lakes. Yet even in the time of Cortes, these lakes had no great depth of water, and still further back, in the time of the Indian Emperors, navigation had been so frequently interrupted in seasons of drought, that an aqueduct had been constructed in order to supply the canals with water.
After this the Spaniards, like all new settlers, hewed down the fine trees in this beautiful valley, both on plain and mountain, leaving the bare soil exposed to the vertical rays of the sun. Then their well-founded dread of inundation caused them to construct the famous Desagüe of Huehuetoca, the drain or subterranean conduit or channel in the mountain, for drawing off the waters of the lakes, thus leaving marshy lands or sterile plains covered with carbonate of soda, where formerly were silver lakes covered with canoes. This last was a necessary evil, since the Indian Emperors themselves were sensible of its necessity, and had formed great works for draining the lakes, some remains of which works still exist in the vicinity of the Penon. The great Desagüe was begun in 1607, when the Marquis of Salinas was Viceroy of Mexico; and the operations were commenced with great pomp, the Viceroy assisting in person, mass being said on a portable altar, and fifteen hundred workmen assembled, while the Marquis himself began the excavation by giving the first stroke with a spade. From 1607 to 1830, eight millions of dollars were expended, and yet this great work was not brought to a conclusion. However, the limits of the two lakes of Zumpango and San Cristobal, to the north of the valley, were thus greatly
