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alloy alumina ammonia amount analyses antimony arsenic assay assayers black-copper blende bottom brass button calamine calcined carbonic acid cavities cent charcoal charge coal coarse-metal cobalt coke colour combustion consists containing copper-ores copper-smelting copper-works crucible crystalline crystals dioxide of copper disulphide of copper employed experiment exposed formed fracture fuel furnace fusion grains hydrochloric acid hydrogen inches ingot iron-pyrites kiln less lime lustre mass matter melted metallic copper mixture mould nickel nitric acid obtained occurs operation ore-furnace oven oxide oxide of iron oxide of zinc oxygen particles pieces pile powder present produced proportion protoxide of copper protoxide of iron pyrites red heat reduced refining regulus residue retorts reverberatory furnace roasted sesquioxide silica slag small quantity smelters smelting soda solution specific gravity specimen sulphate sulphide sulphide of zinc sulphuric acid surface Swansea tion tons tube weight wood yield zinc
Seite 360 - Under the microscope the filaments present numerous minute parallel and longitudinal lines or grooves, as though they consisted of bundles of extremely delicate fibres. . . . " The mode in which these fibres are produced is an interesting subject of inquiry. Each fibre seems to have been pushed, as it were, through a draw-plate, and at a temperature when the metal was soft, but certainly not exceeding that of well-melted copper, for otherwise the fibres immediately after their protrusion would have...
Seite 10 - Franz remarked that whatever the quality may be upon which calorific conduction depends, the close agreement of the figures renders it exceedingly probable that the same quality influences in a similar manner the transmission of electricity; for the divergence of the numbers expressing the conductivity for heat from those expressing the conductivity for electricity are not greater than the divergences of the latter alone, exhibited by the results of different observers.
Seite 46 - ... be obtained by alloying the three metals together in different proportions. When such a series of alloys has been once prepared, the heat of any furnace may be expressed by the alloy of least fusibility which it is capable of melting.
Seite 518 - The orichalcum of Cicero, which closely resembled gold, was really brass, this alloy of copper and zinc being the only metallic substance which it is possible to conceive the ancients could have so mistaken,
Seite 53 - Rumford estimated the calorific power of a body by the number of parts, by weight, of water, which one part, by weight, of the body would, on perfect combustion, raise one degree in temperature. Thus, one pound of charcoal, in combining with 2f Ibs.
Seite 360 - ... pressure, in a similar manner to maccaroni, can hardly be entertained. There seems to be a force in operation at the base of each filament, which causes the particles of silver at the moment of liberation successively to arrange themselves in one continuous fibre, or series of fibres ; or in other words, each filament grows, as it were, from a root imbedded in sulphide of silver.
Seite 309 - ... yet the prejudice against innovation was so strong, that in Admiral Keppel's fleet, 1778, there was only one coppered ship." Copper-smelting. A prodigious quantity of copper is obtained from Lake Superior. Mr. Petherick, the well-known mining engineer, informed Dr. Percy that at Minnesota, in 18,54, not fewer than forty men were engaged during twelve months in cutting up a single mass of native copper, weighing about 500 tons ! The native copper at Lake Superior in some places occurs curiously...
Seite 71 - Ibs. avoirdupois per г| acres. This contains 3968 Ibs. of carbon, and 57 Ibs. of hydrogen in excess of that required to form water with the oxygen of the wood. He has calculated that a bed of coal containing 85 per cent, of carbon, corresponding to the annual growth of these forests per...
Seite 619 - Best selected copper and foreign zinc are directed to be used. The metal is cast into ingots, and rolled while hot into sheets, which, when finished, are pickled in dilute sulphuric acid to remove the adhering scale, and afterwards swilled in water.