One of the most extraordinary works in the neighbourhood of the capital executed by the Spaniards, is the cut or canal above mentioned, which has been made to carry off the superabundant waters of lake Zumpango. It is carried through a mountain, and cost the labour of fifteen thousand Indians for nearly a year; its length is 21,653 feet, in breadth more than eleven feet, and in depth more than thirteen; it was completed in 1608. Beyond the mountain, this canal is carried on above 28,000 feet to the river Tula, which runs into the gulf of Mexico near Panuco. This canal was undertaken in consequence of the many and dreadful inundations the city had suffered, and it appears, that it may still be visited by this calamity, by the southern lakes being overflowed from the high mountains in their neighborhood. This wonderful gallery was however inefficient; for want of proper arching the earth fell in and closed the passage, and Mexico was inundated for the space of five years. After much discussion and trials of various other means, the subterraneous cut was entirely uncovered, and formed into an open trench; in many parts, upwards of 160 feet deep, and 300 in breadth at top, the old canal serving as the course for the water, and it yet does not answer the purpose, the slope of the banks not being sufficient, and the soil so friable that it is constantly falling. This work was put a stop to in 1789; and cost above one million forty thousand pounds sterling, and is 67,535 feet in length. In digging, fossil bones of the elephant species were discovered. Many unfortunate Indians perished in this undertaking, which displays an astonishing effect of human industry, but very little science. Canals have since been executed at enormous expence, to conduct the water from the lake Zumpango and St. Christoval to the cut; these, with the repairs, and the great cut itself, cost up to the year 1804, as computed by M. De Humboldt, the sum of 1,291,770_l._ It appears, that a new canal is about to be commenced from Lake Tezcuco to the cut just described, which is also to be in part deepened, the waters of Tezcuco being lower than those of Zumpango.