Bache, A. D. (Alexander Dallas), 1806-1867, Pritchett, Henry S. (Henry Smith), 1857-1939, Tittmann, O. H. (Otto Hilgard), 1850-1938, and Harrison, A. M. (Alexander Medina), 1829-1881. U.S. Coast and Geodetic Survey ; H.S. Pritchett, superintendent ; verified: O.H. Tittman, assistant in charge of the Office ; Gershom Bradford ... ... The Survey.