HELIX, in Geometry, a spiral line. See SPIRAL. —The word is Greek, ἥλιξ, and literally signifies "a wreath or winding;" of ἵσσεσθαι, involve, "I environ."
In architecture, some authors make a difference be-
tween the helix and the spiral. A staircase, according to Daviler, is in a helix, or is helical, when the stairs or steps wind round a cylindrical newel; whereas the spiral winds round a cone, and is continually approaching nearer and nearer its axis.