1 map ; 58 x 91 cm Relief shown by hachures. "Astronomically determined and surveyed in 1855. under the direction of William H. Emory, U.S. Commissioner." "Latitude and Longitude by W. H. Emory, assisted by J. H. Clark." "Trangulation and Topography by M. von Hippel, assisted by J. E. Weyss." "Engr. by Selmar Siebert." Prime meridian : Greenwich. Includes "View along the boundary line-looking E. from monument No. 3" and "View of the initial point of the boundary line on the Rio Bravo Del Norte-looking W" Ino. Weyess del., W. H. Douglas. "No. 29."