CHAPTER III.

Climate-variety under the same latitude-rains-general salubrity-fertility of the soil-corn, fruits-cattle —general improvement in agriculture—influence of mines on agriculture-habits of Indian cultivators.

HAVING traced the physical outline of the country, and described the inequalities of its surface, we shall proceed to point out the effect of these inequalities upon its climate, and to give some account of the state of cultivation. We shall confine ourselves to a few general and important facts. Details of natural history do not fall within the compass or the purpose of this work; but it is impossible to form an exact idea of the territorial riches of a country without knowing the form of the mountains, the height of the great plains of the interior, and the temperature of the regions in which there are (if we may so express ourselves) successive strata of climate.

If we take a general view of the whole surface of the kingdom of Mexico, we shall see that two-thirds are situated under the temperate, and one under the torrid zone. The former part contains 738,000 square miles, and includes the Provincias Internas de la Commendancia-general, a district thinly

peopled. The latter, containing 324,000 square miles, enjoys a climate which is cool or temperate, rather than sultry. It is well known that the climate of a country depends, not only on its distance from the pole, but also on its elevation above the level of the sea, proximity to the ocean, configuration, and many other local circumstances. The interior of the viceroyalty of Mexico forms an immense plain, elevated from 6000 to 8200 feet above the level of the sea. The country lying between the capital of Mexico and the port of Vera Cruz may be divided into three districts or zones, the climate of which depends on their elevation. The first of these, called by the natives terras calientes, comprehends all the country on the coast, nearly the whole intendancy of Vera Cruz, the southern regions of the intendancies of Mexico, Valladolid, and La Puebla. It is all flat country, intersected by inconsiderable hills. The mean temperature of these plains is about 77° of Fahrenheit's thermometer, that is to say, 15° or 16° higher than the temperature of Naples. They produce sugar, indigo, cotton, and bananas, in abundance, but are extremely unhealthy. They are liable to great and sudden changes of temperature, and are frequently visited by yellow fever.

The next region, called terras templadas, lies on the declivity of the Cordilleras, at the height of from 4000 to 5000 feet, and enjoys a perpetual spring. The temperature is soft and equal, never varying

more than 4° or 5°: the mean heat of the whole year is from 68° to 70°. This region is, however, extremely liable to fogs from the sea.

The third zone, the terras frias, comprehends the table-lands, which are elevated more than 7200 feet above the level of the sea. Although they are known under the name of terras frias, the thermometer has very rarely been known to be down to the freezing point: in the coldest season the mean heat of the day is from 55° to 60°. In summer the thermometer in the shade does not rise above 75°. The general mean temperature of the whole vast table-land of Mexico is 62°. It is equal to the temperature of Rome. This is a sufficient proof that the words hot and cold have no positive value. The table-lands higher than that of Mexico have a very rough and disagreeable climate, even to the feelings of a native of a northern latitude. The winters are not severe, but there is a total absence of that transient summer which has a peculiar beauty in high latitudes.

These general considerations on the physical division of New Spain are extremely interesting in a political point of view. In France, and even in the greatest part of Europe, the cultivation of the soil depends almost entirely on geographical latitude; but in the equinoctial regions of Peru, New Grenada, and Mexico, the climate, productions, and aspect of the country, are solely modified by the elevation of the soil above the level

of the sea.

The influence of geographical position

is absorbed in the effect of this elevation.

There are only two seasons known in the equinoctial region of Mexico even as far as the 28th degree of N. latitude; the rainy season (estacion de las aguas), which begins in the month of June or July, and ends in the month of September or October, and the dry season (el estio), which lasts eight months, from October to the end of May. The first rains generally commence on the eastern declivity of the Cordillera. The formation of the clouds, and the precipitation of the water dissolved in the air, commence on the coast of Vera Cruz. These phenomena are accompanied with strong electrical explosions, which take place successively at Mexico, Guadalaxara, and on the western coast. The chemical action is propagated from east to west in the direction of the trade winds, and the rains begin fifteen or twenty days sooner at Vera Cruz than on the central table-land. Sometimes we see in the mountain, even below 6600 feet of absolute height, rain mixed with hail (gresil) and snow in the months of November, December, and January; but these rains are very short, and only last from four to five days; and, however cold they may be, they are considered as very beneficial to the wheat and pasture lands. In Mexico, as in Europe, the rains are most frequent in the mountainous regions, especially in that part of the Cordilleras which extends from the Pic d'Orizaba by Guanaxuato,

Sierra de Pinos, Zacatecas, and Bolaños, to the mines of Guarisamey and the Rosario.

To the north of 20°, from the 22d to the 30th de

gree of latitude, the rains, which fall only in the months of June, July, August, and September, are very unfrequent in the interior of the country.

The aridity of the central plain, the want of trees, occasioned, perhaps, in a good measure by the length of time the great valleys have remained covered with water, obstruct very much the working of the mines. These disadvantages have augmented since the arrival of Europeans in Mexico, who have not only destroyed without planting, but in draining great tracts of land have occasioned another more important evil. Muriate of soda and lime, nitrate of potash, and other saline substances, cover the surface of the soil, and spread with a rapidity very difficult to be explained. Through this abundance of salt, and these efflorescences, hostile to cultivation, the table-land of Mexico bears a great resemblance in many places to Thibet and the saline steppes of central Asia. In the valley of Tenochtitlan particularly, the sterility and want of vigorous vegetation have been sensibly augmenting since the Spanish conquest; for this valley was adorned with beautiful verdure when the lake occupied more ground, and the clayey soil was washed by more frequent inundations.

Happily, however, this aridity of soil, of which we have been indicating the principal physical causes,