Turning and Mechanical Manipulation: Intended as a Work of General Reference and Practical Instruction, on the Lathe, and the Various Mechanical Pursuits Followed by Amateurs, Band 1


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Seite 298 - Indeed where the articles to be covered are small, or their parts minute, such as wire, nails or small chain, it is necessary before immersing them to permit the triple alloy to dissolve or combine with some wrought-iron, in order that its affinity for iron may be partially satisfied and thus diminished. At the proper fusing temperature of this alloy, which is about 680° Fahr., it will dissolve a plate of wrought-iron of an eighth of an inch thick in a few seconds.
Seite 134 - The Mammoth or Elephant's bones and tusks, are found throughout Russia, and more particularly in Eastern Siberia and the Arctic marshes. The tusks are found in great quantities, and are collected for the sake of profit, being sold to the turners in the place of the living ivory of Africa, and the warmer parts of Asia, to which it is not at all inferior.
Seite 281 - In its ordinary state at common temperatures, it is tough, and with difficulty broken by blows of the hammer. It becomes very brittle when its temperature approaches that of fusion, which is about 773°; but at a temperature a little above 212°, and between that and 300°, it becomes ductile and malleable, and may be rolled into thin leaves, and drawn into moderately fine wire, which however, possesses but little tenacity. When a mass of zinc, which has been fused, is slowly cooled, its fracture...
Seite 142 - The substance of the ivory is not in all cases thus injured by the balls, and Mr. Combe (Philos. Trans. 1801, p. 165,) explains in a very satisfactory manner, how a bullet may enter the tusk of an elephant and become embedded in the ivory without any opening for its admission being perceptible. This he elucidates on the supposition of the ball entering at the root, descending into the hollow, and being covered up by the growth of the layers, which are...
Seite 101 - The bark of the sandal-wood gives a most beautiful red or light claret-coloured dye, but it fades almost immediately when used as a simple infusion ; in the hands of the experienced dyer it might, it is supposed, be very useful. There are woods described in the French works as red sandal-woods, and one specimen is so marked in Baker's collection ; probably they are varieties of red saunders or sapan woods.
Seite 140 - After the most careful scrutiny on the outside of the tooth, however, the first cut is alviayt one of a little anxious expectation, as the prognostics are far from certain ; and, before proceeding to describe the preparation of ivory, I will say a few words of its internal appearance when exposed by the saw. " The African ivory, when in the most perfect condition, should appear, when recently cut, of a mellow, warm, transparent tint, almost as if soaked in oil, and with very little appearance of...
Seite 94 - Ceylon, for the construction of flat roofs ; the joists of which consist of two slabs, the third or fourth part of the tree, bolted together by their flat sides so as to constitute elliptical rafters. They are covered first with flat tiles, and then with a white concrete called Chunam, consisting of shell lime, yolks of eggs, and Jaggree, (sugar,) beaten together with water in which the husks of the cocoa-nuts have been steeped.
Seite 429 - ... positions ; this is done with soft iron binding-wire, which for delicate jewelry work is exceedingly fine, and for stronger works is the twentieth or thirtieth of an inch in diameter ; it is passed around the work in loops, the ends of which are twisted together with the pliers. In soft soldering, the binding wire is scarcely ever used, as from the moderate and local application of the heat, the hands may in general be freely used in retaining most thin works in position during the process. Thick...
Seite 281 - temper," are added to every block of tin weighing from 360 to 390 pounds. Antimony is said to harden tin and to preserve a more silvery color, but is little used in pewter. Zinc is employed to cleanse the metal rather than as an ingredient ; some stir the fluid pewter with a thin strip, half zinc and half tin ; others allow a small lump of zinc to float on the surface of the fluid metal whilst they are casting, to lessen the oxidation.
Seite 103 - Tenasserim coasts. It grows quickly, straight, and lofty ; the wood is light and porous, and easily worked, but it is nevertheless strong and durable ; it is soon seasoned, and being oily, does not injure iron, and shrinks but little in width. Its colour is light brown, and it is esteemed most valuable timber in India for ship-building, house-carpentry, &c.

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