TAGLIA. In mechanics, the name given to a particular combination of pul leys. The taglia consists of a system of fixed pulleys collected in one common block, and also of a system of movable pulleys in a separate block, to which the weight is attached, with one string going round all the pulleys, and having one of its ends fixed to a point in the system, and the other end going from one of the fixed pulleys drawn by the power. Some times several taglias are combined, so that one acts upon the other ; the system is then a compound taglia. (See PULLEY.) TALC. A mineral which is divided into two species, . the common and the indurated. The first occurs mas sive, disseminated in plates, imitative, or crystallized in small six-sided tables. It is splendent, pearly, or semi-metallic, translucent, flexible, but not elastic. It yields to the nail ; spec. gray. 2.77. Be fore the blowpipe, it first whitens and then fuses into an enamel globule. It
consists of—silica, 62; magnesia, 27; alumina, 1.5; oxide of iron, 8.5; water, 6. Klaproth found 21 per cent. of pot ash in it. It is found in beds of clay slate and mica-slate, in New England. It is an ingredient in rouge for the toilette, communicating softness to the skin. It gives the flesh polish to soft alabaster figures, and is also used in porcelain paste.
The second species, or talc-slate, has a greenish-gray color ; is massive, with tabular fragments, translucent on the edges, soft with a white streak ; easily cut or broken, but is not flexible ; and has a greasy feel. It occurs in the same localities as the preceding. It is employ ed in the porcelain and crayon manufac tures; as also as a crayon itself, by car penters, tailors, and glaziers.