He achieved the rare distinction of obtaining an optime for both Greek and for physics.

in 1843, being seventh in the first class of the classical tripos and a senior optime.

He was educated at Glasgow University and at Trinity College, Cambridge (senior optime, and classical honours); was returned to parliament for Stirling as a Liberal in 1868 (after an unsuccessful attempt at a by-election); and became financial secretary at the war office (1871-1874; 1880-1882), secretary to the admiralty (1882-1884), and chief secretary for Ireland (1884-1885).

Relations came to his aid, and presently his anxieties were relieved by Francis Martin, bursar of Trinity, who gave him liberal help. Benson took his degree in 1852 as a senior optime, eighth classic and senior chancellor's medallist, and was elected fellow of Trinity in the following year.