Maps illustrating the Isthmus of Tehuantepec.

Part of the large body of interesting literature relating to schemes to build either a railway or a canal through the Isthmus of Tehuantepec. Barnard was a notable military engineer and was superintendent on the construction of the Delaware breakwater and improvements on the Hudson River and New Jersey harbours and works at the mouth of the Mississippi. His selection as chief engineer on the project proposed by the Tehuantepec Railroad Company of New Orleans came about as a result of his survey of the battlefields around Mexico City during the Mexican War.