Topographical Sketch of the State of New- York. &7 



Art. XI. Topographical Sketch of the State of New- York, 

 designed chiefly to show the general Elevations and Depressions 

 of its Surface. By Joseph Hknry. 



The Topography of the state of New- York, viewed either in re- 

 lation to that of the continent of North America in general, or 

 only in reference to the space included within its own political 

 boundaries, presents many interesting and peculiar features. 



The two great lakes, and their outlets, forming a natural boun- 

 dary on the north and west ; the continued chain of water com- 

 munication of the Hudson and Lake Champlain, along the whole 

 eastern section ; the connected series of smaller lakes in the inte- 

 rior, together with several large streams which rise in the middle 

 of the state, and pass through its southern boundary ; all give to 

 the surface of New- York a diversity of aspect, and a facility of 



try, and perhaps not surpassed by any of equal extent on the sur- 

 face of the globe. 



The eastern portion of the United States, designated by geogra- 

 phers as the Atlantic slope, is separated from the central part, or 

 the great valley of the Mississippi, by a marked natural division, 

 consisting of a continuous swell or ridge of land extending from 

 Alabama to the south shore of Lake Ontario. This ridge is the 

 true water shed of: the country, and determines the course of the 

 rivers falling into the Atlantic on the one side, and those into the 

 Mississippi on the other. It has a mean height of about 3000 feet ; 

 and cannot be crossed at_any point south of the state of New- 

 York, by an elevation of "less than two thousand feet above the 

 ocean. Upon the acclivities of this ridge are based an indetermi- 

 nate number of spurs, lulls, and collateral subordinate ridges, 

 which often rise to a much greater height than the crest of the 

 water shed. These subordinate ranges are not continuous, but 

 are often cut through by the Atlantic rivers : They have, however, 

 nearly the same direction as the main ridge ; and in passing 

 through North-Carolina and Virginia, assume the form of four 

 principal ranges, nearly parallel to each other. The three west- 

 ernmost of these mingle together in the northern part of Pennsyl- 

 vania, and form a mountain chain, which diverges to the east from 

 the great water shed, and in passing through the state of New- 

 York, occupies the space between Seneca lake and tlio Hudson 

 jivcr. At first sight, it appears to terminate at the valley of the 



