Alexander Ross Clarke (1828–1914)

Geodesist. Graduated from the Royal Military Academy, Woolwich, and was commissioned as a second lieutenant in the Royal Engineers, 1847. Posted to the Ordnance Survey in Southampton, 1850; chief mathematical and scientific adviser, and head of the trigonometrical and levelling departments, from 1856. In 1860, began a comparison of different national standards of length. Retired in 1881. FRS 1862.