Volume 18 (1869) (430 pages)

The Mining and Scientific Press. 99 Mechanical, Rove-Borina a CrHinese INVENTION. — Mr. Warrington Smyth, in a recent lecture at the Royal School of Mines, said: ‘* A plan of boring now much cimployed, and which we owe to the Chinese, is that with ropes instead of rigid rods. Freneh missionaries in the 17th century had observed that the Chinese had methods of boring to enormous depths. Tather Imbert, having made a communication to the Prench Academy, to the effect that the Chincse borers had attained a depth of 3,000 feet, the statement was discredited. Eventually travelers established the fact; and now itis a matter ef discussion whether it is uota methed which will compare well with any of the more modern ones. The ropes used by the Chinese are made of strips of bamhoo, and those of England are tho ordinary hempen er wire-ropes. In cousequerice of the greater elasticity of ropes, it becomes necessary to give a longer stroke at the top, so that for a stroke of ten feet at the bottom it is necessary to give one of twenty feet at the top. The tool nsed ranges from,3 ewts. to half aton. The Chineso employ either eur comnton spring pole, or a rope passed round an enormous cyliuder fifty fect in diameter. It was by means of this cylinder that the missionarics ascertaincd the depth of the bovings. They took the cirenmfercuco of the drum, and found that the rope went sixty-two times around it. This method of boring secms to possess such advantages that at first sight it seems wonderful that it is not universally employed, but if has many drawhacks. Among these are the occasional breaking of the rope, and the consequent impossibility ef withdrawing the tool,—and the difficulty of preserving the perpendicu~ larity of the hole, in caso of a change in the hardness of the beds which are passed through.” Lupricatina O1ns,—Pease’s Oil Circular says first-class oils are more in demand. From 30 to 50 per cent. of power is lost for lack of knowledge in reference to the laws of friction and the effects of heat and pressure upon the oils used. Thousands of -of dollars are annually saved by those railrosd managers who give the subject proper ‘attention. ‘‘ There is no occasion for a hot journal on any road under ordinary circumstances, if proper oils are used. There is no occasion for cutting of journals and destruction of valve-seats, if a little thougbt would only be give to the subject. The wonderful chemical effect of some of tbe poor cheap oils upon the iron surfaces and journals of some of the roads is often overlooked. Has it ever occurred to rsilroad -men that the use of oils of strong acid renection has a teudency to weaken the strength of the boiler itself, as they have the power to cutand destroy the bolts of the steam chest and cylinder?” Buast Pirees.—The diameter and position of the pipe, the diameter of tbe chimney, nnd the size of the fire-box, tubes and smoke-box, are all concerned in the effect produced. According to investigations by Mr. D. K. Clark and otbers, it has been shown that tbe vacuum in the smoke-box is ‘about seven-tentbs of the blast pressure; ‘that the vacuum in tbe fire-box is trom onethird to one-half that in the smoke-box; that the best proportions of the chimney and other parts are those which enablo a -given draught to be produced with the freatest diameter of blast-pipe, because the greater the diameter the less is the back pressure produced by the resistance of the orifice; and that the same proportions are best at all rates of expausiou and at all speeds, —American Artisun. Tas Srmsam Hasmmr.—The Trench claim the inventiou of the steam hammer for M. Mourdon, who took out a pateut in April, 1842,—-whereas Mr. Nasmyth, they say, did not take out his pateut in England until June of tbe same year;—having, moreover, visited the irou works of Le Crue sot, Burgundy, between these two mouths. Morton's Ejector ‘Condenser. The London Artizans for Janaary contains & paper recently read before the Tustitute of Scottish Engineers by Prof. Rankine, giving an account of experiments made by him with this condenser. We quote a portion: “The principal parts of the apparatus may be thns doseribed: The cold water passes from the tank to a convidal nozzle; tae arca of the orifice of that nozzle is about equal to that of the injection sluice of a commen condenser suited for the same cngine; that is to say, about 1-250th part of the collective area of pistons. Enveloping the cold water uozzlcs are a second and a third nozzle of nearly similar figure; these bring the exhaust steam from the two cylinders respectively. The middle uozzle has an orifice a little larger than that of the innermost, or cold water nozzle; the outermost nozzle ends in a throat or coutracted vein little larger still, beyond which is a gradually wideuing,trumpet-shaped mouthpiece, leading to a pipe which euds at tho hot-well. The condensation of the steam takes place in the interval between tho orifice of the cold water nozzle aud the throat of the outermost nozzle. “The principlo of the inveution may be descrihed as follows: In every injection condenser the cold water rnshes into the vacunm with a velocity of 43 or 44 feet per sccond,. Tho exhaust stcam rushes from the cylinders into the coudenser with a velocity which is many times greater than that of the water. In the common conSclentlfic Miscellany. “Chemical Geology of California Gold Fields. Sillinan's Journal for January, las an abstract of J. Arthur Phillip’s *‘ Notes” upon this subject. The general conclusions of the antlor are here giveu: a, Quartz veins have generally been produevd hy the slow deposition from aqucous solutions of silica on the surfaces of the enclosing fissures. 6, From the geners] parallelisns witli its walls of the planes of any fragments of the enclosiug rock which uwy have heeome imbedded in a vein, it is to be inferred that they were mechanically removed by the growth of the sevoral layers to which they adhered, und that asubsequent deposition of quartz took place between them and the rock from which they bad become detached. In this way were introduced the masses of rock known as “ horses,” e, The formation of quartz veins is due to hydrothermal agencies, of which evidences are still to be found in the hot springs and recent metalliferous veins met with in various parts of the Pacific coast. d. Fyrom the variable temperatures at which the vacuities in their fluid-cavities become filled, it may be inferredthat they are the result of an intermittent action, and that the fissures were sometimes traversed by currents of hot water, whilst at others they gsve off aqueous vapor or gaseous exdenser those rapid motions of the water snd .of the steam are completely checked, and their energy is wasted in agitating the fluids in the condenser, and ultimately in pro-. ducing heat; and henco it becomes necessary to nso an alr pump iu order to extract the water, air and uncondensed stcam from the condenser. The power expended in working a well-proportioned and well-constructed air puntp is knowu hy experiment to be equal to that which would overcome 2. back pressure on the steam piston of from ¥% to % lh. on each square inch of its area, . or on an average about 0°6 Ib. on the square juch; and that amount of power is lost through the wasting of the energy with which tbe jets of water and steam rush into tbe condenser. In the ejector condenser the motion of those jets meets with no interruption; and its energy is found to be sufficient, without any assistance from pumps, to carry all the water, air and uncondensed steam {if any) completely ont of the condenser and into the hot-well, and thus to save the power which would be required to drive an air pump.” Bronzing Iron Castryes.—The dclicate Berlin iron castings are bronzed for their hetter preservation against rust, by means of a peculiar paint, of which ferro-eyanide of copper forms the basis. When an article has been coated witb this paint, and before it is quite dry, if dusted over with copper bronze powder and allowed to dry thoroughly, the effect will be that of bright copper after being polished. A grcen bronze tint is produced by washing with a solution of acetate of copper. When perfectly dry, the higher psrts of tbe casting must be rubbed with a piece of clean rag to bring out the brown copper color; it will then appear like a bronze that has become green by age. If the bright coppercolored bronze above mentioned be brushed over with black lead it will produce the brown bronze. Yellow or pale bronze, is obtained by using yellow bronze, or brags powder, instead of copper powder. Tur First LocomorrveE in Amentca.— ‘The *‘ Old Ironsides,” built in Philadelphia in 1832, by M. Baldwin, from a draft by Rufus Tyler, had wooden wheels with broad rims and thick fires,—the flange being bolted on the side, She ran a mile an hour, The tender was placed in front, in order to keep the two light wheels of the engine on the track. The wheels finally went to pieces, ancl were replaced by iron ones, The engine is still in existence. Wire Rore.—At the Havre Exhibition, the wire rope of Scott & Co. was awarded halations. This is precisely what is now taking place at Stoambost Spriugs, where tbe formation of a vein is in progiess, and from which currents of boiling water are often poured forth, whilst at other times the fissures give off currents of steam and heated gases only. e, That gold may be deposited from the same solutious which gave rise to the forniation of the enclosing quartz, appears evident from the presence of that metal in pyrites enclosed in silicious incrustations, as well as from the fact of large quantities of gold having been found in the interior of the stems of trecs, wbich in deep diggings are often converted into pyrites, J. The constant presence of iron pyrites in auriferous veins, and wheu so occurring its invariably containing a certain amount of gold, suggests the probability of this sulphid being in some way necessarily connected witb the solvent by which the precious metal was beld in solution. It has been shown that finely divided gold is soluble in the sesquichloride of iron and, more sparingly, in tbe sesquisulphate of that metal. It is also well known that iron pyrites sometimes results from the action of tedncing agents on the sulphates of that métal. If, therefore, sulphate of iron, in a solution contsining gold, should become transformed by the action of a reducing agent into pytites, tbe gold at the same time being reduced to tbe metallic state, would prohably be found enclosed in the resulting crystals of that mineral. g. The silica and other substances forming the cementing material of tbe ancient auriferous river beds bave probably been slowly deposited at a low temperature, To Detect ATMosPpHERIO AIR IN COAL Gas.—Dr, Werner, of Breslau, gives the following method: Ten parts by weight of anhydrous sulphate of protoxide of manganese are put into a two-necked Woulf battle, dissolved in tweuty parts of warm water. To this is added a solution of ten parts by weight of tartrate of potassa and soda (Rochelle salt), dissolved in sixty parts of water; the thorough mixing of the fluids is promoted by shaking of the bottle; after this there is added a quantity of a solution of caustic potash suflicient to render the fluid quite clear; immediately after this corks, perforated with tightly-fitting glass tuhes, are placed in the necks of the bottle, which should be entirely filled with the fluid. One of tho tubes—the inlet-tube for the gas to be tested—should just dip a little under the npper level of the flnid; the outlet tube should only reach half-way the perforation of tbe cork. A very slow current of gas is now made to pass through the finid, and kept going for at least a quarter andat most one full hour. In case the gas is quite free from atmospheric air, the fluid the prize medal. ‘A piece of 4-inch steel wire rope stood the enormous strain of forty tons, and slipped through the splice without breaking,”—says 2 London corres: pondent. in the bottle will remain quite clear; if traces of air are present, a faint coloration of the liquid will soon become apparent; ) with a larger proportion of air the fluid will soon be rendered. first light-brown colored, , aud afterward intensely black. Evouvrion oF tHE Nonta AMERICAN ConTINENT.—Wo condense a part of Prof. Hall's recent lecture upon this subject beforo the Americau Institute: “In the formation of the continent, the material composing it have been derived from the breaking down of preéxisting materials transported and deposited aloug cerfain lines, or spread ont in mid-oceau and there acconmlating uniformly. The ineqnalities upon the surface of the country are not due toany special action along tbeso lines of elevation. ‘Those mountain ran ges, whether the Rocky Mountains of the West, the Appalachian chain of the East, or any other chain of mountaius, so faras we know, are not due to any action or any forces along those lines, but only to the greater currents in the bed of the ocean near those lines. Everywhere the same law has prevailed, The transporting power of the occan has deposited in the line of its curronts larger quantities of material. “The elevation has been a continental one, and not the clevation of a mountain or chain of mountains, The elevation of the eastern portion of the North American Continent has nothing to do with the mountain chsnge constituting a portion of the continental elevation. Going hack, then, step by step, from the more recent to the earlicst times in relation to which we have any evidence whatever, we have no proof that the action of the interior of our globe has produced sny of the great features of tbe glohe. This idea of a grest primary nucleus is only theorétical. It has notin it anythiug tangible. The earliest rocks of whicb we have auy knowledge wero deposited by the ocean under conditions similar to thoso which now exist.” Tue Vouraio Anc.—The hluish space between the brilliantly incandescent charcoal points which give the electric light,—curved in form when the poiuts are in a horizontal line, owing to aiseending currents of heated air, and hence called the voltaic are,—is the route taken by the electric current in passing from oue of tbe poiuts to the other. What is its uature? It is carhon in some form, but what form? Fine dust, vapor or gas? In an articlé by F. P. Le Roux, in the Chemical News, the writer says that recent experiments of his have led to the belief that it is evolved from the positive pole; and that it is due toa special sonrec of heat at that point, hitberto unexplained. We qnote a portion of the srticle: ‘‘The positive charcoal is considerably more luminous than the other, and its incandescence of longer duration. I am even inclined to believe tbat the negative charcoal is heated almost entirely by the radiation of heat from tbegpsitive charcoal on one hand and the are on the other, and hy the heat proceeding from the condensation of the matter conveyed by the latter. I have made an experiment which will show that the heating of the positive 1 0’e is owing to a special cause, the seat of which is the exact point where the voltaic are joins the cbarcoal. Tbe experiment consists in this: Tbe charcoal electrodes are first brought into contact in the ordinary manner, and then separated so as to produce a very short are of only a small fraction of a millimeter, which is interrupted at the end of some seconds; the positive electrode will then be found to remain incandescent for some time, whilst the extremity of tho ‘negative electrode will be scarcely red.” GaLENA in THE LanonaTory.—M. EF. Muck states that crystallized cubes of galenu are obtained by the action of HS on hot solntions, strongly acid, of nitrate of lead, the hotter and mcre acid the better. Eveu solutions nearly nentral, if partislly precipitated, so asto render tbem acid, afterwards yield crystals. Precipitates from the acetate and cbloride of lead are wholly amorphous. Becquerel, de Seuarmont, Bischoff, Brush of Yale College, and others, have already obtained galena in the wet way. -It is stated that Flach. by placing a stick of brimstone in an alkaline solution of ‘oxide of lcad, obtained,— after some years,—deposits, both on the stick itself and on the walls of the vessel, covered witb small cubical erystals of galena, recygnizable without a magnifier.—Prof. Wurtz— Gas Light Journal, Soran Heat Utmazep.—Prof. Mouchot, of Tours, France, announces a work upon this subject, soou to be in press. In 1864, Prof. M. constructed a small steatu engine operated by means of a “‘solar boiler;” and he has since contrived various pieces of apparatus, on the same principle, for cooking, distilling, etc.

The Mining and Scientific Press. 99 Mechanical, Rove-Borina a CrHinese INVENTION. — Mr. Warrington Smyth, in a recent lecture at the Royal School of Mines, said: ‘* A plan of boring now much cimployed, and which we owe to the Chinese, is that with ropes instead of rigid rods. Freneh missionaries in the 17th century had observed that the Chinese had methods of boring to enormous depths. Tather Imbert, having made a communication to the Prench Academy, to the effect that the Chincse borers had attained a depth of 3,000 feet, the statement was discredited. Eventually travelers established the fact; and now itis a matter ef discussion whether it is uota methed which will compare well with any of the more modern ones. The ropes used by the Chinese are made of strips of bamhoo, and those of England are tho ordinary hempen er wire-ropes. In cousequerice of the greater elasticity of ropes, it becomes necessary to give a longer stroke at the top, so that for a stroke of ten feet at the bottom it is necessary to give one of twenty feet at the top. The tool nsed ranges from,3 ewts. to half aton. The Chineso employ either eur comnton spring pole, or a rope passed round an enormous cyliuder fifty fect in diameter. It was by means of this cylinder that the missionarics ascertaincd the depth of the bovings. They took the cirenmfercuco of the drum, and found that the rope went sixty-two times around it. This method of boring secms to possess such advantages that at first sight it seems wonderful that it is not universally employed, but if has many drawhacks. Among these are the occasional breaking of the rope, and the consequent impossibility ef withdrawing the tool,—and the difficulty of preserving the perpendicu~ larity of the hole, in caso of a change in the hardness of the beds which are passed through.” Lupricatina O1ns,—Pease’s Oil Circular says first-class oils are more in demand. From 30 to 50 per cent. of power is lost for lack of knowledge in reference to the laws of friction and the effects of heat and pressure upon the oils used. Thousands of -of dollars are annually saved by those railrosd managers who give the subject proper ‘attention. ‘‘ There is no occasion for a hot journal on any road under ordinary circumstances, if proper oils are used. There is no occasion for cutting of journals and destruction of valve-seats, if a little thougbt would only be give to the subject. The wonderful chemical effect of some of tbe poor cheap oils upon the iron surfaces and journals of some of the roads is often overlooked. Has it ever occurred to rsilroad -men that the use of oils of strong acid renection has a teudency to weaken the strength of the boiler itself, as they have the power to cutand destroy the bolts of the steam chest and cylinder?” Buast Pirees.—The diameter and position of the pipe, the diameter of tbe chimney, nnd the size of the fire-box, tubes and smoke-box, are all concerned in the effect produced. According to investigations by Mr. D. K. Clark and otbers, it has been shown that tbe vacuum in the smoke-box is ‘about seven-tentbs of the blast pressure; ‘that the vacuum in tbe fire-box is trom onethird to one-half that in the smoke-box; that the best proportions of the chimney and other parts are those which enablo a -given draught to be produced with the freatest diameter of blast-pipe, because the greater the diameter the less is the back pressure produced by the resistance of the orifice; and that the same proportions are best at all rates of expausiou and at all speeds, —American Artisun. Tas Srmsam Hasmmr.—The Trench claim the inventiou of the steam hammer for M. Mourdon, who took out a pateut in April, 1842,—-whereas Mr. Nasmyth, they say, did not take out his pateut in England until June of tbe same year;—having, moreover, visited the irou works of Le Crue sot, Burgundy, between these two mouths. Morton's Ejector ‘Condenser. The London Artizans for Janaary contains & paper recently read before the Tustitute of Scottish Engineers by Prof. Rankine, giving an account of experiments made by him with this condenser. We quote a portion: “The principal parts of the apparatus may be thns doseribed: The cold water passes from the tank to a convidal nozzle; tae arca of the orifice of that nozzle is about equal to that of the injection sluice of a commen condenser suited for the same cngine; that is to say, about 1-250th part of the collective area of pistons. Enveloping the cold water uozzlcs are a second and a third nozzle of nearly similar figure; these bring the exhaust steam from the two cylinders respectively. The middle uozzle has an orifice a little larger than that of the innermost, or cold water nozzle; the outermost nozzle ends in a throat or coutracted vein little larger still, beyond which is a gradually wideuing,trumpet-shaped mouthpiece, leading to a pipe which euds at tho hot-well. The condensation of the steam takes place in the interval between tho orifice of the cold water nozzle aud the throat of the outermost nozzle. “The principlo of the inveution may be descrihed as follows: In every injection condenser the cold water rnshes into the vacunm with a velocity of 43 or 44 feet per sccond,. Tho exhaust stcam rushes from the cylinders into the coudenser with a velocity which is many times greater than that of the water. In the common conSclentlfic Miscellany. “Chemical Geology of California Gold Fields. Sillinan's Journal for January, las an abstract of J. Arthur Phillip’s *‘ Notes” upon this subject. The general conclusions of the antlor are here giveu: a, Quartz veins have generally been produevd hy the slow deposition from aqucous solutions of silica on the surfaces of the enclosing fissures. 6, From the geners] parallelisns witli its walls of the planes of any fragments of the enclosiug rock which uwy have heeome imbedded in a vein, it is to be inferred that they were mechanically removed by the growth of the sevoral layers to which they adhered, und that asubsequent deposition of quartz took place between them and the rock from which they bad become detached. In this way were introduced the masses of rock known as “ horses,” e, The formation of quartz veins is due to hydrothermal agencies, of which evidences are still to be found in the hot springs and recent metalliferous veins met with in various parts of the Pacific coast. d. Fyrom the variable temperatures at which the vacuities in their fluid-cavities become filled, it may be inferredthat they are the result of an intermittent action, and that the fissures were sometimes traversed by currents of hot water, whilst at others they gsve off aqueous vapor or gaseous exdenser those rapid motions of the water snd .of the steam are completely checked, and their energy is wasted in agitating the fluids in the condenser, and ultimately in pro-. ducing heat; and henco it becomes necessary to nso an alr pump iu order to extract the water, air and uncondensed stcam from the condenser. The power expended in working a well-proportioned and well-constructed air puntp is knowu hy experiment to be equal to that which would overcome 2. back pressure on the steam piston of from ¥% to % lh. on each square inch of its area, . or on an average about 0°6 Ib. on the square juch; and that amount of power is lost through the wasting of the energy with which tbe jets of water and steam rush into tbe condenser. In the ejector condenser the motion of those jets meets with no interruption; and its energy is found to be sufficient, without any assistance from pumps, to carry all the water, air and uncondensed steam {if any) completely ont of the condenser and into the hot-well, and thus to save the power which would be required to drive an air pump.” Bronzing Iron Castryes.—The dclicate Berlin iron castings are bronzed for their hetter preservation against rust, by means of a peculiar paint, of which ferro-eyanide of copper forms the basis. When an article has been coated witb this paint, and before it is quite dry, if dusted over with copper bronze powder and allowed to dry thoroughly, the effect will be that of bright copper after being polished. A grcen bronze tint is produced by washing with a solution of acetate of copper. When perfectly dry, the higher psrts of tbe casting must be rubbed with a piece of clean rag to bring out the brown copper color; it will then appear like a bronze that has become green by age. If the bright coppercolored bronze above mentioned be brushed

over with black lead it will produce the brown bronze. Yellow or pale bronze, is obtained by using yellow bronze, or brags powder, instead of copper powder. Tur First LocomorrveE in Amentca.— ‘The *‘ Old Ironsides,” built in Philadelphia in 1832, by M. Baldwin, from a draft by Rufus Tyler, had wooden wheels with broad rims and thick fires,—the flange being bolted on the side, She ran a mile an hour, The tender was placed in front, in order to keep the two light wheels of the engine on the track. The wheels finally went to pieces, ancl were replaced by iron ones, The engine is still in existence. Wire Rore.—At the Havre Exhibition, the wire rope of Scott & Co. was awarded halations. This is precisely what is now taking place at Stoambost Spriugs, where tbe formation of a vein is in progiess, and from which currents of boiling water are often poured forth, whilst at other times the fissures give off currents of steam and heated gases only. e, That gold may be deposited from the same solutious which gave rise to the forniation of the enclosing quartz, appears evident from the presence of that metal in pyrites enclosed in silicious incrustations, as well as from the fact of large quantities of gold having been found in the interior of the stems of trecs, wbich in deep diggings are often converted into pyrites, J. The constant presence of iron pyrites in auriferous veins, and wheu so occurring its invariably containing a certain amount of gold, suggests the probability of this sulphid being in some way necessarily connected witb the solvent by which the precious metal was beld in solution. It has been shown that finely divided gold is soluble in the sesquichloride of iron and, more sparingly, in tbe sesquisulphate of that metal. It is also well known that iron pyrites sometimes results from the action of tedncing agents on the sulphates of that métal. If, therefore, sulphate of iron, in a solution contsining gold, should become transformed by the action of a reducing agent into pytites, tbe gold at the same time being reduced to tbe metallic state, would prohably be found enclosed in the resulting crystals of that mineral. g. The silica and other substances forming the cementing material of tbe ancient auriferous river beds bave probably been slowly deposited at a low temperature, To Detect ATMosPpHERIO AIR IN COAL Gas.—Dr, Werner, of Breslau, gives the following method: Ten parts by weight of anhydrous sulphate of protoxide of manganese are put into a two-necked Woulf battle, dissolved in tweuty parts of warm water. To this is added a solution of ten parts by weight of tartrate of potassa and soda (Rochelle salt), dissolved in sixty parts of water; the thorough mixing of the fluids is promoted by shaking of the bottle; after this there is added a quantity of a solution of caustic potash suflicient to render the fluid quite clear; immediately after this corks, perforated with tightly-fitting glass tuhes, are placed in the necks of the bottle, which should be entirely filled with the fluid. One of tho tubes—the inlet-tube for the gas to be tested—should just dip a little under the npper level of the flnid; the outlet tube should only reach half-way the perforation of tbe cork. A very slow current of gas is now made to pass through the finid, and kept going for at least a quarter andat most one full hour. In case the gas is quite free from atmospheric air, the fluid the prize medal. ‘A piece of 4-inch steel wire rope stood the enormous strain of forty tons, and slipped through the splice without breaking,”—says 2 London corres: pondent. in the bottle will remain quite clear; if traces of air are present, a faint coloration of the liquid will soon become apparent; ) with a larger proportion of air the fluid will soon be rendered. first light-brown colored, , aud afterward intensely black. Evouvrion oF tHE Nonta AMERICAN ConTINENT.—Wo condense a part of Prof. Hall's recent lecture upon this subject beforo the Americau Institute: “In the formation of the continent, the material composing it have been derived from the breaking down of preéxisting materials transported and deposited aloug cerfain lines, or spread ont in mid-oceau and there acconmlating uniformly. The ineqnalities upon the surface of the country are not due toany special action along tbeso lines of elevation. ‘Those mountain ran ges, whether the Rocky Mountains of the West, the Appalachian chain of the East, or any other chain of mountaius, so faras we know, are not due to any action or any forces along those lines, but only to the greater currents in the bed of the ocean near those lines. Everywhere the same law has prevailed, The transporting power of the occan has deposited in the line of its curronts larger quantities of material. “The elevation has been a continental one, and not the clevation of a mountain or chain of mountains, The elevation of the eastern portion of the North American Continent has nothing to do with the mountain chsnge constituting a portion of the continental elevation. Going hack, then, step by step, from the more recent to the earlicst times in relation to which we have any evidence whatever, we have no proof that the action of the interior of our globe has produced sny of the great features of tbe glohe. This idea of a grest primary nucleus is only theorétical. It has notin it anythiug tangible. The earliest rocks of whicb we have auy knowledge wero deposited by the ocean under conditions similar to thoso which now exist.” Tue Vouraio Anc.—The hluish space between the brilliantly incandescent charcoal points which give the electric light,—curved in form when the poiuts are in a horizontal line, owing to aiseending currents of heated air, and hence called the voltaic are,—is the route taken by the electric current in passing from oue of tbe poiuts to the other. What is its uature? It is carhon in some form, but what form? Fine dust, vapor or gas? In an articlé by F. P. Le Roux, in the Chemical News, the writer says that recent experiments of his have led to the belief that it is evolved from the positive pole; and that it is due toa special sonrec of heat at that point, hitberto unexplained. We qnote a portion of the srticle: ‘‘The positive charcoal is considerably more luminous than the other, and its incandescence of longer duration. I am even inclined to believe tbat the negative charcoal is heated almost entirely by the radiation of heat from tbegpsitive charcoal on one hand and the are on the other, and hy the heat proceeding from the condensation of the matter conveyed by the latter. I have made an experiment which will show that the heating of the positive 1 0’e is owing to a special cause, the seat of which is the exact point where the voltaic are joins the cbarcoal. Tbe experiment consists in this: Tbe charcoal electrodes are first brought into contact in the ordinary manner, and then separated so as to produce a very short are of only a small fraction of a millimeter, which is interrupted at the end of some seconds; the positive electrode will then be found to remain incandescent for some time, whilst the extremity of tho ‘negative electrode will be scarcely red.” GaLENA in THE LanonaTory.—M. EF. Muck states that crystallized cubes of galenu are obtained by the action of HS on hot solntions, strongly acid, of nitrate of lead, the hotter and mcre acid the better. Eveu solutions nearly nentral, if partislly precipitated, so asto render tbem acid, afterwards yield crystals. Precipitates from the acetate and cbloride of lead are wholly amorphous. Becquerel, de Seuarmont, Bischoff, Brush of Yale College, and others, have already obtained galena in the wet way. -It is stated that Flach. by placing a stick of brimstone in an alkaline solution of ‘oxide of lcad, obtained,— after some years,—deposits, both on the stick itself and on the walls of the vessel, covered witb small cubical erystals of galena, recygnizable without a magnifier.—Prof. Wurtz— Gas Light Journal, Soran Heat Utmazep.—Prof. Mouchot, of Tours, France, announces a work upon this subject, soou to be in press. In 1864, Prof. M. constructed a small steatu engine operated by means of a “‘solar boiler;” and he has since contrived various pieces of apparatus, on the same principle, for cooking, distilling, etc.