lco and Xochimilco,
however, are very different in their regimen and aspect. They are of
fresh water, and stand at an elevation some 10 feet higher than
Texcoco, into which they discharge. Fertile meadows surround these, and
Xochimilco is now, as it was at the time of the Conquest, a "Field of
Flowers," which is the meaning of its native nomenclature, not unworthy
of the designation of an "earthly paradise," which the modern Mexicans
bestow upon it.

[Illustration: THE VALLEY OF MEXICO: THE GREAT DRAINAGE CANAL.]

The position of the City of Mexico near Lake Texcoco, which receives
the waters of all the other lakes of the system, has ever rendered it
liable to inundation, and to a saturated and unhealthy subsoil,
conditions which, were it not for the healthy atmosphere of the bracing
uplands whereon the valley is situated, would undoubtedly make for a
high death-rate. The drainage and control of the waters of the valley
have formed matters of thought for Mexico's successive Governments for
more than four centuries. Work to this end was begun under Montezuma in
1449, nearly three-quarters of a century before the Conquest. During
the colonial _regime_ further works were undertaken, in 1553, to
replace those destroyed by Cortes, followed by other works in 1604 and
1708. But only after the Republican _regime_ was established was the
work carried to completion, upon a plan brought forward by a Mexican
engineer. These works, which were mainly carried out during the closing
years of last century by English firms of engineers and
contractors,[28] consist of a canal and tunnel. The canal is thirty
miles long, flowing from the city and bearing its sewage and
storm-waters, and taking the overflow from Lake Texcoco: and
discharging thence into a tunnel, perforating the rim of the valley,
about six and a half miles long. This in turn empties into a discharge
conduit and a ravine, and the waters, after having served for purposes
of irrigation and for actuating a hydro-electric station, fall into an
affluent of the Panuco river and so into the Gulf of Mexico. This work,
which is the climax of the attempts of four hundred years or more,
reflects much credit upon its constructors and the Government of Diaz,
which financed it at a total cost of sixteen million Mexican dollars.

[Footnote 28: S. Pearson & Sons, Ltd., London, and Read, Campbell &
Co.]

An Aztec hydraulic work of the Valley of Mexico is the Viga Canal,
which leads from