Spiral

(spiral.) [ From Gr. spe ira, anything wound round another. ] (Geom.) A curve which winds round a centre, and in its progre continually increases its distance from that centre. The fuse or spring of a watch gives a good idea of this curve. There are various kinds of spirals, which have received their names from their inventors or their properties; thus, the S. of Arch i me des, the hyperbolic S., . (See HELIX.)(Arch.) A curve that ascends winding about a cone or spire, so that all points continually approach its axis. [s. 847]