MEXICO CITY, capital and metropolis of the Republic of Mexico, and chief town of the Federal District, near the southern margin of the great central plateau of Mexico, in lat. 19° 25' 45" N., long. 99° 7' W. It is about 200 m. in a direct line W. by N. of Veracruz, its nearest port on the Gulf of Mexico, with which it is connected by two railway lines, one of which is 264 m. long; and about 181 m. in a direct line N.N.E. of Acapulco, its nearest port on the Pacific, with which it is connected partly by rail and partly by a motor road. The city had a population of 1,029,068 at the census of 1930 (461,659 males and 567,409 females), including several suburbs annexed officially in 1931. The majority of the inhabitants is composed of Indians and mestizos, from whom come the factory workers, labourers, servants, porters and other wage-earners. The foreign population includes many capitalists and industrial managers, who are doing much to develop the country, the large American colony being concentrated in a fine modern residential district in the The city stands on a small plain occupying the south-western part of a large lacustrine depression known as the Valley of Mexico (El Valle de Mexico), about 3 m. from the western shore of Lake Texcoco, whose waters once covered a consider able part of the ground now occupied by the city. The valley, in cluding the drainage basin of Lake Zumpango, has an area of 2,219 sq.m. (1,627 sq.m. without that basin). The elevation of the city above sea-level is 7,415 ft., only a few feet above the level of Lake Texcoco. The general elevation of the valley is about 7,500 ft., that of Lake Zumpango being 7,493 ft., and of Lake Chalco 7,48o feet. The rim of the valley is formed by spurs of the cordillera on all sides—the Sierra de Guadalupe (65o to 750 ft. above the city) on the north, the Sierra Nevada, with its snow-clad peaks of Popocatepetl and Ixtaccihuatl farther away to the south-east, the Sierra de Ajusco, and the Montes de las Cruces bordering the depression on the south and west. Earthquake shocks are of frequent occurrence, but the city rarely suffers any material damage. The great earthquake shocks of July 3o and 31, 1909, however, caused considerable damage in the city, and a few lives were lost.
Lake Texcoco is a shallow body of brackish water, with area of about 1 1 sq.m., and is fed by a number of small streams from the neighbouring mountains, and by the overflow of the other lakes. Its shores are swampy and desolate and show considerable
belts of saline incrustations with the fall of its level. The Aztecs settled there because of the security afforded by its islands and shallow waters.
The Chalco and Xochimilco lakes, 8 or 9 m. to the southward, which are separated by a narrow ridge of land, are connected with the lower part of the city by an artificial canal called "La Viga," 16 m. long and 3o ft. wide, which serves as an outlet for the overflow of those lakes and as a waterway for the natives, who bring in flowers and vegetables for sale. Lake Xochimilco, celebrated for its chinampas or "floating gardens" (see MEXICO, FEDERAL DISTRICT OF), is supplied largely by fresh-water springs opening within the lake itself. Lake Chalco is greatly reduced in size by railway fillings and irrigation works.