MINES—RIVERS—LAKES. 349 
the other parts of America and the corresponding 
latitudes in Europe; but it is less perceptible on the 
western than on the eastern coasts. 
New Spain possesses a peculiar advantage in 
the circumstances under which the precious metals 
have been deposited. In Peru the most important 
silver mines, those of Potosi, Pasco, and Chota, are 
placed at an immense elevation ; so that, in working 
them, men, provisions, and cattle, must be brought 
from a distance ; but in Mexico the richest of these, 
those, namely, of Guanaxuato, Zacatecas, Tasco, 
and Real del Monte, are at moderate heights, and 
surrounded by cultivated fields, towns, and villages. 
There are few rivers of consequence in the country, 
the Rio Bravo del Norte and the Rio Colorado being 
the only ones of any magnitude. The former has 
a course of 1767 miles, the latter of 863; but these 
streams flow in the least cultivated parts of the 
country, and can have little influence in a commer- 
cial point of view until colonization shall extend to 
their shores. In the whole equinoctial part of New 
Spain there are only small rivulets, of which very 
few can ever become interesting to the merchant. 
The numerous lakes, the greater part of which 
appear to be annually decreasing in size, are the 
remains of immense basins of water that formerly 
existed on the elevated plains. Of these may be 
mentioned the lake of Chapala, nearly 2067 square 
miles in extent; those of the valley of Mexico, 
~ which comprehend a fourth part of its surface; that 
of Patzcuaro in Valladolid; and, finally, the lakes 
of Mexitlan and Parras in New Biscay. 
The interior of New Spain, and especially a great 
part of the elevated table-land of Anahuac, is arid 
