A Treatise on the Progressive Improvement & Present State of the Manufactures in Metal: Tin, lead, copper & other metalsLongman, Brown, Green & Longmans, 1853 |
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A Treatise on the Progressive Improvement and Present State of the ..., Том 3 John Holland Просмотр фрагмента - 1831 |
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acid afterwards alloy ancient appear applied Argand burner bell Birmingham bottom brass Britannia metal bronze burnishing buttons calamine calcined called cast celts centre circular clock coin colour consists containing copper Cornwall crucibles cupel Derbyshire described diameter edges electrotype employed feet furnace gold groove hammer heat hole inches ingenious instrument iron ladle lamp latter lead lever manner manufacture means melted method miners mines motion mould obtained operation ornaments ounces oxide pallet passed patent pendulum perfect pewter piece pinion pipe placed planishing plate polished portion precious metals present produced proportion purpose quantity rack red heat reverberatory furnace rolling round sal ammoniac sand screw sheet side silver sliding smelting solder sort spindle stamped steel striking surface swages telescope thickness tion tons tube turned vessels wares weight wheel wire workman zinc
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Стр. 151 - ... a land of brooks of water, of fountains and depths that spring out of valleys and hills; a land of wheat, and barley, and vines, and...
Стр. 218 - I endeavoured in vain to assay a small part ; the natives regard it with superstitious veneration, and they would not allow even a grain to be filed off...
Стр. 363 - The extent of the diluvial deposits is commensurate, or nearly so, with that of the gold-bearing region, in that part of the country which I have examined. They are found in a belt of land from thirty to sixty miles broad, and running parallel with the axis of the range ; and, from facts that I have ascertained from others, I have no doubt but that they exist throughout all the goldbearing region, both north and south.
Стр. 351 - And a river went out of Eden to water the garden; and from thence it was parted, and became into four heads. The name of the first is Pison: that is it which compasseth the whole land of Havilah, where there is gold; and the gold of that land is good: there is bdellium and the onyx stone.
Стр. 170 - ... to bring it to the proper pitch. The copper in this state is what is termed dry. It is brittle, is of a deep red colour, inclining to purple, an open grain, and a crystalline structure. In the process of toughening, the surface of the metal in the furnace, is first well covered with charcoal. A pole, commonly of birch, is then held in the liquid metal, which causes considerable ebullition, owing to the evolution of gaseous matter; and this operation of poling is continued...
Стр. 303 - Under the magnificent patronage of George III., he began, in 1785, to construct a telescope forty feet long, and on the 27th of August, 1789, the day on which it was completed, he discovered with it the sixth satellite of Saturn. The great speculum had a diameter of 49£ inches, but its concave surface was only 48 inches.
Стр. 39 - The asterisks show the places where the workmen stand, and also mark those pots which have heated flues under them. No. 4 has no fire under it. The parting in the wash-pot No. 2 is a late improvement. The design of it is to keep the dross of the tin from lodging in that part of the vessel where the last dip is given to the plates. By using the common tin in the first process of tinning, much oxide, or dross, adheres to the surface of the plates, and this runs off in the wash-pot, and comes to the...
Стр. 217 - Moscow, like the fullest tones of a vast organ, or the rolling of distant thunder. This bell is suspended in a tower called the belfry of St. Ivan, beneath others, which, though of less size, are enormous. It is...
Стр. 41 - ... attention, because, as the plate is immersed in the grease while the tin is in a melting, or at least in a soft, state upon it, a part must run off, and the remainder become less and less while the plate continues in it ; therefore, if these plates should eve'r be left in the melted tallow longer than is absolutely necessary, they will doubtless require to be dipped a third time in the tin. On the other hand, if 'the plates were to be finished without passing through the grease, they would retain...
Стр. 16 - ... a work of mere bodily labour. The use of machinery then became practicable, and a frame of boards being applied to the mouth of the shaft, it was cemented to the rock by pitch and oakum, made water-tight in the same way, and carried up to a sufficient height above the highest spring tide.