Langley was an assistant observer at Harvard College Observatory from 1865-66 (under the directorship of Joseph Winlock). Together with Austin, Peirce, Searle and Winlock he observed nebulae with the 15" f/18 Merz-refractor installed in June 1847 (see picture). The results are published in Ann. Harv. Obs. 13, 62 (1882). Langley discovered 1 object: NGC 3355 (HN 215) on April 12, 1866, a galaxy in Hydra. HN stands for "Harvard Nebula", given in Pickering, E. C., Detection of Nebulae by Photography, Ann. Harv. Obs. 18, 113-117 (1890).

Obituary: MNRAS 67, 239 (1907); ApJ 23, 271 (1906); AN 171, 91 (1906)

Harvard Observatory with 15" Refractor