m 



the great lakes of Canada and the country of 

 the Miamis. At the time of floods, the waters 

 flowing" into the lakes communicate with those 

 which run into the Missisippi ; and it is practi- 

 cable to proceed by boats from the sources of 

 the river St. Mary to the Wabash, as well as 

 from the Chicago to the Illinois*. These ana- 

 logous facts appear to me well worthy of the 

 attention of hydrographers. 



The land that surrounds the lake of Valencia 

 being entirely flat and even, what I daily ob- 

 served in the lakes of Mexico takes place here ; 

 a diminution of a few inches in the level of the 

 water exposes a vast extent of ground covered 

 with fertile mud and organic remains. In pro- 

 portion as the lake retires, the planters advance 

 toward the new shore. These natural desicca- 

 tions, so important to the colonial agriculture, 

 have been eminently considerable during the 

 last ten years, in which all America has suffered 

 from great droughts. Instead of marking the 

 sinuosities of the present banks of the lake, I 

 have advised the rich landholders in these 

 countries, to place columns of granite in the 

 basin itself, in order to observe from year to 

 year the mean height of the waters. The Mar- 

 quis del Toro has undertaken to put this design 

 into execution, employing the fine granite of the 



* Drake, Picture of Cincinnati, 1815, p. 222. 



