.^02 METEOROLOGY. 



geographer shows, that precisely in the situation where the Alghinic 

 mountains are usually set down, a remarkable region of lakes com- 

 mences, which extend into the plains that are traversed by the Ichim, 

 the Omsk, and the Obi.* It would appear that these numerous 

 lakes are reniainders as it were of an immense sheet of water, which 

 formerly covered tlie whole of the country, and which had become 

 divided into so many particular lakes by the configuration of the 

 surface. In crossing the steppe of Baraba, in his way from Tobolsk 

 to Baraoul, M. de Humboldt perceived everywhere that the drying 

 up of waters increases rapidly under the influence of tne cultivation 

 of the soil. 



Europe also possesses its lakes ; and we have still to examine 

 them from the particular point of view which engages us. M. de 

 Saussure, in his first inquiries in regard to the temperature of the 

 lakes of Switzerland, examined those which are situated at the toot 

 of the first line of the Jura. The Lake of Neufchatel is eight 

 leagues in length, and its greatest breadth does not exceed two 

 leagues. On visiting it, Saussure was struck with the extent which 

 this lake must formerly iiave possessed ; for, as he says, the ex- 

 tensive level and marshy meadows which terminate it on tlie south- 

 west, had unquestionably been covered with water at a former 

 period. 



The Lake of Bienne is three leagues long and one broad ; it is 

 separated from the Lake of Neufchatel by a succession of plains that 

 were probably inundated. 



Lake Morat is also separated from the Lake of Neufchatel by low 

 and level marshes, which beyond all question were formerly sub- 

 merged. Unijuestionably, adds Saussure, the three great lakes of 

 Neufchatel, Bienne, and Morat, were formerly connected, and formed 

 one great sheet of water. f 



In Switzerland, as in America and Asia, the old lakes, those that 

 may be spoken of umler the title of the primitive lakes, and which 

 occupied the bottoms of the valleys when the country was unculti- 

 vated and wild, have become divided, and now form a variable num- 

 ber of smaller atui independent lakes. I shall wind up the present 

 subject by referring to the observations of Saussure upon the Lake 

 of Geneva, which may be looked upon as the starting point of the 

 admirable works of this distinguished philosopher. 



Saussure admits, that at an e])och long anterior to the times of 

 history, the mountains which surround this lake were themselves 

 submerged ; a great catastrophe let olf this inmicnse collection of 

 water, and by and by the current possessed no more than the bottom 

 of the valley ; the Lake of Ciencva was lormed. 



In merely considering the monuments left by man, it is impossible 

 to doubt that within 1'200 or J 300 years the waters of the Lake of 

 Geneva have gradually fallen in their level. It is evidently upon 

 the levels which have thus been left that the quarter de Kive, and 

 Ihe lower streets of the city of (ieneva have been built. This de 



* HumlM>lcit, Fr:ifjmcn3 .A.^ljitiquo. U 1. p. 40-30. 

 t iSuuKNure, Voyage duns lu.s Alpes, t. ii. chap. 6. 



