cone of rays
Webster's Dictionary (GCIDE)
1.(Geom.) A solid of the form described by the revolution of a right-angled triangle about one of the sides adjacent to the right angle; -- called also a right cone. More generally, any solid having a vertical point and bounded by a surface which is described by a straight line always passing through that vertical point; a solid having a circle for its base and tapering to a point or vertex. [1913 Webster]
2.Anything shaped more or less like a mathematical cone; as, a volcanic cone, a collection of scori[ae] around the crater of a volcano, usually heaped up in a conical form. [1913 Webster]
Now had Night measured with her shadowy cone Half way up hill this vast sublunar vault.— Milton.[1913 Webster]
3.(Bot.) The fruit or strobile of the Conifer[ae], as of the pine, fir, cedar, and cypress. It is composed of woody scales, each one of which has one or two seeds at its base. [1913 Webster]
4.(Zool.) A shell of the genus Conus, having a conical form. [1913 Webster]
Cone of rays (Opt.), the pencil of rays of light which proceed from a radiant point to a given surface, as that of a lens, or conversely.
Cone pulley. See in the Vocabulary.
Oblique cone or Scalene cone, a cone of which the axis is inclined to the plane of its base.
Eight cone. See Cone, 1. [1913 Webster]