Volume 15 (1867) (424 pages)

‘Tie Mining and Scientific Press. (19 Mechanical. Cettinc Gusss cypEr WatTEeR wiTH Spears —The London Photographic News gives the following hints and instructions relative to a mode of cutting glass with a common pair of scissors, which may not be known to the majority of our readers, and in places where glazier’s diamonds are not accessible, the process may he of some value. It requires a little patience and some dexterity to thus cut glass to a giveu line with asmooth edge, yet it can he done uuder water after a few careful trials. To mechanics and others who often have occasion to cut glass into peculiar shapes, it may he worth while to remember this simplo application. The operation is detailed as follows: r@In order to insure success, two points must bo attended to; first and most important, tho glass must he quite level whiletho keissors are applicd ; aud second, it is better to begin the eutting by taking otf small pieecs at the corners and along the edges, and so reduce the shape gradually to that required, for if auy attempt is made to cut the glass allat once. to the shupo, as we should cut a piece of cardhoard, it will most likely break just whero it is not wanted. Some kinds of glass cut much better than others; the softer glasses cut hest. The scissors need not be at all sharp, as their action does not depend much upon the state of the odgo presented to the glass. When the operation goes on well; the glass hreaks away from the scissors in small pieces in a straight line with the blades. This method has often proved very useful in cutting ovals, ete., which would he very expensive if ground out; and though the edges are not, so smooth as may he desired for some purposes, the method is worth knowing. New Uses ror Mica.—Puscher, of Nuremherg, latoly suggested tho use of mica for various decorative purposes. For one such application, the thin plates are first purified hy treatment with strong sulphuric acid, aud then silvered by the ordinary process adopted with looking glass. ‘The mica thus acquires a heautiful silver Inster, and it may easily he ent into auy shape to he used for inlaying work. The flexihility of the mica, will, of course, allow of its heing applied to round surfaces. When a shect of mica is heated to full redness for a time in aclay mufiio, it loses most ofits flexibility, and is changed considerahly in appearance. Under reflected light it has a dead silverwhite look, but viewed hy transmitted light it is seen covered with grey spots. This latter appearance is lost when two or three pieces are superposed, and the transparency is lost. The mica after heating is also a beautiful material for inlaying work. It should he cut into the shapes required hefore itis heated. Another very pretty effect is ohtained by scattering small fragments of mica on freshly-poured sheets of gelatine, and varnishing it with a dark-colored solution of gelatine, Finely ground mica on colored gelatine also shows very pretty effects; and the very finely-ground material mixed with a solution of gnm-arabic may he used, Puscher says, for silver iuk.—Jech. Magazine. CrYSTALLIZED BY ConcussioN.—A_ eircunistance apparently coufirmatory of the disputed theory of a molecnlar change in iron from mechanical shocks, is related by a correspondent at Underhill, Vt. He says that an old relic of the Revolution, a French gun harrel, which had been refitted with new stocks and locks several times, after standing fire perhaps the millionth time, } burst, and in such a mauner that every one who saw it pronounced it to have been originally a east iron barrel, until au old iron maker convinced them hy showing the weld on the under side. But the appearance otherwise was exactly like cast iron, and brittle at that. My. E. attrihuted the change in the iron to the action of the sulphur in tho powder and its long use and many times repeated action. Cemenr.—A cement particularly adapted for attaching the brass work to petroleum lamps, is made hy Puscher, hy hoiling three parts resin with one of caustic soda and five of water. The composition is then mixed with half its weight of plaster of paris, and sots firmly iu half to three-quarters of an hour. It is said to he of great adhesive power, uot permeahle to petroleum, a low conductor of heat, and hut superficially attacked by hot water. Zine white, white lezd or precipitated chalk may he suhstituted for plaster, but hardons more slowly. PersErvina Lismrr.—Mnieh attention is now heing paid in tho Eastern States to preparing Inmher, so as to make it moro durable than in its nutural state, The importance of sonie process for preserving lumber, in its great variety of uses and exposure to the destructive action of moisture, heat, and imperfect ventilation, has long heen recognized, and a successful and cconomical means to this end has heen found in the process of ‘‘Burnettizing.” That husiness is carried on in Bangor, Mainc, on a very extensivo scale. The material used is chloride of zinc, which, it is claimed, preserves wood from the adherence of animal and vegetahle parasites, and from the attacks of insects ; and also completely preserves it from wet and diy rot, besides’ rendering it uninflammahle when used of a certain requisite strength. Its effect on canvas, cordage, metals, etc., is said to he equally beneficial ; and the claims of the proprietor of the Burnettizing Works are strengthened by testimonials from a vast numher of ship builders, railroad men, manufacturers, ete. Paper Pipes, Cisterxs anp Parus.—We have already alluded to tho introduction of paper pipes for eonducting water, and the advantages which they possess over those made of iron or lead. Large tanks and cisterns are now being made; also pails, etc. In making these articles, the paper, by a peenliar process, is laid in sheets over a mold. The same material is also heing used for the manufacture of sugar molds. The pails made from it are said to outlast galvanized iron, and to withstarid a very great degree of heat. They are not effected hy acids or other eorrosive suhstances, and are greatly in reqnest on shiphoard, and other places where severe usage is expected. The price is rather high, $1.50 in currency at wholesale in New York ; still it is thonght their greater durability render them cheaper in the end than either wood or irou. STEEL W1IRE.—The use of steel wire has heen greatly extended since it hecame known that a wire could he produced which comhined the advantages of lightness with hardness and extreme tenacity. It is now employed not only in the manufacture of needles, fish-hooks, springs, mnsic-springs, sinall tools, umbrella-frames, and crinolines, bat also for ropes and cable. Steel wire rope is now very generally used in the amines, hoth of this country and Europe, where the light weight of the ropeis of such importance hoth in respect to safety and economy ; also on railway engiues, aud for drawing plows where stationary steam power is used for preparing the soil. Large quautities have heen required during the last five years for suhmarine telegraphic cahles. Steel wire ropes are also used on canals for towing purposes. Some idea of the quantity of steel wire used may he formed from the fact that one establishment in Great Britian has made during the last year more than 30,000 miles of one size, No. 13, equal in diameter to .005 of an inch. Printrxe on Grass. — DeMothey, a Frenchman, has devised an ink and other preparations hy which he is enabled to print on glass, by means of rollers, similar to those used in ealico printing. After printing, the glass is subjected to heat, by which the picture is vitrified and permauently fixed in the glass. The colors are mixed with a silico-borate of potash and lead, as usual in painting in glass ; the composition being rendered plastic hy-rosin and turpentine. Tue largest hardware mannfactory in the . United States is located at New Haven, Conn, It employs 800 hands, and turns out 4,000 different kinds of articles, mostly, Yankee notions. The aunual value of its productions is estimated at from four to five millions of dollars. Kyanizine By Sreamu.—tIt is said that while it costs about ninety cents each to Kyanize railroad sleepers by steepiug them in the liquid—the process usually employed —the samething can he effected equally well by means of hot vapor, at. an expense not exceeding teri cents. A WHOLE WELDED nomeR from Dusseldorf is exhibited at the Paris Exhibition by Prussia, A steam dome'is welded upon the boiler, and so accurately and smoothly is the whole work done as to he hardly distinguishahle, superficially, from a casting. o Sciontific Miseetlany. Mextrxe Wrotont Inox.—Many people, even well informed iron men, have an idea that wronght iron cannot he melted—that it will granulate and burn up, or oxidize in the furnace, rather than fuse. Such, how. ever, is not the case. Wrought iron may he melted and cast into molds, like ordinary east iron, provided a sufficient degree of heat is applied. Cast iron is fused at a temperature of 3,000°; hut wrought iron requires a degree of heat not less than 6,000° for fusion ; even if we could readily produce tho requisite degree of heut for melting wrought iron, where should we find the material sufliciently refractory to melt it in or retain it, as in a mold, while it was solidi. fying. Itis moro easily melted when sub_ jected to great heat in the presence of carbon and manganese. In tho process’ of the manufacturo of tho hest kinds of steel, wrought iron is cut up into small fragments, weighing four or five ounces each, placed iu a black lead crucible, with a little pulverized charcoal and black oxide of manganese. Thus prepared it is subjected to the requisite degree of heat, melted and run luto ingots, which are rolled or hammered into the desired shapes. Wrought iron is nearly a pure iron, and especially free from carhon; steel is a very pure cast iron—and like it, is a carhuret of iron; hence it can readily he melted. Wrought iron can be melted only after it has heen, again re-charged with the carhon of which it has heen deprived in the process of puddling, pressing, etc. For all practical purposes, therefore, wrought iron is infusible’ Drrixe py SUPERHEATED Steam.—Steam, wheu heated ahove 212°, hecomes more of an ahsorheut, and so increases as the heat is inereased. A room containing superheated steam hecomes a Turkish hath—that is, has a steam atmosphere, aud, proportionally, so far as the air is concerned, hecomes a vacuum. Fruit, lumher, ete., may he rapidly dried hy this process. A fruitdrying apparatus of this description is sold in New York, from two or three dollars . upto almost any price, according to size, ete, . Lumber is dried hy this process. It is sim. ply placed on ears, and drawn slowly . through a drying room, until thoroughly dried. The drying may he effected in a few hours. So powerful is the action that a fonr-inch scantling may he so thoroughly dried as todestroy the grain ; yet, hy proper mauagement;-no damage is done, The wood ean he seasoned to auy required extent. Itis hy far the hest process for drying fruit. Fruit should be rapidly driod, as soon as ripe, and before its starch is converted into sugar. When so dried, it is much hetter in quality and appearance, and keeps much longer and better. Freezixe Guyerrmz.—According to the statement of Dr. W. S. Squire, a mass of glycerine (not nitro-glycerine), on freezing, leaves a small portion of the liquid still in 8 fluid state; on carefully draining this from that portion which has been congealed, the latter is much lighter in color than wHen liquid. The solid portiou is heavier than the remaining liquid, aud sinks in it. The liquid drainings cannot he solidified, even when exposed to a great degree of artificial cold in thé laboratory. At least Dy. Squire had not sneceeded in congealing it; it was simply rendered a little more viscid. Even a journey from London to Edinburg, giving it hoth percussion aud intense cold, did not freeze it, or in any way induce chrystallization. Puants Bur Atr.— Modern chemistry teaches us that plants consist almost entirely of condensed gas, and return after death to their natural elements. of mineral matter which they contain is represented in theashes which are left after combustion, . The small amouut. Decomposition sx Gaszous Currey: A. Grenet, of France, has made the remax kable discovery that certain bodies are decomposed hy the simple passago of a current of inert gas. For example, when a current of nitrogen, hydrogeu, or common air, is seut through a solution of the eurhonate of lime, of baryta, or of potash, carhonic acid is set free, while lime, or baryta or potash, is precipitated. The gases will disengage sulphuretted hydrogen from the sulphidrates of the alkaline sulphides, In hke manner eulphuric acid gas may he disengaged from sulphide solutions, aud acetic acid from acetates. Oxides of nitrogen are eliminated from nitrates at a temperature much lower than the temperature of decomposition. These salts emit acid very slowly in the same atmosphere, and a rapid current is supposed to simply increase this tendeucy to dissociation. Tre Cuotera.—The Freneh Academy of Sciences recently offered a prize of $20,000 for a satisfactory solntion of the nature of and remedy for the Asiatie cholera. Several essays have heen handed in, opened and examined; hut no one has heen considered worthy of the prize; although several havo heen thought to possess sufficient merit to entitle them to special awards, which have accordingly heen declared. This learned -hody thereby express the opinion that neither the nature of the Asiatic cholera is well understood ; nor has any reliahle and scientific course of treatment yet heen devised for its cure, : Rare CeLestian PHenomena.—A very interesting celestial phenomena will take place on the 2ist of August next—one the dike of which has occurred hut twice hefore in the records of history. The planet Jupiter will.on that day he seen unaccompanied hy either of her satellites for the space of fully two hours. Of her four moons, three will be invisible, on account of their passing simultaneously over the planet's disk, while the fourth will, at the same time, he immersed in the shadow of the planet. How to Keep Kerosene Lames Crran. Most people who use kerosene lamps have found great difficulty in keeping them clean The oil seems to creepup hy the wick and otherwise, and thus ont and over the outside of the lamp. The Scientific American suggests, as a remedy, to smear the edges of the lamp where the oil comes ever, with the whito of an egg, gum-arahic or any other convenient suhstance which is repulsive to the oil. Tue Procress oF APPLIED ScrENcE.—Industrial Exhihitions may he taken as the index of the extent of the practical applicatiou of scientifie principles. The international Fair at the Crystal Palace, London, 1851, displayed the prodnets of not quite 14,000 exhibitors, That at Paris in 1855 emhraced 24,000 exhihitors. That at London in 1862 contained 29,000. At the present Exposition at Paris there are no less than 45,000 exhihitors. Power or THE Sun’s Rays.—A lens has recently heen made for Mr. Parker, of Londou, three feet in diameter, three inches thickin the center, and weighing 212 pounds, In the focus of this powerful lens the most refractory metals are almost instautly fused and completely dissipated in vapor, while unyielding stony suhstances are as readily vitrified. ’ ; ee Conversation By TELEGRAPH.—A remarkable discovery is reported in Italy, hy which itis claimed that two persons ata distance may converse by telegraph, so that they may recognize each other’s voices. The modus operandi has not been made publie, and for the lack of it the asserted inventiou is considered very doubtful. Weear has heen subjected to a temperature of 100 degrees helow zero, and to a temperature of 210 degrees above zero, without destroying its germinating properties, Coan vs. Woop.—It is stated in the N. Y. Gas-Light Journal, that while a ton of coal yields hut 11,000 feet of gas, a cord of wood has been made to yield 98,000 feet.

‘Tie Mining and Scientific Press. (19 Mechanical. Cettinc Gusss cypEr WatTEeR wiTH Spears —The London Photographic News gives the following hints and instructions relative to a mode of cutting glass with a common pair of scissors, which may not be known to the majority of our readers, and in places where glazier’s diamonds are not accessible, the process may he of some value. It requires a little patience and some dexterity to thus cut glass to a giveu line with asmooth edge, yet it can he done uuder water after a few careful trials. To mechanics and others who often have occasion to cut glass into peculiar shapes, it may he worth while to remember this simplo application. The operation is detailed as follows: r@In order to insure success, two points must bo attended to; first and most important, tho glass must he quite level whiletho keissors are applicd ; aud second, it is better to begin the eutting by taking otf small pieecs at the corners and along the edges, and so reduce the shape gradually to that required, for if auy attempt is made to cut the glass allat once. to the shupo, as we should cut a piece of cardhoard, it will most likely break just whero it is not wanted. Some kinds of glass cut much better than others; the softer glasses cut hest. The scissors need not be at all sharp, as their action does not depend much upon the state of the odgo presented to the glass. When the operation goes on well; the glass hreaks away from the scissors in small pieces in a straight line with the blades. This method has often proved very useful in cutting ovals, ete., which would he very expensive if ground out; and though the edges are not, so smooth as may he desired for some purposes, the method is worth knowing. New Uses ror Mica.—Puscher, of Nuremherg, latoly suggested tho use of mica for various decorative purposes. For one such application, the thin plates are first purified hy treatment with strong sulphuric acid, aud then silvered by the ordinary process adopted with looking glass. ‘The mica thus acquires a heautiful silver Inster, and it may easily he ent into auy shape to he used for inlaying work. The flexihility of the mica, will, of course, allow of its heing applied to round surfaces. When a shect of mica is heated to full redness for a time in aclay mufiio, it loses most ofits flexibility, and is changed considerahly in appearance. Under reflected light it has a dead silverwhite look, but viewed hy transmitted light it is seen covered with grey spots. This latter appearance is lost when two or three pieces are superposed, and the transparency is lost. The mica after heating is also a beautiful material for inlaying work. It should he cut into the shapes required hefore itis heated. Another very pretty effect is ohtained by scattering small fragments of mica on freshly-poured sheets of gelatine, and varnishing it with a dark-colored solution of gelatine, Finely ground mica on colored gelatine also shows very pretty effects; and the very finely-ground material mixed with a solution of gnm-arabic may he used, Puscher says, for silver iuk.—Jech. Magazine. CrYSTALLIZED BY ConcussioN.—A_ eircunistance apparently coufirmatory of the disputed theory of a molecnlar change in iron from mechanical shocks, is related by a correspondent at Underhill, Vt. He says that an old relic of the Revolution, a French gun harrel, which had been refitted with new stocks and locks several times, after standing fire perhaps the millionth time, } burst, and in such a mauner that every one who saw it pronounced it to have been originally a east iron barrel, until au old iron maker convinced them hy showing the weld on the under side. But the appearance otherwise was exactly like cast iron, and brittle at that. My. E. attrihuted the change in the iron to the action of the sulphur in tho powder and its long use and many times repeated action. Cemenr.—A cement particularly adapted for attaching the brass work to petroleum lamps, is made hy Puscher, hy hoiling three parts resin with one of caustic soda and five of water. The composition is then mixed with half its weight of plaster of paris, and sots firmly iu half to three-quarters of an hour. It is said to he of great adhesive power, uot permeahle to petroleum, a low conductor of heat, and hut superficially attacked by hot water. Zine white, white lezd or precipitated chalk may he suhstituted for plaster, but hardons more slowly. PersErvina Lismrr.—Mnieh attention is now heing paid in tho Eastern States to preparing Inmher, so as to make it moro durable than in its nutural state, The importance of sonie process for preserving lumber, in its great variety of uses and exposure to the destructive action of moisture, heat, and imperfect ventilation, has long heen recognized, and a successful and cconomical means to this end has heen found in the process of ‘‘Burnettizing.” That husiness is carried on in Bangor, Mainc, on a very extensivo scale. The material used is chloride of zinc, which, it is claimed, preserves wood from the adherence of animal and vegetahle parasites, and from the attacks of insects ; and also completely preserves it from wet and diy rot, besides’ rendering it uninflammahle when used of a certain requisite strength. Its effect on canvas, cordage, metals, etc., is said to he equally beneficial ; and the claims of the proprietor of the Burnettizing Works are strengthened by testimonials from a vast numher of ship builders, railroad men, manufacturers, ete. Paper Pipes, Cisterxs anp Parus.—We have already alluded to tho introduction of paper pipes for eonducting water, and the advantages which they possess over those made of iron or lead. Large tanks and cisterns are now being made; also pails, etc. In making these articles, the paper, by a peenliar process, is laid in sheets over a mold. The same material is also heing used for the manufacture of sugar molds. The pails made from it are said to outlast galvanized iron, and to withstarid a very great degree of heat. They are not effected hy acids or other eorrosive suhstances, and are greatly in reqnest on shiphoard, and other places where severe usage is expected. The price is rather high, $1.50 in currency at wholesale in New York ; still it is thonght their greater durability render them cheaper in the end than either wood or irou. STEEL W1IRE.—The use of steel wire has heen greatly extended since it hecame known that a wire could he produced which comhined the advantages of lightness with hardness and extreme tenacity. It is now employed not only in the manufacture of needles, fish-hooks, springs, mnsic-springs, sinall tools, umbrella-frames, and crinolines, bat also for ropes and cable. Steel wire rope is now very generally used in the amines, hoth of this country and Europe, where the light weight of the ropeis of such importance hoth in respect to safety and economy ; also on railway engiues, aud for drawing plows where stationary steam power is used for preparing the soil. Large quautities have heen required during the last five years for suhmarine telegraphic cahles. Steel wire ropes are also used on canals for towing purposes. Some idea of the quantity of steel wire used may he formed from the fact that one establishment in Great Britian has made during the last year more than 30,000 miles of one size, No. 13, equal in diameter to .005 of an inch. Printrxe on Grass. — DeMothey, a Frenchman, has devised an ink and other preparations hy which he is enabled to print on glass, by means of rollers, similar to those used in ealico printing. After printing, the glass is subjected to heat, by which the picture is vitrified and permauently fixed in the glass. The colors are mixed with a silico-borate of potash and lead, as usual in painting in glass ; the composition being rendered plastic hy-rosin and turpentine. Tue largest hardware mannfactory in the . United States is located at New Haven, Conn, It employs 800 hands, and turns out 4,000 different kinds of articles, mostly, Yankee notions. The aunual value of its productions is estimated at from four to five millions of dollars. Kyanizine By Sreamu.—tIt is said that while it costs about ninety cents each to Kyanize railroad sleepers by steepiug them in the liquid—the process usually employed

—the samething can he effected equally well by means of hot vapor, at. an expense not exceeding teri cents. A WHOLE WELDED nomeR from Dusseldorf is exhibited at the Paris Exhibition by Prussia, A steam dome'is welded upon the boiler, and so accurately and smoothly is the whole work done as to he hardly distinguishahle, superficially, from a casting. o Sciontific Miseetlany. Mextrxe Wrotont Inox.—Many people, even well informed iron men, have an idea that wronght iron cannot he melted—that it will granulate and burn up, or oxidize in the furnace, rather than fuse. Such, how. ever, is not the case. Wrought iron may he melted and cast into molds, like ordinary east iron, provided a sufficient degree of heat is applied. Cast iron is fused at a temperature of 3,000°; hut wrought iron requires a degree of heat not less than 6,000° for fusion ; even if we could readily produce tho requisite degree of heut for melting wrought iron, where should we find the material sufliciently refractory to melt it in or retain it, as in a mold, while it was solidi. fying. Itis moro easily melted when sub_ jected to great heat in the presence of carbon and manganese. In tho process’ of the manufacturo of tho hest kinds of steel, wrought iron is cut up into small fragments, weighing four or five ounces each, placed iu a black lead crucible, with a little pulverized charcoal and black oxide of manganese. Thus prepared it is subjected to the requisite degree of heat, melted and run luto ingots, which are rolled or hammered into the desired shapes. Wrought iron is nearly a pure iron, and especially free from carhon; steel is a very pure cast iron—and like it, is a carhuret of iron; hence it can readily he melted. Wrought iron can be melted only after it has heen, again re-charged with the carhon of which it has heen deprived in the process of puddling, pressing, etc. For all practical purposes, therefore, wrought iron is infusible’ Drrixe py SUPERHEATED Steam.—Steam, wheu heated ahove 212°, hecomes more of an ahsorheut, and so increases as the heat is inereased. A room containing superheated steam hecomes a Turkish hath—that is, has a steam atmosphere, aud, proportionally, so far as the air is concerned, hecomes a vacuum. Fruit, lumher, ete., may he rapidly dried hy this process. A fruitdrying apparatus of this description is sold in New York, from two or three dollars . upto almost any price, according to size, ete, . Lumber is dried hy this process. It is sim. ply placed on ears, and drawn slowly . through a drying room, until thoroughly dried. The drying may he effected in a few hours. So powerful is the action that a fonr-inch scantling may he so thoroughly dried as todestroy the grain ; yet, hy proper mauagement;-no damage is done, The wood ean he seasoned to auy required extent. Itis hy far the hest process for drying fruit. Fruit should be rapidly driod, as soon as ripe, and before its starch is converted into sugar. When so dried, it is much hetter in quality and appearance, and keeps much longer and better. Freezixe Guyerrmz.—According to the statement of Dr. W. S. Squire, a mass of glycerine (not nitro-glycerine), on freezing, leaves a small portion of the liquid still in 8 fluid state; on carefully draining this from that portion which has been congealed, the latter is much lighter in color than wHen liquid. The solid portiou is heavier than the remaining liquid, aud sinks in it. The liquid drainings cannot he solidified, even when exposed to a great degree of artificial cold in thé laboratory. At least Dy. Squire had not sneceeded in congealing it; it was simply rendered a little more viscid. Even a journey from London to Edinburg, giving it hoth percussion aud intense cold, did not freeze it, or in any way induce chrystallization. Puants Bur Atr.— Modern chemistry teaches us that plants consist almost entirely of condensed gas, and return after death to their natural elements. of mineral matter which they contain is represented in theashes which are left after combustion, . The small amouut. Decomposition sx Gaszous Currey: A. Grenet, of France, has made the remax kable discovery that certain bodies are decomposed hy the simple passago of a current of inert gas. For example, when a current of nitrogen, hydrogeu, or common air, is seut through a solution of the eurhonate of lime, of baryta, or of potash, carhonic acid is set free, while lime, or baryta or potash, is precipitated. The gases will disengage sulphuretted hydrogen from the sulphidrates of the alkaline sulphides, In hke manner eulphuric acid gas may he disengaged from sulphide solutions, aud acetic acid from acetates. Oxides of nitrogen are eliminated from nitrates at a temperature much lower than the temperature of decomposition. These salts emit acid very slowly in the same atmosphere, and a rapid current is supposed to simply increase this tendeucy to dissociation. Tre Cuotera.—The Freneh Academy of Sciences recently offered a prize of $20,000 for a satisfactory solntion of the nature of and remedy for the Asiatie cholera. Several essays have heen handed in, opened and examined; hut no one has heen considered worthy of the prize; although several havo heen thought to possess sufficient merit to entitle them to special awards, which have accordingly heen declared. This learned -hody thereby express the opinion that neither the nature of the Asiatic cholera is well understood ; nor has any reliahle and scientific course of treatment yet heen devised for its cure, : Rare CeLestian PHenomena.—A very interesting celestial phenomena will take place on the 2ist of August next—one the dike of which has occurred hut twice hefore in the records of history. The planet Jupiter will.on that day he seen unaccompanied hy either of her satellites for the space of fully two hours. Of her four moons, three will be invisible, on account of their passing simultaneously over the planet's disk, while the fourth will, at the same time, he immersed in the shadow of the planet. How to Keep Kerosene Lames Crran. Most people who use kerosene lamps have found great difficulty in keeping them clean The oil seems to creepup hy the wick and otherwise, and thus ont and over the outside of the lamp. The Scientific American suggests, as a remedy, to smear the edges of the lamp where the oil comes ever, with the whito of an egg, gum-arahic or any other convenient suhstance which is repulsive to the oil. Tue Procress oF APPLIED ScrENcE.—Industrial Exhihitions may he taken as the index of the extent of the practical applicatiou of scientifie principles. The international Fair at the Crystal Palace, London, 1851, displayed the prodnets of not quite 14,000 exhibitors, That at Paris in 1855 emhraced 24,000 exhihitors. That at London in 1862 contained 29,000. At the present Exposition at Paris there are no less than 45,000 exhihitors. Power or THE Sun’s Rays.—A lens has recently heen made for Mr. Parker, of Londou, three feet in diameter, three inches thickin the center, and weighing 212 pounds, In the focus of this powerful lens the most refractory metals are almost instautly fused and completely dissipated in vapor, while unyielding stony suhstances are as readily vitrified. ’ ; ee Conversation By TELEGRAPH.—A remarkable discovery is reported in Italy, hy which itis claimed that two persons ata distance may converse by telegraph, so that they may recognize each other’s voices. The modus operandi has not been made publie, and for the lack of it the asserted inventiou is considered very doubtful. Weear has heen subjected to a temperature of 100 degrees helow zero, and to a temperature of 210 degrees above zero, without destroying its germinating properties, Coan vs. Woop.—It is stated in the N. Y. Gas-Light Journal, that while a ton of coal yields hut 11,000 feet of gas, a cord of wood has been made to yield 98,000 feet.