explosion of air, ng f HCIENTIFIC Progress. Tue Speernoscore ox tne Nesutar HyrotuEsis,—Tho existence of immense nebulous masses, from which Laplace snpposed the solar system to have heen derived, was thought to have been proved basclees by the iucrcased power of modern telescopes, which havo resolved into clusters of stars many objects supposed to have been nebule. But since the spectroscope has been so improved as to he practically employed for determining the character of such distant bodies, the nvbulous thoory is again coming into favor, if indeed it may not now he considered as fully established on a stronger foundation than ever hefore. Prof. Kirkwood has made oxtended ohservations in this direction, in which the evidence in favor of the hypothosis is decidedly cumulative. Even progressive changes in the physical condition of eome of the aebulm have heen quite clearly indicated. In some parts of certain nebulw nuclei have been established—the mass of gaseons matter evidently passing from ite attenuated form into a semi-solid state. The speetra obtained prove this fact beyond the possibility of douht. This clasa of spectra reveals a constitution similar to that recently observed in certain comets belonging to onr own system. Vetociry or Mrreorre Srones.—It has been quite satisfactorily proven that meteors, before they meet with the retarding influence of the earth’s atmosphere, often move with a velocity several thonsand times that of a cannon ball at the instant of its discharge. If a cannon ball could be made to move with such velocity it would almost instantly be destroyed, and disappear ina streak of flame. It is probable, however, that the impetus necessary to impart such a velocity would at once reduce to powder any brittle substanco like cast iron or stone. Meteors which enter the atmosphere at any considerable angle from a direct line toward its center are deflected from their course and soon move from its influence. Such is no doubt the caso with many which are seen to flit across the sky; while many, if not most of those whicb enter in a direct line, are dissipated into impalpable gasses before they have passed half the distance from the solar bounds of the atmosphere to the earth, or reach the earth in a state of impalpable dust. Eruption oF MrrroritEs rrom TEE Sun.— The theory of a solar origin for meteorites, however strange and startling it may at first sight be, cau by no means be condemned as altogether illusory. Advocated by Mr. Proctor in Fraser’s Magazine, for April, 1871, much evidence in its favor has heen supplied by the recent solar researches of Secchi, Young and others. In brief, it is, that the solar prominences result from the shooting forth of liquid or solid masses orstreams of matter, and that metcoric masses, or at least some meteorites, may have originated in this manner, being propelled from beneath the surface of the sun. Mr. Runyard, in a recent communication to the Royal Astronomical Society, discussing the nature and origin of the upheaval of eruption prominences, states as his conclusion that the observed phenomena, and all other considerations, go far to render it probable that meteors are formed from the metallic vapors hurled from the sun or other stars, or that solid masses may be so hurled, in eruption prominences. Mr. F. A. Fleming also remarks of this theory, that, offering as it does a possible account of the genesis of prominences and meteorites, it appears also to contain the germ of another hypothesis, which he develops, respecting the cause of the connection between solar eruption and terrestrial magnetism. Tur Transtr or Venus.—Professor Henry and other scientific men connected with the Smithsonian Institute and the Naval Observatory haye nnitedin an interesting memorial to Congress urging the appropriation of $150,000 to make extensive and tborougb preparation for observing the transit of Venus across the sun, which will take place in 1874, which is looked upon as the most important astronomical event that has occurred for many years.’ The last transit was in 1792, and excited so much interest in the scientific world that seyoral European Governments made liberal appropriations to enable their astronomers to take observations. The transit of 1874 will not be visible in this country, and will be best seen from the islands of the South Pacific and Indian oceans. It is proposed to send naval expeditions to those points, accompanied by scientific parties. The Governmeuts of many of ,the conntries of Europe have already taken steps to this end, and there is little douht that Congress will enable the astronomers of this country to have the same advantages as their foreign hrethren. Tue proposed tunnel nnder Mt. St. Gothard will be ahout twice as long as the Mt. Cenis tunnel, andit will pass under peaks varying in hight from 8,750 feet to 10,000. The principal advantage anticipated from the work is an increase in the facilities for trade and travel between Europe and Asia, by way of Italy. Passtvirr or Inox, CapMivm, aNp Trx.—Many yeurs ago Faraday pointed out that when iron was plunged into nitric acid sufficiently concentrated, it became possessed of a surface condition which rendered it indifferent to the strongest acid; and which enahled it to form a voltaic circuit with ordinary iron. That such iron has really heen decidedly altered in character is also evinced hy the fact that it refuses to reduce copper from solution of its salts. Dr, Schin has observed that if cadmium is wrapped round with some platinum wire, it may be placed in strong nitric acid without being in tbe least degroe acted upou; but if tho wire is removed the cadmium is instantly attacked, thus showing that the passivity of the cadmium is entirely due to its contact with the platinum. The author also states that when tin is treated in a similar manner it exhibits ike pheuomena. Daxcrnovus Gas Prprs.— The Journal de UEclairage notices an accident which gives new proof of tho danger attending the uso of copper gas pipes. In April last, a workman haviag with a triangular tlle ent almost half through a gas-pipe of red copper 3% inch interior diameter, which supplied the Liege station, was removing the tool, when an explosion took place, with a noise like the report of a rifle, and the workman wae much burnt. A similar accident happened subsequently, hut with lessintensity, and the workman, who was not injured, did not report the circumstance. Some gas-pipes having heen taken down, they were found covered with a blackish coating, and they showed evident signs of corrosion from ammoniacal condensation. The hlack matter was analyzed, and was found to consist of acetylide of copper, which explodos between 203 deg. and 248 deg., producing water, copper, carbon, carbonic acid, and traces of carhonic oxide, Tue Esry Rar Tueory.—It is stated that notwithstanding the continued and wide-spread fires which prevailed for four or five weeks in Northern Illinois, last summer, devastating forests over a large area, not a drop of rain fell, as might have been expected, if the Espy rain theory is correct. The rain only came with a change of wind to northward, and seveee after the worst burnings were over witb. On the contrary, heavy rains followed immediately after the great firoin Chicago. Possibly the occurrence of rain in the latter instance was due to the greater intensity and concentration of heat. UNEXTINOUIsHABLE Sianat Lawp.—Some experiments have been made in Tamise, with the unextinguishable self-lighting signal lamp of Holmes, and they promise a great snccess. The lamp is a cylinder of tin, with a conical top; the cylinder is filled with phosphuret of calcium, prepared by the inventor. When the lamp is plunged in water, this quid, entering the cylinder, effects the decomposition of the phosphuret; phosphuretted hydrogen is disengaged in large quantity with vapor of phosphorus, takes fire spotaneously, and burns with a brilliant flame.—Les Mondes. Crzanstna Woor. From Burrs.—The wool is soaked in a bath containing 2 ibs. alum to every 10 ibs. of wool and to this sulphuric acid added untilthe bath marks 6 deg. B. In this bath the wool shonld remain until its appearance shows that the bath has had its effect, when it must be taken out and thoroughly drained. It is then subjected to the action of a brushing machine which removes all the burrs. THE GREENLAND Meteorites. — Professor Nordenskiold states that the masses of meteoric iron brought from Greenland by the recent Sweedish expcdition soem to have formed the principle masses of enormous meteoric fall of miocene date, extending over an area of some two hundred square miles, The iron appears tobe free from silicates. Professor Ramsey thinks the masses may be of tellurie origin. Aw Acoustic EXPERTIMENT.—Let a wide glass tube, open at both ends, he taken, and in thisa piece of fine wire gauze be pusbed up some little distance. If the gauze isnow heated to redness over an ordinary Bunsen burner, and then removed, it will shortly emit a shrill note, lasting from 5—10 seconds. The experiment we believe will be new to most of our readers, and has the merit of always going off. An EXPERIMENTAL Gas Worrs.—The Germau Society of Gas and Water Experts have under consideration a plan for establishing an experimeutal gas works, for the purpose of deciding various questions which may arise in the details of their profession, by actual experiment. The proposed plau, if adopted, will be upon a large scale, so asto reproduce, as faras possible, all the conditions met with in practice. Lancs Sun Spor.—Professor S. P. Langley of the Alleghany Observatory, has computed the area of one of the spots lately visible near the center of the sun’s disc, from careful measurement, and found it exceeded 2,300,000 square miles, which is more than ten times the entire area of the earth. Renova of spots made by sugar, from goods with delicate colors and much sizing. Thespot should be rubbed with a damp cloth, and then with a piece of fresh bread, which will remove the saccharine matter without affecting the color. Tue principal supply of bismuth is derived from Bolivia, but it has recently :been discoyered in Australia.

April 20, 1872.] SCIENTIFIC PRESS. 243 eed ag MECHANICAL ‘PRoGRESS Utilization of pita Clippings (Tinners’ Waste). Tin-plate consists of iron covered with puro tin, or an alloy of tin and lead. The iron is of very superior quality. Thotest to which it is submitted is that it must bear bending at a sharp angle withont cracking, and when hent nnder the hammer light must not shino throngh any creviccs along tho line of flexion. The proportion of tin in tin-plate varies according to quality from 3 to 7 per cent. The valuo of tin in tho waste is about eqnal to that of the iron. Several methods for treating tinners’ wasto have already heen dovised. In 1848, Schunk proposed three processes, of which the firet was to boil the clippings in sulphide of sodium, tho second to boil insoda-lye, in which litharge was suspended, aud tho third to heat in a lye of chromato of potash and caustic-potash. In 1854, Jas. Higgin patented a mixture of hydrochloric acid, and solution of nitre, hy which means it was expected that the tin would bo dissolved with less action npou the iron than in hydrochloric acid alono. In 1857, Parkes proposed to put tho clippings into mercury in a revolving shect-iron drum, and thus colloct the tin in an amalgam. In 1863, Paterson patented a process for mixing the clippings with fused lead so as to form solder. By heating the mass again, the alloy is fused off. Standevant and Harman proposed to melt off the tin in a current of steam and hot air into an iron cylinder below; but all these methods seemed to present some radical objection. A perfect method for treating tin cuttings should fulfil four conditions. 1. The iron mnst bo free from tin, 2. The tin must be obtained in a marketable form, and preferably in the metallic state. 3. Large quantities must be capable of treatment at once without much labor, 4. Tho proccss muet be cheap. Iron containing 0-5 per cent. of tin, thongh it can be forged and welded is very cold-short. It has a fine-grained steel texture, a clear ring and great hardness, but can be useful for very few purposes. None of the old processes, except that of Higgin, thoroughly remove the iron. Schnok obtains the tin iu an nnsaleable form, and hls process can be used on a small scale only. Mr. Ott has recently devised a method which has been applied to 300 tons of clippings in three months. The tin waste is put into a drum of thick copper, provided with holes %-inch in diameter, and two inches apart. It contains 1,000 ths. of clippings. It isthen made to revolve in a bath of acid in which the tin is dissolved off. Then the drum is lifted out by a crane, and made to revolve in @ water-tank, then in an alkaline bath and then in water again. In the acid bath it revolves according to the amount of free acid, from 5 to 50 minutes, and in the others 5 minutes each, making with the time spent in lifting the drum a total of 70 minntes. So, as the drum contains 1,000 ibs. of clipping, it is possible ina day of 10 hours to treat 90 ewt. In the acid, the tin, the lead, and ahout5 per cent. of ironare taken up. This solution is let off intosuitable tanks. The lead is separated first, and then the tin is obtained in a state of purity, by putting in plates of zinc, when it is thrown down either in a crystalline or a spongy form. It is well washed, fused and sold as block tin. The zinc remains in solution, one part of zine being required to precipitate two of tin. The mixed solution of zine and iron may be used for preserving wood, or for making coarse colors for house-painting. The iron plutes are sold to the iron works. Dorn proposes to pilo up tin clippings in chambers of a suitable material, and to dissolve off the tin by means of a gaseous mixture, On this process, it may be remarked, that though the bichloride of tin is extensively used by color-makers, dycra and calico-printers, it is necessary that it should be perfectly free from iron. The Production of Bright or Lustrous Colors on Metals. The active chemist, C. Puscher, of Nuremburg, proposes a new method of coloring metals which can be executed quickly and cheaply. He produces on those surfaces a coating of metallic sulphides analogous to those found in nature, as for example, sulphide of lead. These very stable snlphur combinations, as is well known, are not affected by ordinary agents. According to Puscher’s method, in five minutes there may he imparted to thousands of brass articles a color varying from a beautiful gold to a copper red, then carmine red, then dark, then analine blue, to a blue white, like sulphide of lead, and at last a reddish white, according to the length of time they remain in the solution used. The colors possess the most beautiful lustre, and, if the articles to be colored have been previonsly thoronghly cleaned by means of acids and alkalies, they adhere so firmly that they may be operated upon by the polishing steel. prepare the solution, dissolve 144 ounces of hyposulphite of soda in one pound of water, and add 14% ounces acetate of lead disaolved in half a pound of water. When this clear solution ia heated to 190° to 210° F., it decomposes slowly and precipitates sulphide of lead in To . brown flocks. If metal is now present, a part of the sulphide of lead is deposited thereon, and according to the thickness of the deposited sulphide of lead tho above mentioned heautiful lustro colors aro produced. To produce an even coloring, the articles to he elon must be evenly heated. Iron treated with this solution takea a steel blne color; zinc, a brown color; in the case of copper objecte, the first gold color does not appear; lead and zinc are entirely indifferent. If, instead of the acetate of lead, an cqual woight of sulphuric acid is added to the lyposulphite of soda and the process carried on as before, the brass is covered with a very beautiful rod, which is followed by a green, which is not in the first mentioned seale of colors, and changes finally to a splendid brown with green and red iris glitter; this last is a vory durahle coating, and may find special attention in manufactures. Very beautiful marhleized designe can he produced by nsing a lead solution thickened with gumtragacanth on brass which hae been heated to 210° I’., and is afterward treated by the usual eolution of sulphide of lead. Tbe solution may be used soverul times, and is not lable to spontancous change.— Technologist. Glass Bearings. The uso of glass bearings for the wearing surfaces of cross-beads, pistons, and other working parts of machinery which has recently hoon introduced into some parts of the Eastern States is steadily extending and gaining favor. These Bearings consist of pieces of glass inserted into the hearing surfaces as hereinafter described. In the slides of the cross-head they are simply imbedded ia holes drilled or cast to receive them, and in piston rings they are in serted in grooves turned in the rings. The following directions are given by the manufacturer for pntting in such bearings: “Drill the holes full one-fourth of an inch larger; in diameter than the glass is, and at least one-sixteenth deeper thau the glass is thick. The holes should be chipped nnder with a center chisel in soveral places in order to hold the babbit well. Then take a parallel pieco of iron largo enough to cover tbe hole, and perfectly smooth on one surface, place a little oil on the smooth surface and press the piece of glass to it. By this means you exclude the air, and the glass and iron will stick together firmly; this is done in order to hold tbe glass up from the bottom of the hole, and thus allow the babbit to run under as well as around it, forming a perfect bed for the glass to rest on. Place the piece of iron with the glass fast to it over the hole}in such a manner as to keep the glass in the centor, and also leave a small space uncovered through which to pour the babbit. The glass should be above the surface of the working part, in order to take the full bearing. Place at least one thickness of writing paper between the parallel piece and the other surface; clamp the parallel piece to the gibb or other part, for if not clamped the glass is likely to rise too high above the surface while the habbit is being poured. Caulk the babbit in several places with a blunt center-punch between the glass and iron, theu scrape it down to tho surface. Bearings put iu locomotive cross-heads should not be more than flush with the surface. To insert tho bearings in cylinder packingrings, eccentrics, etc., a groove should be cast or turned in the center of sufficient depth and width to allow the babbit to run under and around the glass; the groove should be turned nnder and also chipped rough on the sides, Then bend a strip of sheet-iron to the exact radius, and make the proper surface smooth, then stick five or six pieces of glass to the smooth surface by means of putty or any other substance that will stick well. Then clamp the sheet iron with the glass fast to it to the ring or other part; close up one end with putty, and pour the babbit inthe other end. When the plass is all inserted, take oil and emery with a file and grind the glass down to the surface, making sure that not one of the glasses are above the surface when the ring is finished. In parts where there is not sufficient thickness of material to allow the babbitt metal to he run under the glass, one thickness of muslin may be used as a bed for the glass to rest upon.” These bearings are now very exteusively used in locomotives and stationary engines, and the manufacturer is furnishing them to all parts of the country and for all kinds of steam-machinery. Most persons, we believe, would be surprised to find how much rough nsage a piece of glass will bear if properly embedded in a soft metal. If they are well fitted they will stand a considerable number of quite severe blows from a hammer without being fractured. THE manager of a furnace in Prussia, fiuding himself without fuel, resolved to kcep the fnrnace alive as hest he might. He hegan at once to reduce the charge of iron ore to onehalf, keeping all the whlle the nsual charge of coke, and after the furnace was thus filled, the blast was cut off, and all apertures were closed as air-tight as possible, and watched carefully so for more than ninety days anxiety. A regular supply of fuel being once more secured,

after that time, the tuyers, hearth, and top wero reopened, the hot blast let on, and twelve hours later the first clean cinder made its appearance, flowing over the wall-stone, to the great delight of all concerned. A Prussian engineer has, it is aaid, invented a machine which will manufacture ice withont chemicals, merely by compression and explosion of air, ng f HCIENTIFIC Progress. Tue Speernoscore ox tne Nesutar HyrotuEsis,—Tho existence of immense nebulous masses, from which Laplace snpposed the solar system to have heen derived, was thought to have been proved basclees by the iucrcased power of modern telescopes, which havo resolved into clusters of stars many objects supposed to have been nebule. But since the spectroscope has been so improved as to he practically employed for determining the character of such distant bodies, the nvbulous thoory is again coming into favor, if indeed it may not now he considered as fully established on a stronger foundation than ever hefore. Prof. Kirkwood has made oxtended ohservations in this direction, in which the evidence in favor of the hypothosis is decidedly cumulative. Even progressive changes in the physical condition of eome of the aebulm have heen quite clearly indicated. In some parts of certain nebulw nuclei have been established—the mass of gaseons matter evidently passing from ite attenuated form into a semi-solid state. The speetra obtained prove this fact beyond the possibility of douht. This clasa of spectra reveals a constitution similar to that recently observed in certain comets belonging to onr own system. Vetociry or Mrreorre Srones.—It has been quite satisfactorily proven that meteors, before they meet with the retarding influence of the earth’s atmosphere, often move with a velocity several thonsand times that of a cannon ball at the instant of its discharge. If a cannon ball could be made to move with such velocity it would almost instantly be destroyed, and disappear ina streak of flame. It is probable, however, that the impetus necessary to impart such a velocity would at once reduce to powder any brittle substanco like cast iron or stone. Meteors which enter the atmosphere at any considerable angle from a direct line toward its center are deflected from their course and soon move from its influence. Such is no doubt the caso with many which are seen to flit across the sky; while many, if not most of those whicb enter in a direct line, are dissipated into impalpable gasses before they have passed half the distance from the solar bounds of the atmosphere to the earth, or reach the earth in a state of impalpable dust. Eruption oF MrrroritEs rrom TEE Sun.— The theory of a solar origin for meteorites, however strange and startling it may at first sight be, cau by no means be condemned as altogether illusory. Advocated by Mr. Proctor in Fraser’s Magazine, for April, 1871, much evidence in its favor has heen supplied by the recent solar researches of Secchi, Young and others. In brief, it is, that the solar prominences result from the shooting forth of liquid or solid masses orstreams of matter, and that metcoric masses, or at least some meteorites, may have originated in this manner, being propelled from beneath the surface of the sun. Mr. Runyard, in a recent communication to the Royal Astronomical Society, discussing the nature and origin of the upheaval of eruption prominences, states as his conclusion that the observed phenomena, and all other considerations, go far to render it probable that meteors are formed from the metallic vapors hurled from the sun or other stars, or that solid masses may be so hurled, in eruption prominences. Mr. F. A. Fleming also remarks of this theory, that, offering as it does a possible account of the genesis of prominences and meteorites, it appears also to contain the germ of another hypothesis, which he develops, respecting the cause of the connection between solar eruption and terrestrial magnetism. Tur Transtr or Venus.—Professor Henry and other scientific men connected with the Smithsonian Institute and the Naval Observatory haye nnitedin an interesting memorial to Congress urging the appropriation of $150,000 to make extensive and tborougb preparation for observing the transit of Venus across the sun, which will take place in 1874, which is looked upon as the most important astronomical event that has occurred for many years.’ The last transit was in 1792, and excited so much interest in the scientific world that seyoral European Governments made liberal appropriations to enable their astronomers to take observations. The transit of 1874 will not be visible in this country, and will be best seen from the islands of the South Pacific and Indian oceans. It is proposed to send naval expeditions to those points, accompanied by scientific parties. The Governmeuts of many of ,the conntries of Europe have already taken steps to this end, and there is little douht that Congress will enable the astronomers of this country to have the same advantages as their foreign hrethren. Tue proposed tunnel nnder Mt. St. Gothard will be ahout twice as long as the Mt. Cenis tunnel, andit will pass under peaks varying in hight from 8,750 feet to 10,000. The principal advantage anticipated from the work is an increase in the facilities for trade and travel between Europe and Asia, by way of Italy. Passtvirr or Inox, CapMivm, aNp Trx.—Many yeurs ago Faraday pointed out that when iron was plunged into nitric acid sufficiently concentrated, it became possessed of a surface condition which rendered it indifferent to the strongest acid; and which enahled it to form a voltaic circuit with ordinary iron. That such iron has really heen decidedly altered in character is also evinced hy the fact that it refuses to reduce copper from solution of its salts. Dr, Schin has observed that if cadmium is wrapped round with some platinum wire, it may be placed in strong nitric acid without being in tbe least degroe acted upou; but if tho wire is removed the cadmium is instantly attacked, thus showing that the passivity of the cadmium is entirely due to its contact with the platinum. The author also states that when tin is treated in a similar manner it exhibits ike pheuomena. Daxcrnovus Gas Prprs.— The Journal de UEclairage notices an accident which gives new proof of tho danger attending the uso of copper gas pipes. In April last, a workman haviag with a triangular tlle ent almost half through a gas-pipe of red copper 3% inch interior diameter, which supplied the Liege station, was removing the tool, when an explosion took place, with a noise like the report of a rifle, and the workman wae much burnt. A similar accident happened subsequently, hut with lessintensity, and the workman, who was not injured, did not report the circumstance. Some gas-pipes having heen taken down, they were found covered with a blackish coating, and they showed evident signs of corrosion from ammoniacal condensation. The hlack matter was analyzed, and was found to consist of acetylide of copper, which explodos between 203 deg. and 248 deg., producing water, copper, carbon, carbonic acid, and traces of carhonic oxide, Tue Esry Rar Tueory.—It is stated that notwithstanding the continued and wide-spread fires which prevailed for four or five weeks in Northern Illinois, last summer, devastating forests over a large area, not a drop of rain fell, as might have been expected, if the Espy rain theory is correct. The rain only came with a change of wind to northward, and seveee after the worst burnings were over witb. On the contrary, heavy rains followed immediately after the great firoin Chicago. Possibly the occurrence of rain in the latter instance was due to the greater intensity and concentration of heat. UNEXTINOUIsHABLE Sianat Lawp.—Some experiments have been made in Tamise, with the unextinguishable self-lighting signal lamp of Holmes, and they promise a great snccess. The lamp is a cylinder of tin, with a conical top; the cylinder is filled with phosphuret of calcium, prepared by the inventor. When the lamp is plunged in water, this quid, entering the cylinder, effects the decomposition of the phosphuret; phosphuretted hydrogen is disengaged in large quantity with vapor of phosphorus, takes fire spotaneously, and burns with a brilliant flame.—Les Mondes. Crzanstna Woor. From Burrs.—The wool is soaked in a bath containing 2 ibs. alum to every 10 ibs. of wool and to this sulphuric acid added untilthe bath marks 6 deg. B. In this bath the wool shonld remain until its appearance shows that the bath has had its effect, when it must be taken out and thoroughly drained. It is then subjected to the action of a brushing machine which removes all the burrs. THE GREENLAND Meteorites. — Professor Nordenskiold states that the masses of meteoric iron brought from Greenland by the recent Sweedish expcdition soem to have formed the principle masses of enormous meteoric fall of miocene date, extending over an area of some two hundred square miles, The iron appears tobe free from silicates. Professor Ramsey thinks the masses may be of tellurie origin. Aw Acoustic EXPERTIMENT.—Let a wide glass tube, open at both ends, he taken, and in thisa piece of fine wire gauze be pusbed up some little distance. If the gauze isnow heated to redness over an ordinary Bunsen burner, and then removed, it will shortly emit a shrill note, lasting from 5—10 seconds. The experiment we believe will be new to most of our readers, and has the merit of always going off. An EXPERIMENTAL Gas Worrs.—The Germau Society of Gas and Water Experts have under consideration a plan for establishing an experimeutal gas works, for the purpose of deciding various questions which may arise in the details of their profession, by actual experiment. The proposed plau, if adopted, will be upon a large scale, so asto reproduce, as faras possible, all the conditions met with in practice. Lancs Sun Spor.—Professor S. P. Langley of the Alleghany Observatory, has computed the area of one of the spots lately visible near the center of the sun’s disc, from careful measurement, and found it exceeded 2,300,000 square miles, which is more than ten times the entire area of the earth. Renova of spots made by sugar, from goods with delicate colors and much sizing. Thespot should be rubbed with a damp cloth, and then with a piece of fresh bread, which will remove the saccharine matter without affecting the color. Tue principal supply of bismuth is derived from Bolivia, but it has recently :been discoyered in Australia.