CHANGE OF R’ VEE-COURSES. 
13 
Tinaco, the Guanarito, and the Chilua, falls into the Portu- 
guesa, which is a branch of the Apure. It is a remarkable 
phenomenon, that by a particular position of the ground, 
and the lowering of the ridge of division to south-west, the 
Itio Pao separates itself from the little system of interior 
rivers to which it originally belonged, and for a century 
past has communicated, through the channel of the Apure 
and the Orinoco, with the ocean. What has been here 
effected on a small scale by the hand of man, nature often 
performs, either by progressively elevating the level of the 
soil, or by those falls of the ground occasioned by violent 
earthquakes. It is probable, that in the lapse of ages, 
several rivers of Soudan, and of New Holland, which are 
now lost in the sands, or in inland basins, will open for 
themselves a course to the shores of the ocean. We cannot 
at least doubt, that in both continents there are systems of 
interior rivers, which may be considered as not entirely 
developed ; and which communicate with each other, either 
in the time of great risings, or by permanent bifurcations. 
The Rio Pao has scooped itself out a bed so deep and 
broad, that in the season of rains, when the Cano Grande de 
Cambury inundates all the land to the north-west of Guigue, 
the waters of this Cano, and those of the lake of Valencia, 
flow back into the Rio Pao itself; so that this river, instead 
°i_ adding water to the lake, tends rather to carry it away. 
We see something similar in North America, where geo- 
graphers have represented on their maps an imaginary chain 
of mountains, between 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 Mississippi ; and it is practicable 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 analo- 
gous facts appear to me well worthy of the attention oi 
hydrographcrs . 
Idle land that surrounds the lake of Valencia being en- 
tirely flat and even, a diminution of a few inches in the level 
ol the water exposes to view a vast extent of ground covered 
1 i’ ertilu mu< ^ alM *- 0, 'g a,l ie remains.* In proportion as 
the lake retires, cultivation advances towards the new shore. 
* This 1 observed daily in the Lake of Mexico. 
