Topographical Sketch of the State of New- York. 9T 



No. VIII. 



Table of Ascents and Descents from Lake Ontario, along die 

 valley of the Genessee River, to the mouth of Black Creek in 

 Allegany County, and thence to Olean, on the Allegany River, 

 along Oil and Black Creeks. 



No. IX. 



Table of Ascents and Descents from the mouth of Oak Orchard^ 

 Creek, on Lake Ontario, in nearly a direct line to Olean on the 

 Allegany, by the route of Batavia, the Tonnewanta Creek, Lime 

 Lake, and the valley of Ischua Creek. 





Lake Ontario, at the mouth of Oak Orchard creek, 1 j 







T«w^ta|^kti?^Uvia/ Jl7| 













Limelake,t ' * ^ ^ 











1409 



It is evident from these tables, that the mountain system occu- 

 pies the entire width of the southern part of the state, between 

 the Hudson and Lake Erie. The section given in Table No. 1, 

 exhibits a mean elevation, after the first 13 miles from the Hudson, 

 of 1400 feet, and presents no height less than 935 feet, except at 

 its extremities, and in the two places where the survey descends 

 into the deep ravines in which are situated Cayuga and Seneca 

 lakes. If this section had passed a few miles to the south of the 

 head of Seneca lake, the lowest point would have been 890 feet, 

 which is the highest part of the bottom of a valley extending from 

 this lake to the Chemung river. The mean elevation of the sev- 



13 



