A pointed rod or wand, employed by professors of geometry, astronomy, or mathematics
for describing diagrams in sand, etc. (Cic. Tusc. v.
; Verg. Ecl. iii. 40
). A ray of light, usually repre
Urania with Radius. (Pompeian painting.)
sented by artists as a sharp pointed spike; whence corona radiis
(Flor. iv. 2, 91
), a crown ornamented with metal
spikes to imitate the rays of the sun.
). The spoke of a wheel (
Georg. ii. 444
Met. ii. 318
); so termed because it radiates from the nave, like a ray
of light from a centre; hence rota radiata
(Varro, R. R.
iii. 5.15), a wheel with spokes as contradistinguished from the solid wheel (tympanum
), which had none.