METEOROLOGY. 501 



Bpeculation on foot for draining the valley completely by cutting a 

 canal and letting off the water. Further proof of the fact which 1 

 am urging is obtained in another way. It is not difficult to show, 

 that lakes in the immediate vicinity of those that have shrunk most 

 remarkably, but around which no destruction of the forest has taken 

 place, have undergone no change in their level. The lake of Tota, 

 situated at no great distance from the valley of Ubate, at an eleva- 

 tion that must approach 13,000 feet above the level of the sea, in a 

 region where vegetation has almost entirely disappeared, has pre- 

 served its pristine level unaltered. The lake is nearly circular ; 

 and Piedrahita, in 1542, gives it two leagues in breadth. It is sub- 

 ject to violent storms, which render its navigation dangerous ; and 

 even travelling along its banks, from the particular circumstances in 

 which the road is situated, with tho .ake on one hand and a perpen- 

 dicular cliff upon the other, is not without risk. In 1652, the road 

 passed as it does at present, the water laving the foot of the same 

 rocks, and its level having suffered no change, any more than the 

 sterile country which surrounds it. 



I shall conclude what I have to say on the lakes of South America 

 by speaking of that of Quilatoa, because it has been made the subject 

 of accurate observations sufficiently remote from one another — 1740 

 and 1831. 



Living at Latacunga, a town situated at no great distance from 

 Cotopaxi, the traveller is sure to hear of the wonders of the Laguna 

 da Quilatoa. From time to time this lake, it is said, casts forth 

 flames which set fire to the shrubs and withered grass that grow 

 upon its banks, and frequent detonations are heard, the sound of 

 which extends to a great distance. M. de la Condamine, in 1738, 

 visited this lake, which he found of a circular form, and about 1278 

 feet in diameter ; on the 28th November, 1831, 1 also visited the 

 Lake of Quilatoa. It cannot be better compared to any thing than 

 to the crater of a volcano filled with water ; I found it nearly 13,000 

 feet above the level of the sea, in the cold region, therefore ; and 

 indeed it is surrounded with immense pastures ; but the information 

 which I obtained from the shepherds in the neighborhood of the Lake 

 of Quilatoa, dissipated all that was marvellous in its history ; they 

 had never seen any flames issue from its bosom, they had never 

 heard any detonations ; in short, I found the lake as M. de la Con- 

 damine appears to have found it, every thing having remained for 

 nearly a century without change. 



The study of the lakes which are so common in Asia, would 

 probably supply conclusions similar to those deduced from observa- 

 tions made in South America, viz., that the waters which irrigate a 

 country diminish as the forests are cleared away, and as agriculture 

 extends. The recent labors of M. de Humboldt, which have thrown 

 so much new light upon this quarter of the world, appear to leave 

 no doubt upon the subject. After having shown that the system of 

 the Altai is about to lose itself by a succession of slopes in the 

 steppes of Kirgiz, and that consequently the Ural chain is not con- 

 nected with that of the Altai, as was generally belioved, this celebrated 



