Radius
Radius
1. A straight pointed rod used by geometricians and astronomers for describing figures on their abacus, a table covered with sand. (Cic. Tusc. 5.23, 64, a pulvere et radio,
of Archimedes; cf. Cic. N. D. 2.1. 8, 48, eruditum illum pulverem,
of geometry; Pers. 1.131; Aristoph. Cl. 177.) In Verg. Ecl. 3.41, Aen. 6.850, it is probably the actual rod (as above) used for the actual drawing of terrestrial and celestial globes on the abacus, rather than, as Conington says, a mere phrase for scientific delineation.
[See also ABACUS III. a.]
2. Used in weaving. [TELA]
3. Of a wheel. [CURRUS]
From William Smith (ed.), Dictionary of Greek and Roman Antiquities. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.