Chart of the head of navigation of the Potomac River shewing the route of the Alexandria Canal : made in pursuance of a resolution of the Alexa Canal Company Oct. 1838. Compiled from the surveys of Lt. Col. Kearney. Major Turnbull U.S.T.E., W.M.C. Fairfax, M.C. Ewing Civ. Engrs; W.J. Stone sc Wash. D.C.