houses at these three places, and the Mexican National Railway crosses the Mexican Central at Huehuetoca.
The elevation of this point is 7,533 feet above the sea-level, according to Humboldt, or about 140 feet higher than the measurement of the railway-engineers. In general, it may be said that the distinguished German traveler and scientist, in taking altitudes with his barometer throughout the country, computed the elevations of the various points at somewhat higher figures than those of the engineers of the several railroads. Wheat and maize are cultivated in the vicinity of Huehuetoca.
This village is famous in Mexican History as being the scene of one of the greatest hydraulic operations ever undertaken by man. Frequent inundations of the City of Mexico, in the latter part of the sixteenth century, convinced the Spaniards that the system of dikes was insufficient to protect the capital. It was decided that the artificial draining of the Lakes of Tezcuco, Zumpango, and San Cristobal, would be necessary.
Two intelligent men, Obregon and Arciniega, proposed to the Government that a gallery should be made through the hills of Nochistongo, to the north-northwest of Huehuetoca. This spot was perhaps the lowest in the mountains bounding the valley of Mexico on the north. In 1607 the Marquis de Salinas, then viceroy, employed Enrico Martinez to begin the stupendous work of building a tunnel through the hills to drain the Mexican lakes. It received the name of the Desague (canal) de Huehuetoca. Work on the famous gallery of Nochistongo was commenced on November 28, 1607. The viceroy, in the presence of the audiencia, applied the first pickaxe, and 15,000 Indians were given employment. After eleven months of continued labor, during which many hundreds of Indians perished from severe treatment, the tunnel (el socabon) was completed. Its length was more than four miles, its width eleven and a half feet, and its height fourteen feet.
The water flowed through the canal for the first time on September 17, 1608. In the following December the viceroy and Archbishop of Mexico were invited by Martinez to witness it running, from the Lake of Zumpango and the Rio de Cuaulitlan, through the tunnel. The Viceroy Salinas is said to have ridden upward of a mile into this underground passage.
Scarcely had the water begun to flow from the valley of Mexico toward the Atlantic Ocean, when the canal was found to be too small. The loose earth surrounding the tunnel began to crumble, and it became necessary to support the roof, which was composed of alternate strata of marl and stiff
