On each coast, the low grounds are intersected by very inconsiderable hills : but, in the central plain, be tween the town of Mexico and the city of Cordova, there are groupes of lofty mountains, equal in height to any in the new continent, particularly those of Popoca tepetl, i. e. the smoke mountain, Iztaceihuatl, i. e. the white woman, Citlaltepetl, i. e. star mountain or the Pic d'Ouzaba, and Nauhcampateptl, i, e. square mountain, or the Cofre de Perote, which are respectively 17,716, 15,700, 17,371, and 13,414 feet above the level of the sea. To the north of latitude 19° the Cordillera takes the name of Sierra Madre, and runs to the north-west. Be yond the city of Guanaxuato, in latitude 21°, it becomes of an extraordinary breadth, and divides into three branches. Of these the most eastorn runs in the direc tion of Charcas, and loses itself in the new kingdom of Leon. The western branch, occupying part of the in tendancy of Guadalaxara, sinks rapidly after psssing Bolanos, and stretches to the banks of the Rio Gila, but acquires again a considerable height under the 30th paral lel, near the Gulf of California, when it forms the moun tains de la Pimeria Alta, celebrated for the gold washed down from their sides. The third branch, which may be considered as the central chain of the Mexican Andes, occupies the whole extent of the intendancy of Zacate cas, and may be traced to the Sierra de los Mimbres, -west of the Rio Grande del Norte, thence traversing New Mexico, and joining the Crane mountains and Sierra Verde. This central branch is the crest which divides the waters between the Pacific and Atlantic oceans ; and it was a continuation of this branch which Fidler and Mackenzie examined under the 50° and 55° of north latitude.
There are five burning volcanos in Mexico, namely, Ouzaba, Popocatepetl, Tustla, Jorullo, and Colinia ; hut earthquakes and eruptions arc not frequent. The former are chiefly experienced on the coast of the Pa cific, and in the environs of the capital, but never pro duce such desolating effects as in the provinces of Gua timala,Cumana, Quito, and Lima.
In New Spain there is a great want of water, and of navigable rivers. The great river of the north (Rio Bravo del Norte) and the Rio Colorado, are the only rivers distingushed by the length of their course, and their volume of water. The first of these runs through a course of 512 leagues from its source in the moun tains of Sierra Verde, east from the lake of Timpano gos, to its mouth in the province of New Santander in the Gulf of Mexico ; ancl the latter flows 250 leagues from its origin in a hilly tract, about 13 leagues west from that of the del None, till it falls into the Gulf of Cali fornia. This last mentioned river is formed by the tinion of the Zaugananes and the Nolnijoa ; and itself forms a junction NI ith the Gila about the :33d parallel or moth latitude. In the southern part of Mexico, the narrow form of the continent prevents the collection of a great mass of water, and the rapid declivity of the Cordillera abounds in torrents rather than rivers. Those which are most adapted for navigation are, the Guasacualco and the Alvarado to the south-east of Vera Cruz ; the Moetezuma, which carries the waters of lake Tenoch titlan to the Pantie° ; the Zacatula, at a small sea-port of the Pacific Ocean on the frontiers dividing the inten dancies of Mexico and Valladolid ; and the great ricer of Santiago, formed by the junction of the Lerma and Laxas, and falling into the Suuth Sea et the port of San Blas.
The lakes, with which Mexico abounds, are consi dered as merely the remains of immense basins of wa ter, which appear to have formerly existed on the high plains of the Cordillera, and al e said to be annually di minishing. The most remarkable are the great lake of
Chapala in New Gallicia, nearly 160 leagues square ; the lakes in the valley of Mexico, which cover a lourth part of the (Usti ict ; the lake of Potacuaro in the inten dancy of Valladolid, which is accounted one of the most picturesque situations in the world ; the lakes of titian and Parras in New Biscay; and the. great lake of Nicaragua, about 200 miles in circumference, in the kingdom of Guatimala.
The mineral productions of this country form one of the principal sources of its wealth, and are found in a great variety of rocks and forms throughout the range of the Cordilleras ; but the districts of Guanaxuate, Zacatecas, and Catorce are the most abundant, and sup ply more than one half of the whole amount of precious metals exported from the country. The fanner alone yields one-fourth of the silver of Mexico, and one-sixth of the produce of all America. The richest mines of New Spain, arranged according to the quantity of metal which they yield, are Guanaxuato, in the intendancy of the same name. Catorce, in the intendancy of San Louis Potosi. Zacatecas, in the intendancy of the same name. Real del Monte, in the intendancy of Mexico. Bolanos, in the intendancy of Guadalaxara. Guarisamey, in the intendancy of Durango. Sombrerete, in the intendancy of Zacatecas. Casco, in the intendancy of Mexico.
Batopilas, in the intendancy of Durango. Ziniapan, in the intendancy of Mexico.
Fremillo, in the intendancy of Zacatecas.
Ramos, is the intendancy of San Louis Potosi ; and Pavia), in the intendancy of Durango.
The Mexican mines are considered as forming eight groupes, Ste. and arc almost all placed either on the ridge or the western slope of the Cordillera of Anahuac ; and it is a remarkable circumstance, that the tract which yields the greatest quantity of silver, between 21 and 24i degrees of latitude, corresponds, in distance from the equator, with the district of greatest metallic wealth in Peru. The mean annual produce of the whole is 2,500,000 mares of silver, about ten times more than what is furnished by all the mines of Europe ; and 700 mares of gold, about an equal quantity to what the Eure pcan mines afford. Yet the ore is by no means remarkably rich; and the mean produca of the whole vein of Gu anaxuato is four ounces of silver per quintal of minerals. The mining operations also are carried on at great ex pense, and not always in the most economical manner. In the mine of Valenciana, one of the richest in Guan axoato, there is an administrator with a salary of 2500/. sterling ; an overseer under him, with several under overseers, and nine master miners, with 1800 workmen labouring in the interior of the mine. The expense of the powder alone has often amounted to 1 6,668/., and of the steel for implements to 62501. A new draught pit, 87 feet in circumference, and which was to reach to the enormous perpendicular depth of 1685 feet, was ad vanced, (when seen by M. Humboldt, in 1803,) to the depth of 603 feet, and was estimated to cost a million of piastres, and to require the labour of twelve years before it could be completed. The American miners have learned little from those of Europe since the I cen tury, except the blowing with powder; and, though the court of Madrid has frequently attempted to introduce into the colonies the use of the more recent improve ments in mechanical and chemical science, yet, as the mines are considered as the property of individuals, the government has no influence in directing the operations.