VALLEY OF THE OHIO. 131 



4. That the valleys of this quarter are not the work of 

 causes which have acted regularly and unremittingly ever 

 since tlie recession of the sea, hut that there was a particular 

 and distinct period of evravatinn, is rendered still more proba- 

 ble, by the fact, that their declivities are every where cover- 

 ed with a body of loam and soil: For while the causes which 

 produced these slopes continued to act, it is im|)ossible that 

 mould or any loose matter should have been accumulated 

 upon them. 



5. What length of time has elapsed since the final de- 

 scent of tlie ocean into its new bed, since the rivers com- 

 pleted the lateral excavation of their vallies, were reduced 

 to their present size, and began to deposit the low and recent 

 bottoms, I am not in possession any of data for determining. 

 An accurate survey by us of those grounds, of the imme- 

 diate and rocky channels of the streams, of the incomplete 

 and increasing taluses of our hills, and of the vegetable mould 

 which overspreads the face of the country, would lurnisli to 

 a succeeding generation some important facts for an esti- 

 mate of this kind. From the rate of advancement of the 

 dozens and natural sand level which border the southern 

 shores of Michigan, and perhaps some of the other lakes, 

 conclusions equally certain will hereafter, in all probability, 

 be drawn.* By a reference to the Chart, you will perceive 

 the lateral extent and various elevations of the alluvial for- 

 mation at this place. You may suppose the section to be 



* I do not know that these downs have been mentioned by any traveller or 

 writer. I am informed by my friend Mr. William Harris, who was lately 

 employed under the (Jirectinn of the Surveyor General of the United States, 

 in running the northern boundary line of this State, that they are found 

 along the south eastern border of the lake for thirty or forty miles. In some 

 places they extend two or three miles from the head. They are very nume- 

 rous, of various shapes and sizes, and grouped in such a manner as to form 

 basins or concavities, some of which are filled with water. Not a single rivu- 

 let flows ftom among them. There is very little soil spread over any of these 

 hillocks, and partofthcm are quite destitute of vegetation. Others are thinly 

 covered with small pine and oak trees. It is possible that this formation m«y 

 have ceased growing, and that it cannot therefore serve as a natural chrono- 

 meter. 



