Volume 11 (1865) (424 pages)

The Hiining and Scientific Press. 295 *Wechanicat. Manufacturing and Tempering Sword-Blades An Important Pan Improvement. Tho Diamond Drill---Its History and a Deieee ————— ae in Indta. a ss scription of the Machine, Sta a SS — The Virghda Eaterpeise gives the blowing — BEFEOTS OF HEATING, ROLLING, HAMhe swonls uanufietural in the Regrury of deseviption nt the progess for mune inal . Pethane the most important provement ; : seceit hen, FERRE ve wit rR . Pa . ern 8 hee zd of Inte yeurs in the MERING, AND ANNEALING METALS. . een an "ali ve in ; a : s raunating ra a hie i we shuald suppose, might . jarportunt uml constantly increasing basiness Ch rave Ione been celebrated tu ledia for their) be"of muct vatne mul importatce : of rutting anil iressing stone, is the adopti ‘laborate exp? ta anil enreful ob-eren: . ae 7 on : ; Ba we UY LGUs Mis horate =p eS e a a wontlerful strength und enduring edge. The! We yesterday visited the new enameling . of the principie employed ip what is kuown ug tiene have devet ped) many poesia aie a fullowing dexeription of their mode of nimufac . furnace which bag jnst been cunatrneted ond is . tie Mandar Dhonond Drill, as mannfactared porta facts with regard ta. the variutie rc en roniatied w tho Hriicle pulticl about going mito eperntiat on UH street aur tis . by tue Sounbn Drill Cuipanys of this city. dencity, cle, which different inetals undergo ee ‘ ae city. “tlie Carnes, whiel is ct peenliar eon . Yorimay years the method ahnost oniversnlty in different degrees. in tho cperatinns of heutsome years siee, by oT English ariny officer Patrnetion. is the iuvention of Mr. Jota Han} employed to promnce troles ar ents in masses ‘ 1 i. a tan Reaiehiee aud, witnedtl who lil long held a amilitury command in that alone, aud the eusimel aypliect to the invention; of rock or ore, either in mining, blasting, quaring, drawing, rolling, meri al ing. “At a temperature rather nbove a cherry-red, icon wiro will remain three months, surronnded with charcoul.without cementation taking place, while a white heat will, in five miuutes, render brittle a sqnare bar of malleablo irou, eighttenths of un tach in diumeter. Wires of eapper, and of alloys of copper and ziae, ure increased in diainoter, and diminished jn density, by annealing. ‘Tho operation of rolling enndeases metals more thau thet of Wire-druwiug. ‘The density of iron and copper will be greater if the aetnis are heuted befors being passed through the rollers. ‘The reverss is the ease with alloys of copper and zinc. The deusity of metals is greatest. when drawa into very fing wires. Hence, two smull wires arg stronger thsu one largs one of the same transverse ares with the united areas of ths small ones. This result grows out of the fact that the particles of the smaller wires nre enmpacted throughout their entire eross: section, while those of the latter are thus eonipucted for o certnin depth oaly. : Wires may be increased in length in two wsys—first, by diniunition in the cnse of its ross seelion ; and second, but only in a slight degree, by increusiag the distanees between ths component particles. When wire is lengthened by the latter process, it returas to its former leagth hy annealfng. Again, wires of certain different metals, after psssing throngh the same hole in the wiredrawing plate, have different diameters ; but all such subsequently aequire equal diameters during the process of aanealiag. ‘lhe diameter of a wire is said to increase very slowly by time, after passing through a wire-drawing plate. Wires which have been bent, aad subsequently straightened, have a tendency to re-acquire the same curvature by time. Wires exposed toa high heat lose part of their tenacity. ‘Tey require to be anneuled in Wire-drawing, not to render them more tenacious, but to allow the particles to resume the positions from which they may again be displaced. The loss of tenacity is common to copper, iron, platiuum, and the alloys of copper and zine. Hydrogen has an action on copper and silver, at hich temperatures, which permaneatly separates their particles. Oa alloys of copper aud zinc, and even of silver and copper, it has no such actioa, Brass wire approaches to iron in strength, while copper wire is much inferior to it; hence, hrass is much used instead of iron where the latter would oxydize too rapidly. Troa wire is made of different qualities, to stand a strain from 75,000 up to 130,000 pounds to the square inch. The tenacity of brass iron varies from 78,000 to 87,000 pounds to the square iach ; while copper wire will part at from 38,000 to 44,000 pounds. These facts, with many others of a like character, have heea carefully arrived at by many and most elaborate experiments, aad a knowledge of them is valuable to every mechanic. —5 Oenrno’s Rervector.—This is the name of a new iavention just patented by John Oeding of this city, and designed as aa improvement oa the ordinsry kerosene lamp. It coasists of a simple lookiag-glass reflector, of any size desired, which is attuched to the lamp by a ring, aad placed at such an aagle as to reflect the light upon the proper place, at ths same time it sbades tbe eye from tbe blaze of the lamp. For writing, sewing, or other work requiring strong light, tbe reflector will be found very heneficial, while it can he afforded so cheap as . to be witbin the reach of all. . manufacturer in Horsforth, England, provinev, aud who had an opportunity of learning the prucess of matulacture und tempering employed in producing these wonderful blades : An inch bir of fius English or Swedish stecl is first foreed out into plates seven inclies long by one iuch broad, and one-sixth of nn inel thick. Similac bars of very fing sult iron wre then prepared in ths same manner. ‘These pieees of [urged steel snd irgn sre smeured over with # paste of horax, dissolved in water, and latd up in piles of between nine of steel Lo three of iron, ulternately; each pile is then wrapped arouud with thickly plastered ind, nade of a loamy earth; then heated, welded, and drawn out to aharol one ineh and oneeighth broad, and one-third of an inch thiek. Vhis is bent over upon itself three or lour times, and ngain welded and drawn ont to lulf nn iaeh in thickness, und duriag the heat borax is lrequently diopped on the wnetal while in the fire. ‘lwo or three burs of this metal thus prepared are next welded inty one, and when about twelve or fourteen inelies long, is bent into the form of a staple; in the middle of this piece x fine grained file is now inserted, of the same width aud nearly as thick as the bent bar; all is now welded toyether, nnd the blade then tormed. In tempering, an earthen pot, twelve inehes wide und six deep, is notehed on the edge, tle notehes being opposite to each other. The noteliing is.dune with a file,and about a quarter vt an inch deep. The pot is now filled nearly up to the notehes with water, and oil is then poured upon the surface. ‘Ihe sword-blide being heated eqnally to a light red leat, is removed from the fire, and the point entered iato the notch on oae edge is passed scross the surface of the oil and water to the opposite uoteh, keeping the edve from a quarter to half aainch iuthe oil; the blade is thus drawn backward and forsard rather slowly till the hissing ceases, and the rest of the blade above the fluid has beeyume black; ajng of water, without oil,is then poured alung the blade, lvom heel to point. In order to take out the warp produced by tempering, tlle blade, when aearly cold, is passed over the fire three or four times, then placed again upon the aavil, and set struight, bv strik ng it reeularly, but moderately, with the hammer. By this means a Damasens:eurved blade nay be brought uearly straight. Blades nade in this way are proved, previously to grinding, by striking them upon stones, ranirods, and gun-barrels. ‘Vhley may éven be struck violently upon wheel-tires, or heavy pieces of irun, without injury to the haninieied edge. Doty Arrreciaten.—We have several times had occasion to speak of the superiority of Hendy’s gang cirenlar saw-mills over the or. dinary saw-mill, both in the amount of work which it will turn off, and the manuer in which it turns its work out. T’be only mitl of this description yet in operatiou on this coast, is on Little River, Mendocino county. This mill recently turned out 32,500 feet of lumber in twelve hours. The eagine that ruus this mill is 14-inch bore and 18-inch stroke. The agent here says that the mill is not able to supply the demand, and oae of the mills is now being fitted up at Trinidad, Humboldt coanty, and will soon be sending its lumber into market. One million of feet are now oa hand ahead of the supply. This demand arises mainly from the superiority of the quality of the lumber which it produces. Ong of the most curious articles of an exhibition nos beiag held ia England, says the Chicago Journal, is a steam-engins and boiler, in miniature, and deseribed as the ‘ smallest steam-engine ia the world.” It stunds scarcely two inches in hight, and is covered with a glass shade. The fly-wheel is made of gold, with steel arms, and makes seven tbousand revolutioas per minute. The engiae and boiler are fasteaed together with thirty-eight miaiatore screws and bolts,the whole weighing fourteen grains, or under one-quarter of an ounce. ‘he manufacturer says that the ovaporation of one drop of water will drive the eagiae eight minutes. ‘bis dwarf piece of mechaaism ‘was designed and--‘made by a clack ‘ob Mir. Charles It, Golden. Buth thy furnnee aud the enamel are patented. ‘fhe material used forms on niuliers, pau bottums aud the sites of puns a cvatiine similar to the enamel on niamy iron kettles used for culinary purposes, thuigh unlike this the eontposition of the euainel we spruk of is such that it with-. stands the action of ull kinds of ecids. ‘The . enmnelis intended to be use in coating the) interior of puns usedin mills where the ores ure erushed dry and rousted. Jt uppears that where ores are thus treated, that the rousting with sult lleeomposes the base metals contained and leuves in the powder a combination of the various ncids evolved in the shape of n snlt or salts which, on being put into u pan and properly moistened with wuter for the purpose of amalgamation at once attack the iron of whieh the pan is composed. Iron pans used in mills where roasted ores are treated seldom last more thon from four to six nionths, whea their bottoms are found to be eaten through. ‘lhe enameled pnns will lust ut leust a yenr and u half—perhaps two yenrs. Tho eaamel is of a brown color when burnt and adheres so firmly to the iron that it cannot be cut off with uo chisel. Another peculiar and excellent property of the enamel is, that after huving been put upon the iron, vo subsequent heatings of the wetal uffect it. lt shrinks and expands with the iron, and, though a pan bottom coated with the enamel were heated red hot and dropped inte cold water, the enamel wonlil vot be iu the leust degree cracked or allected. ‘he enaitel is of a red color before being fixed to the iron by heat, ud is spread on the puns or inullers with a trowel in the slipe of a thin mortar. ‘The furnace, whieh is peeuliarly constr-eted, isof a eireular form and sufficiently large to tale in the largest sized pan, or pan bottom. Five pan bottoms cun he at onee enameied. ‘I'he interior of the furnace is made ol boiler iron with a brick wall outside, leaving a space all round of some six inches, into which chareonl can be led through six iron doors constrneted for the purpose. Besides the heat thus obtained there is underneath the furnace a large fire-place for Luruing wood. After the mullers, pans or pan bottoms huve been properly coated with the enameling composition they are placed in the lurnuce which is covered hy two conical lids of toiler iron, the inner one of which is four inches smaller than the outer, and the fires are started. Alter a red heat hus been kept up for tweuty-four hours the operation is complete. Although the piece of iroa to be coated may stand on its edge, the enamel does not rua off when itis melted. ‘he pun bottoms which are now being prepared for ename.ing are for the Manhattan Mill, Reese River, where tle ores are all roasted after crushing, and where they find their pans quickly rendered worthless lrom the actioa of the acids in the ores. Mr. Golden was fora long tinle engaged in the Central Mill in this city, where the dry erushing and roasting processes were used and where he liad a good eliance to see the necessity for sofme improvement in pans and ampic opportunity for trying all sorts of experiments upon enainels by merely coating pieces of iron with various materials and subjecting them to the heat of thé reverberatory furnaces used for roasting ores. ‘I’ne enamel will be valuable for many uses besides the coating of pans; it can be used upon puinp tubes and all kinds of iron pipe to protect them from rust. Prospecrinc Minz.— The editor of the Mountain Messenger informs us tbat the citizens of Downieville contemplate erecting a small and convenient prospecting mill in that towa, for the purpose of affording the miners thereabonts a cheap method of testiag their ores. Associations for similar purposes might be formed in many of our mouutaia towns, greatly to the encouragement of the mining interests of such localities, and the Improvement of business geaerully. Tar Borax YieLrn.—'he Napa Reporter ebronicles the arrival at Napa of a large wagon, laden with 11,500 pounds of borax, from the Borax Lake, ia Lake county. The driver informs the editor that he makes semiweekly trlps. Thus it will be seen that about 25,000 pounds of this mineral are shipped to San Francisco weekly by the company. -The pores is shipped in boxes of ahout 200 pounds each. rying, tunneling or stone-cuttiiy, has been the stow und tedioua one of percussion, by repeated tdows with a steel instrament upon ono spot, witil little by litile the desired orifice was formed. Several years ago a distinguished civil engineer of Geneva, Switzerlund, M. Rodulph Lesclot, being desirous of obtaining some more rapid and efficient method of quarrying roek thun uny then iu use, instituted a series of experiments ia different modes of cutting. It was not difficult to produce by niaclinery any desived motion of the cutting instrument, but the great and for a time uppurently iasurmountuble difficulty which iatervened was that the hard surface of the rock so rapidly ubraded the edges of even the hurdest steel instruments that really little pructieal ndvantage was gained over the old plun. What was to be done? The answer was at hond. The diainond hud loag been employed in eutting and polishing other precious stones ; why not employ itin piercing the inipructieable rock? It wus done. .A nmnber of diamonds sct in ths face of a cylindrical eutter hesd, at ones aecoutplished all that conld be desired, cuttiag a clean, circular groove (wheace the term * annular”) into the rock, destroying but litule of the taaterial, und leaviag a core which could be easily removed. ‘The first application of M. Leschot’s plan on alarge scale was ut Pistoja, Italy, wliere it was employed in cutting a ruilway tuunel, and gave th: fullest satisfaction to the engineers employed on ths work. «\ small steain drill, employiag this principle, is aow in daily operatioa ut No. 144 Creene street, in this eity, whieh fully illustrates at ouee the maaneraud the excellence of its operation, With ths application of comparatively very slight power, a hule 13 incheg in diameter is pierced in hard grauite at tho rato ol 134 inches per minute, In North river bluestone, it easily peaetrates three inches per minute. Both the cutter aad spindle being hollow, enables a stream of evld water to be constantly passed through them, keeping the instrument eoul, and*effectually clearing the hole of ull debris. ‘This machinehas now been several months in operution, cutting various specimens of granite, gneiss, North river bluestone, snnd-stone, and marble, and thus far with little or no apparent wear of the diamonds. The invention has been patented in England, on the contiaent and in this country, aud the eompany owniag the patent for ths United States are aow employed in maaufacturing machines for power aud band work, adapted to all the various uses to which the principle can be applied. J*or all purposes of rock-blastiag, either on land or in submarine operations, it appears to be excellently adapted, as it should operate equally well in any depth of water, orin cutting, excavating or quarlying on land. In prospecting for coal, or other miuerals or metuls, it would probably prove a very efficieut aid, as the core wh.ch it cuts out would show the successive geological formatidns of each foot of its progress, and eaable the miner-to drive a shaft with complete assurance of success.—New York Tribune. A Pronvcrive Mive.—We lenrn from Mr. G. B. V. DeLamater that the Cosunmnss Copper Co., whose miue is situated about four miles east of Michigan Bar, have sbipped this season over one thousand tons of copper ore, of very good quality. Some shipineats ussaying over 30 per cent, The main shaft is now 380 feet deep and they have copper ore at that depth. With a larger force the ore could be got out and shipped mors rapidly. ‘Ihe mine is but Ove miles from ths Placervilleand Saerameuto railroad, and has a g:eat advantage iu shipment of ore, over any copper mive in the State. : Tvotumne Mounrain Minixc Conpany.— The aynual meeting of this company, for the choice of officers, was held on Monday last, at the office of Byrne & Freeloa, Court Block. We understood that the company have raised and reduced quite aa amount of very good rock aad that the mine is a very proinising one. We have beea promissd some furtber particulars with regard to it, which we shall probably be able to give in a week or two. ‘Ihe stockholders are anxious to see a full report of the condition and prospects of the mine. a

The Hiining and Scientific Press. 295 *Wechanicat. Manufacturing and Tempering Sword-Blades An Important Pan Improvement. Tho Diamond Drill---Its History and a Deieee ————— ae in Indta. a ss scription of the Machine, Sta a SS — The Virghda Eaterpeise gives the blowing — BEFEOTS OF HEATING, ROLLING, HAMhe swonls uanufietural in the Regrury of deseviption nt the progess for mune inal . Pethane the most important provement ; : seceit hen, FERRE ve wit rR . Pa . ern 8 hee zd of Inte yeurs in the MERING, AND ANNEALING METALS. . een an "ali ve in ; a : s raunating ra a hie i we shuald suppose, might . jarportunt uml constantly increasing basiness Ch rave Ione been celebrated tu ledia for their) be"of muct vatne mul importatce : of rutting anil iressing stone, is the adopti ‘laborate exp? ta anil enreful ob-eren: . ae 7 on : ; Ba we UY LGUs Mis horate =p eS e a a wontlerful strength und enduring edge. The! We yesterday visited the new enameling . of the principie employed ip what is kuown ug tiene have devet ped) many poesia aie a fullowing dexeription of their mode of nimufac . furnace which bag jnst been cunatrneted ond is . tie Mandar Dhonond Drill, as mannfactared porta facts with regard ta. the variutie rc en roniatied w tho Hriicle pulticl about going mito eperntiat on UH street aur tis . by tue Sounbn Drill Cuipanys of this city. dencity, cle, which different inetals undergo ee ‘ ae city. “tlie Carnes, whiel is ct peenliar eon . Yorimay years the method ahnost oniversnlty in different degrees. in tho cperatinns of heutsome years siee, by oT English ariny officer Patrnetion. is the iuvention of Mr. Jota Han} employed to promnce troles ar ents in masses ‘ 1 i. a tan Reaiehiee aud, witnedtl who lil long held a amilitury command in that alone, aud the eusimel aypliect to the invention; of rock or ore, either in mining, blasting, quaring, drawing, rolling, meri al ing. “At a temperature rather nbove a cherry-red, icon wiro will remain three months, surronnded with charcoul.without cementation taking place, while a white heat will, in five miuutes, render brittle a sqnare bar of malleablo irou, eighttenths of un tach in diumeter. Wires of eapper, and of alloys of copper and ziae, ure increased in diainoter, and diminished jn density, by annealing. ‘Tho operation of rolling enndeases metals more thau thet of Wire-druwiug. ‘The density of iron and copper will be greater if the aetnis are heuted befors being passed through the rollers. ‘The reverss is the ease with alloys of copper and zinc. The deusity of metals is greatest. when drawa into very fing wires. Hence, two smull wires arg stronger thsu one largs one of the same transverse ares with the united areas of ths small ones. This result grows out of the fact that the particles of the smaller wires nre enmpacted throughout their entire eross: section, while those of the latter are thus eonipucted for o certnin depth oaly. : Wires may be increased in length in two wsys—first, by diniunition in the cnse of its ross seelion ; and second, but only in a slight degree, by increusiag the distanees between ths component particles. When wire is lengthened by the latter process, it returas to its former leagth hy annealfng. Again, wires of certain different metals, after psssing throngh the same hole in the wiredrawing plate, have different diameters ; but all such subsequently aequire equal diameters during the process of aanealiag. ‘lhe diameter of a wire is said to increase very slowly by time, after passing through a wire-drawing plate. Wires which have been bent, aad subsequently straightened, have a tendency to re-acquire the same curvature by time. Wires exposed toa high heat lose part of their tenacity. ‘Tey require to be anneuled in Wire-drawing, not to render them more tenacious, but to allow the particles to resume the positions from which they may again be displaced. The loss of tenacity is common to copper, iron, platiuum, and the alloys of copper and zine. Hydrogen has an action on copper and silver, at hich temperatures, which permaneatly separates their particles. Oa alloys of copper aud zinc, and even of silver and copper, it has no such actioa, Brass wire approaches to iron in strength, while copper wire is much inferior to it; hence, hrass is much used instead of iron where the latter would oxydize too rapidly. Troa wire is made of different qualities, to stand a strain from 75,000 up to 130,000 pounds to the square inch. The tenacity of brass iron varies from 78,000 to 87,000 pounds to the square iach ; while copper wire will part at from 38,000 to 44,000 pounds. These facts, with many others of a like character, have heea carefully arrived at by many and most elaborate experiments, aad a knowledge of them is valuable to every mechanic. —5 Oenrno’s Rervector.—This is the name of a new iavention just patented by John Oeding of this city, and designed as aa improvement oa the ordinsry kerosene lamp. It coasists of a simple lookiag-glass reflector, of any size desired, which is attuched to the lamp by a ring, aad placed at such an aagle as to reflect the light upon the proper place, at ths same time it sbades tbe eye from tbe blaze of the lamp. For writing, sewing, or other work requiring strong light, tbe reflector will be found very heneficial, while it can he afforded so cheap as . to be witbin the reach of all. . manufacturer in Horsforth, England, provinev, aud who had an opportunity of learning the prucess of matulacture und tempering employed in producing these wonderful blades : An inch bir of fius English or Swedish stecl is first foreed out into plates seven inclies long by one iuch broad, and one-sixth of nn inel thick. Similac bars of very fing sult iron wre then prepared in ths same manner. ‘These pieees of [urged steel snd irgn sre smeured over with # paste of horax, dissolved in water, and latd up in piles of between nine of steel Lo three of iron, ulternately; each pile is then wrapped arouud with thickly plastered ind, nade of a loamy earth; then heated, welded, and drawn out to aharol one ineh and oneeighth broad, and one-third of an inch thiek. Vhis is bent over upon itself three or lour times, and ngain welded and drawn ont to lulf nn iaeh in thickness, und duriag the heat borax is lrequently diopped on the wnetal while in the fire. ‘lwo or three burs of this metal thus prepared are next welded inty one, and when about twelve or fourteen inelies long, is bent into the form of a staple; in the middle of this piece x fine grained file is now inserted, of the same width aud nearly as thick as the bent bar; all is now welded toyether, nnd the blade then tormed. In tempering, an earthen pot, twelve inehes wide und six deep, is notehed on the edge, tle notehes being opposite to each other. The noteliing is.dune with a file,and about a quarter vt an inch deep. The pot is now filled nearly up to the notehes with water, and oil is then poured upon the surface. ‘Ihe sword-blide being heated eqnally to a light red leat, is removed from the fire, and the point entered iato the notch on oae edge is passed scross the surface of the oil and water to the opposite uoteh, keeping the edve from a quarter to half aainch iuthe oil; the blade is thus drawn backward and forsard rather slowly till the hissing ceases, and the rest of the blade above the fluid has beeyume black; ajng of water, without oil,is then poured alung the blade, lvom heel to point. In order to take out the warp produced by tempering, tlle blade, when aearly cold, is passed over the fire three or four times, then placed again upon the aavil, and set struight, bv strik ng it reeularly, but moderately, with the hammer. By this means a Damasens:eurved blade nay be brought uearly straight. Blades nade in this way are proved, previously to grinding, by striking them upon stones, ranirods, and gun-barrels. ‘Vhley may éven be struck violently upon wheel-tires, or heavy pieces of irun, without injury to the haninieied edge. Doty Arrreciaten.—We have several times had occasion to speak of the superiority of Hendy’s gang cirenlar saw-mills over the or. dinary saw-mill, both in the amount of work which it will turn off, and the manuer in which it turns its work out. T’be only mitl of this description yet in operatiou on this coast, is on Little River, Mendocino county. This mill recently turned out 32,500 feet of lumber in twelve hours. The eagine that ruus this mill is 14-inch bore and 18-inch stroke. The agent here says that the mill is not able to supply the demand, and oae of the mills is now being fitted up at Trinidad, Humboldt coanty, and will soon be sending its lumber into market. One million of feet are now oa hand ahead of the supply. This demand arises mainly from the superiority of the quality of the lumber which it produces. Ong of the most curious articles of an exhibition nos beiag held ia England, says the Chicago Journal, is a steam-engins and boiler, in miniature, and deseribed as the ‘ smallest steam-engine ia the world.” It stunds scarcely two inches in hight, and is covered with a glass shade. The fly-wheel is made of gold, with steel arms, and makes seven tbousand revolutioas per minute. The engiae and boiler are fasteaed together with thirty-eight miaiatore screws and bolts,the whole weighing fourteen grains, or under one-quarter of an ounce. ‘he manufacturer says that the ovaporation of one drop of water will drive the eagiae eight minutes. ‘bis dwarf piece of

mechaaism ‘was designed and--‘made by a clack ‘ob Mir. Charles It, Golden. Buth thy furnnee aud the enamel are patented. ‘fhe material used forms on niuliers, pau bottums aud the sites of puns a cvatiine similar to the enamel on niamy iron kettles used for culinary purposes, thuigh unlike this the eontposition of the euainel we spruk of is such that it with-. stands the action of ull kinds of ecids. ‘The . enmnelis intended to be use in coating the) interior of puns usedin mills where the ores ure erushed dry and rousted. Jt uppears that where ores are thus treated, that the rousting with sult lleeomposes the base metals contained and leuves in the powder a combination of the various ncids evolved in the shape of n snlt or salts which, on being put into u pan and properly moistened with wuter for the purpose of amalgamation at once attack the iron of whieh the pan is composed. Iron pans used in mills where roasted ores are treated seldom last more thon from four to six nionths, whea their bottoms are found to be eaten through. ‘lhe enameled pnns will lust ut leust a yenr and u half—perhaps two yenrs. Tho eaamel is of a brown color when burnt and adheres so firmly to the iron that it cannot be cut off with uo chisel. Another peculiar and excellent property of the enamel is, that after huving been put upon the iron, vo subsequent heatings of the wetal uffect it. lt shrinks and expands with the iron, and, though a pan bottom coated with the enamel were heated red hot and dropped inte cold water, the enamel wonlil vot be iu the leust degree cracked or allected. ‘he enaitel is of a red color before being fixed to the iron by heat, ud is spread on the puns or inullers with a trowel in the slipe of a thin mortar. ‘The furnace, whieh is peeuliarly constr-eted, isof a eireular form and sufficiently large to tale in the largest sized pan, or pan bottom. Five pan bottoms cun he at onee enameied. ‘I'he interior of the furnace is made ol boiler iron with a brick wall outside, leaving a space all round of some six inches, into which chareonl can be led through six iron doors constrneted for the purpose. Besides the heat thus obtained there is underneath the furnace a large fire-place for Luruing wood. After the mullers, pans or pan bottoms huve been properly coated with the enameling composition they are placed in the lurnuce which is covered hy two conical lids of toiler iron, the inner one of which is four inches smaller than the outer, and the fires are started. Alter a red heat hus been kept up for tweuty-four hours the operation is complete. Although the piece of iroa to be coated may stand on its edge, the enamel does not rua off when itis melted. ‘he pun bottoms which are now being prepared for ename.ing are for the Manhattan Mill, Reese River, where tle ores are all roasted after crushing, and where they find their pans quickly rendered worthless lrom the actioa of the acids in the ores. Mr. Golden was fora long tinle engaged in the Central Mill in this city, where the dry erushing and roasting processes were used and where he liad a good eliance to see the necessity for sofme improvement in pans and ampic opportunity for trying all sorts of experiments upon enainels by merely coating pieces of iron with various materials and subjecting them to the heat of thé reverberatory furnaces used for roasting ores. ‘I’ne enamel will be valuable for many uses besides the coating of pans; it can be used upon puinp tubes and all kinds of iron pipe to protect them from rust. Prospecrinc Minz.— The editor of the Mountain Messenger informs us tbat the citizens of Downieville contemplate erecting a small and convenient prospecting mill in that towa, for the purpose of affording the miners thereabonts a cheap method of testiag their ores. Associations for similar purposes might be formed in many of our mouutaia towns, greatly to the encouragement of the mining interests of such localities, and the Improvement of business geaerully. Tar Borax YieLrn.—'he Napa Reporter ebronicles the arrival at Napa of a large wagon, laden with 11,500 pounds of borax, from the Borax Lake, ia Lake county. The driver informs the editor that he makes semiweekly trlps. Thus it will be seen that about 25,000 pounds of this mineral are shipped to San Francisco weekly by the company. -The pores is shipped in boxes of ahout 200 pounds each. rying, tunneling or stone-cuttiiy, has been the stow und tedioua one of percussion, by repeated tdows with a steel instrament upon ono spot, witil little by litile the desired orifice was formed. Several years ago a distinguished civil engineer of Geneva, Switzerlund, M. Rodulph Lesclot, being desirous of obtaining some more rapid and efficient method of quarrying roek thun uny then iu use, instituted a series of experiments ia different modes of cutting. It was not difficult to produce by niaclinery any desived motion of the cutting instrument, but the great and for a time uppurently iasurmountuble difficulty which iatervened was that the hard surface of the rock so rapidly ubraded the edges of even the hurdest steel instruments that really little pructieal ndvantage was gained over the old plun. What was to be done? The answer was at hond. The diainond hud loag been employed in eutting and polishing other precious stones ; why not employ itin piercing the inipructieable rock? It wus done. .A nmnber of diamonds sct in ths face of a cylindrical eutter hesd, at ones aecoutplished all that conld be desired, cuttiag a clean, circular groove (wheace the term * annular”) into the rock, destroying but litule of the taaterial, und leaviag a core which could be easily removed. ‘The first application of M. Leschot’s plan on alarge scale was ut Pistoja, Italy, wliere it was employed in cutting a ruilway tuunel, and gave th: fullest satisfaction to the engineers employed on ths work. «\ small steain drill, employiag this principle, is aow in daily operatioa ut No. 144 Creene street, in this eity, whieh fully illustrates at ouee the maaneraud the excellence of its operation, With ths application of comparatively very slight power, a hule 13 incheg in diameter is pierced in hard grauite at tho rato ol 134 inches per minute, In North river bluestone, it easily peaetrates three inches per minute. Both the cutter aad spindle being hollow, enables a stream of evld water to be constantly passed through them, keeping the instrument eoul, and*effectually clearing the hole of ull debris. ‘This machinehas now been several months in operution, cutting various specimens of granite, gneiss, North river bluestone, snnd-stone, and marble, and thus far with little or no apparent wear of the diamonds. The invention has been patented in England, on the contiaent and in this country, aud the eompany owniag the patent for ths United States are aow employed in maaufacturing machines for power aud band work, adapted to all the various uses to which the principle can be applied. J*or all purposes of rock-blastiag, either on land or in submarine operations, it appears to be excellently adapted, as it should operate equally well in any depth of water, orin cutting, excavating or quarlying on land. In prospecting for coal, or other miuerals or metuls, it would probably prove a very efficieut aid, as the core wh.ch it cuts out would show the successive geological formatidns of each foot of its progress, and eaable the miner-to drive a shaft with complete assurance of success.—New York Tribune. A Pronvcrive Mive.—We lenrn from Mr. G. B. V. DeLamater that the Cosunmnss Copper Co., whose miue is situated about four miles east of Michigan Bar, have sbipped this season over one thousand tons of copper ore, of very good quality. Some shipineats ussaying over 30 per cent, The main shaft is now 380 feet deep and they have copper ore at that depth. With a larger force the ore could be got out and shipped mors rapidly. ‘Ihe mine is but Ove miles from ths Placervilleand Saerameuto railroad, and has a g:eat advantage iu shipment of ore, over any copper mive in the State. : Tvotumne Mounrain Minixc Conpany.— The aynual meeting of this company, for the choice of officers, was held on Monday last, at the office of Byrne & Freeloa, Court Block. We understood that the company have raised and reduced quite aa amount of very good rock aad that the mine is a very proinising one. We have beea promissd some furtber particulars with regard to it, which we shall probably be able to give in a week or two. ‘Ihe stockholders are anxious to see a full report of the condition and prospects of the mine. a