TEHUANTEPEC, an isth mus of Mexico lying between the gulfs of Campeche (Campeachy) and Tehuantepec, with the Mex ican States of Tabasco and Chi apas on the east and Vera Cruz and Oaxaca on the west. It in cludes that part of Mexico lying between the 94th and 96th meridians of longitude W., or the south-eastern parts of Vera Cruz and Oaxaca, with perhaps small districts of Chiapas and Tabasco. It is 125m. across at its narrowest part from gulf to gulf, or to the head of Laguna Superior on the Pacific coast. The Sierra Madre breaks down at this point into a broad, plateau-like ridge, whose elevation, at the highest point reached by the Tehuantepec railway (Chivela pass) is 735 feet. The northern side of the isthmus is swampy and densely covered with jungle. The whole region is hot and malarial, except the open elevations where the winds from the Pacific render it comparatively cool and healthful. The annual rainfall on the At lantic or northern slope is 48 in. (10 year average) and the maxi mum temperature about 95° in the shade. The Pacific slope has a light rainfall and dryer climate.
Since the days of Cortes, the Tehuantepec isthmus has been considered a favourable route, first for an interoceanic canal, and then for an interoceanic railway. Its proximity to the axis of in
ternational trade gives it some advantage over the Panama route, which is counterbalanced by the narrower width of Panama. When the great cost of a canal across the isthmus compelled en gineers and capitalists to give it up as impracticable numerous projects for the construction of a railway were undertaken and abandoned. At last, in 1899 work was undertaken for the Mexican Government and was finished to a point where its formal opening for traffic was possible in 1907.
The railway is 192m. long, with a branch of 18m. between Juile and San Juan Evangelista. The minimum depth at low water in both ports is 33ft., and an extensive system of quays and railway tracks at both terminals affords ample facilities for the expeditious handling of heavy cargoes. At Santa Lucretia, 109m. from Salina Cruz, connection is made with the Vera Cruz and Pacific railway (a government line), 213m. to Cordova and 31 m. to Mexico city.