No.I. General map of the American Isthmuses showing the various lines proposed for Interoceanic communication, compiled by Rear Admiral C.H. Davis, U.S.N. Superintendent U.S. Naval Observatory, Washington D.C. "To accompany Report ordered by resolution of the Senate of the United States of March 19th. 1866". Drawn by Louis Waldecker, Washington. Bowen & Co. Lith. Philada.