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water has sensibly diminished. The lake of Tezcuco, the finest of the five lakes, which Cortez in his letters habitually calls an interior sea, receives much less water from infiltration than iq, the sixteenth century. Every where the clearing and destruction of forests have produced the same effects. General Andreossi, in his classical work on the Canal dn Midi, has proved that the springs have diminished around the reservoir of St. Feneol, merely through a false system introduced ill the management of the forests. In the province of Caraccas, the picturesque lake of Tacarigua * has been drying gradually up ever since the sun darted his rays without interposition on the naked and defenceless soil of the vallies of Aragua.
But the circumstance Which has contributed the most to the diminution of the lake of TezCuqq is the famous open drain, known by the name of the Desague real de Ilueliuetoca, which We shall afterwards discuss. This cut in the mountain, first began in 1607 in the form of a subterranean tunnel, has not only reduced within yery narrow limits the two lakes in the northern jjart of the valley, i. e. the lakes of Zumpango (Tzompango) and San Christobal; but has also prevented their waters in the rainy season from flowing into the basin of the lake of Tezcuco.— These waters formerly inundated the plains, and purified a soil strongly covered with carbonate and muriate of soda. At present, without settling into pools, and thereby increasing the humidity of the Mexican atmosphere, they are drawn off by an artificial canal into the river of Panuco* which flows into the Atlantic Ocean.
* New islands appear in it from time to time from the diminution of water (las aparecidas.)—The lake of Tacarigua, or Nueva Valencia, is 474 metres (1554 feet) elevated above the level of the sea.—(See my Tableaux de la Nature, torn. i. p. 72.
This state of things has been brought about from the desire of converting the ancient city of Mexico into a capital better adapted for carriages, and less exposed to the danger of inundation. The water and vegetation have in fact diminished with the same rapidity with which the tequesquite (or carbonate of soda) has increased. In the time of Montezuma, and long afterwards, the suburb of TIateloIco, the barios of San Sebastian, San Juan, and Santa Cruz, were celebrated for the beautiful verdure of their gardens: but these places now, and especially the plains of San Lazaro, exhibit nothing but a crust of efflorescent salts. The fertility of the plain, though yet considerable in the southern part, is by no means what it was when the city was surrounded by the lake. A wise distribution of water, particularly by means of small canals of irrigation, might restore the ancient fertility of the soil, and re-enrich a valley which nature
appears to have destined for the capital of a great empire.
The actual bounds of the lake of Tezcuco are not very well determined, the soil being so argillaceous and smooth that the difference of level for a mile is not more than two decimetres*. When the east winds blow with any violence, the water withdraws towards the western bank of the lake, and sometimes leaves an extent of more than 600 metres f dry. Perhaps the periodical operation of these winds suggested to Cortez the idea of regular tides ;£, of which the existence has not been confirmed by late observations. The lake of Tezcuco is in general only from three to five§ metres in depth, and in some places even less than one. Hence the commerce of the inhabitants of the small town of Tezcuco suffers much in the very dry months of January and February; for the want of water prevents them from going in canoes to the capital. The lake of Xochimilco is free from this inconvenience; for from Chalco, Mesquic, and Tlahuac, the navigation is never once interrupted, and Mexico receives daily, by the canal of IztapaJapan, roots, fruits, and flowers in abundance.
* 7.874 inches. Trans. f 1968 feet. Trans.
% Journal de Savans for the year 1676, p. 34. The Jake of Geneva manifests also a regular motion, which Saussure attributes to periodical winds.
§ 91 to l6f feet. Trans.
Of the five lakes of the valley of Mexico, the lake of Tezcuco is most impregnated with muriate and carbonate of soda. The nitrate of barytes proves that this water contains no sulphate in dissolution. The most pure and limpid water is that of the lake of Xochimilco, the specific weight of which I found to be 1.0009, when that of water distilled at the temperature of 18° centigrade* was 1.000, and when water from the lake of Tezcuco was 1.0215. The water of this last lake is consequently heavier than that of the Baltic sea, and not so heavy as that of the ocean, which, under different latitudes, has been found between 1.0269 and 1.0285. The quantity of sulphuretted hydrogen which is detached from the surface of all the Mexican lakes, and which the acetite oflead indicates in great abundance in the lakes of Tezcuco and Chalco, undoubtedly contributes in certain seasons to the unhealthiness of the air of the valley. However, and the fact is curious, intermittent fevers are very rare on the banks of these very lakes, of which the surface is partly concealed by rushes, and aquatic herbs.
Adorned with numerous teocallis, like so many Mahometan steeples, surrounded with water and dikes, founded on islands covered with verdure, and receiving hourly in its streets thousands of
» 54° Fahrenheit. Trans.
boats which vivified the lake, the ancient Tenochtitlan, according to the accounts of the first conquerors, must have resembled some of the cities of Holland, China, or the Delta of Lower Egypt. The capital, reconstructed by the Spaniards, exhibits, perhaps, a less vivid, though a more august and majestic, appearance. Mexico is undoubtedly one of the finest cities ever built by Europeans in either hemisphere. With the exception of Petersburg, Berlin, Philadelphia, and some quarters of Westminster, there does not exist a city of the same extent which can be compared to the capital of New Spain, for the uniform level of the ground on which it stands, for the regularity and breadth of the streets, and the extent of the public places. The architecture is generally of a very pure style, and there are even edifices of very beautiful structure. The exterior of the houses is not loaded with ornaments. Two sorts of hewn stone, the porous amygdaloid called tetzontli, and especially a porphyry of vitreous feld-spath without any quartz, give to the Mexican buildings an air of solidity, and sometimes even magnificence. There are none of those wooden balconies and galleries to be seen which disfigure so much all the European cities in both the Indies. The balustrades and gates are all of Biscay iron, ornamented with bronze, and the houses, instead