Roget, Peter Mark

(born Jan. 18, 1779, London, Eng.—died Sept. 12, 1869, West Malvern, Worcestershire) English physician and philologist. In 1814 he invented a slide rule for calculating the roots and powers of numbers. He was instrumental in founding the University of London (1828). He is best known for his Thesaurus of English Words and Phrases (1852), a comprehensive classification of synonyms or verbal equivalents which he assembled during his retirement. He was a fellow (from 1815) and secretary (from 1827) of the Royal Society.

Source: Encyclopedia Britannica