to the
Pacific Ocean near San Blas.

[Illustration: FALLS OF JUANACATLAN: THE NIAGARA OF MEXICO.]

Southwardly from the above, beyond the intervening Cordillera, is the
River Balsas, or Mescala, 430 miles in length. This important stream
has its rise in the watershed of the central plateau, or rather the
extensive slopes of the Valley of Mexico, and running with a general
westerly direction between the Sierras, empties into the Pacific at
Zacatula. It is navigable for a short distance. The Yaqui, discharging
into Pacific waters, is 390 miles long, flowing through the Sierras of
Sonora to the Gulf of California. On the littoral of the Mexican Gulf
is the Panuco, which rises to the north of the Valley of Mexico,
flowing thence in a great curve; and being joined by various affluents
from the eastern watershed of the Sierra Madres, it discharges at the
port of Tampico. The Papaloapam, also draining part of the State of
Vera Cruz, empties into the Gulf near the port of the same name. From
the region of the peninsula of Yucatan flow two main streams--the
Usamacinta and the Grijalva--which are partly navigable. All these
rivers are further described in the chapter treating of the various
States to which they correspond. Another characteristic stream of
Mexico is the River Nazas, whose waters, nearly all absorbed by the
irrigation canals of the Laguna region, where the famous cotton
plantations are, fall in times of flood into the Lagoon of Parras,
where they evaporate, the system forming a hydrographic entity, without
outlet either to the Pacific or Atlantic watershed. Thus it is seen
that most Mexican rivers simply rise in and descend on one or the other
slopes of the country; and as the fall is rapid their courses are
interrupted by numerous cascades. Except in few cases, these rivers are
of no service for navigation, but the elements of water-power and
irrigation facilities which they possess are more than compensating
circumstances. In addition, their scenic value is very marked in many
cases.

Lakes of Andine character, and others, exist throughout Mexico, the
remnants of much larger lake systems, which occupied the filled-up
"troughs" of the mountains, before described. Some of these sheets of
water are exceedingly beautiful in their disposition and environment.
Foremost among them is Chapala, in the State of Jalisco, near the
handsome city of Guadalajara; and equally picturesque those smaller
sheets of water in Mich