Annual report of the chief engineer and general superintendent of the Washington Aqueduct : Department of the Interior, Office of the Washington Aqueduct, Washington, D.C., October 1, 1864 Seymour, Silas, 1817-1890. Water Supply Sanitary Engineering [Washington, D.C.] : [U.S. G.P.O.], [1864] Flad, Henry, former owner. Text 17 pages nlm:nlmuid-101670777-bk 101670777 http://resource.nlm.nih.gov/101670777 OCLC: 930014480 English District of Columbia The National Library of Medicine believes this item to be in the public domain : https://creativecommons.org/publicdomain/mark/1.0/