spiral (2)

. [Fr., from Lat. spiral is, from spira a coil, a twist, a wreath; Sp. espiral; Ital. spirale.] [SPIRE (2), 8.] A. As adjective : 1. Winding about a fixed point or center, and continually receding from it, like a watch-spring. "Some watches have strings and physies, and others none; some have the balance loose, and others regulated by a spiral spring, and others by hogs' bristles." -Locke: Human Understand ., bk. iii., ch. vi. 2. Winding about a cylinder or other round body, and at the same time rising or advancing forward. "From this a tube, or round body, was formed, by which the water, or air, or both, was carried in a spiral stream up to the clouds."- Cook : Second Voyage, bk. i., ch. vi. B. As substantive: 1. Geom.: A curve which may be generated by a boil, boy; pout, jowl; cat, çcil, chorus, I. Literally : 1. Full of or furnished with spines; thorny. *2. Like a spine; hence, slender. "Cold spinie gra hopper." Chapman. Homer's Iliad, iii. chin, bench; go, gem; thin, this; is the radius vector of that point. The law according to which the generatrix moves along the revolving line is the law of the spiral, and determines the nature of the curve. Any position of the revolving line, a umed at pleasure, is called the initial line. Spirals are known by the names of their inventors, or by terms derived from the properties by which they are characterized; as, the spiral of Arch i me des, hyperbolic spirals , logarithmic spirals , parabolic spirals , . 2. A helix or curve which winds round a cylinder like a screw. spiral-bit, s. A wood-boring tool, made of a twisted bar of metal, with a hollow axis. spiral-gearing, 8. [SPIRAL-WHEELS.] spiral pipe-oven, s. Metall .: An arrangement for heating air for the blast furnace, consisting of a long spiral of cast iron pipes, connected with each other by cemented socket joints, through which the air to be heated circulates.