Mexico is extraordinarily flat, and laid out as regularly at right angles as our own symmetrical towns. At the ends of all the streets the view is closed by mountains. Its flatness, together with its position in reference to the adjoining lakes, are circumstances which have occasioned great solicitude in the past, and still call for almost as much, on a different ground. Formerly it was danger of inundation; now it is defective drainage. Bad odors offend the nostrils, and stagnant gutters and heaps of garbage the sight, of the wayfarer about the interesting streets.
COMPARATIVE LEVELS OF LAKES.
The drainage problem, divested of the mystery with which it has been surrounded in learned treatises, is simply this. When the vast slope from the sea has been
surmounted, and the Valley of
Mexico—as high as the Swiss pass of St. Gothard—is reached, it is found to be
a shallow depression, containing six lakes. These are of many different
levels—Texcoco the largest and lowest.
On the edge of Texcoco, or in the midst of it, like another Venice, with canals for streets, was built ancient Mexico. This principal lake received the overflow of the others, and the city was subject to frequent inundations. It is even now, after a large shrinkage in the lakes, but
a little more than six feet, at its central portion, above Texcoco. The waters of the three upper lakes—San Cristoval, Xaltocan, and Zumnpango—were turned back as
