130 ACCOUNT OF THE 



causes that acted before the retreat of the sea, or by the 

 convulsion which occasioned that event, must have consti- 

 tuted at one period a series of little lakes, which were gra- 

 dually, by tlie action of tlie waters, formed into the present 

 continued and irregular canal. 



2. It has been already stated, that on the south side of 

 the Ohio its tributary streams flow in deeper vallies than on 

 the north. This is obvious from the difference in current, 

 when low, of these two classes of rivers, and from the very 

 different distances at which their waters are rendered stag- 

 nant by the floods of the Ohio, When this river is greatly 

 swollen, the current in the Kentucky river is destroyed near- 

 ly to Frankfort, a distance of forty miles, while that of the 

 Great Miami in this State, a river of almost the same mag- 

 nitude, is not suspended for more than twelve or fifteen. 

 The principal vallies of the north are, however, much wider 

 than those of the south. If they were all fissures originally, 

 those of the south were probably the deepest. The present 

 difference in their width has perhaps arisen from the sides 

 of the former being composed of hard limestone, with but 

 thin inter-laminffi of argillaceous matter, while the rocky 

 strata of the latter are widely separated by friable marl and 

 slate clay. It would appear, that to the south the currents 

 had produced more vertical, in the north more horizontal, 

 attrition. 



3. In the very extensive artificial excavations made into the 

 old alluvial formation at this place, the only aquatic animal 

 remains, either of the river ur the sea, which have been dis- 

 covered, except those detached from the floetz rocks, were 

 the shells of a bivalve, which seems to be a species of Mi/a .• 

 but whether it inhabited the fresh or salt water, I am unable 

 to decide. Hence it would seem that when tliese grounds 

 were deposited, the waters had but few inhabitants. Those 

 of the ocean had withdrawn, and those wliich the river now 

 contains had not yet become its tenants. Whether this be 

 admitted or not, it is certain that the alluvial deposits made 

 at the present day are by no means free from river shells. 



