1911 Encyclopædia Britannica/Walker, Sears Cook

WALKER, SEARS COOK (1805–1853), American astronomer, was born at Wilmington, Massachusetts, on the 28th of March 1805. Graduating at Harvard in 1825, he was a teacher till 1835, was an actuary in 1835-1845, and then became assistant at the Washington observatory. In 1847 he took charge of the longitude department of the United States Coast Survey, where he was among the first to make use of the electric telegraph for the purpose of determining the difference of longitude between two stations, and he introduced the method of registering transit observations electrically by means of a chronograph. He also investigated the orbit of the newly discovered planet Neptune. He died near Cincinnati on the 30th of January 1853. His brother Timothy (1802-1856) was a leader of the Ohio bar.

See Memoirs of the Roy. Astr. Soc. vol. xxiii.