The Tioga drains a valley or about 90 miles by 30 mean width, or 2700 square miles; comprising in New York all Steuben, and a part of Alleghany, Livingston, Yates, and Tioga counties; and in Pennsylvania a part of Potter, Tioga, and Bradford counties.
Combining the two sections of this northern section of the valley of Susquehanna, we have a physical section extending from the eastern sources of Unadilla to the western of Tioga, 180 miles, with a mean width of about 48, and area 8640 square miles, of which 1040 are in Penn sylvania.
The features of this region, and its lines of con nection with the adjacent vallies, present some very interesting phenomena to the geographer and states man. On the sides towards the Schoharie and Mohawk, where the Catsbergs and other elonga tions of' the Apalachian chains form the dividing ground between the Susquehanna and Hudson wal lies, there exists no intermediate gaps except at great comparative elevation. On the contrary, be tween the sources of Chenango and those which flow nothwards into the Ontario basin, deep vales extend from the respective sources through the in tervening ridges. It is very difficult in many places to determine the point where the waters separate. The face of the country is hilly to an extent which gives a mountainous appearance, and yet the inter mediate valleys are many of them broad and marshy. Very striking examples exist in Courtlandt and Madison counties. These deep traverse wallies are not, however, peculiar to the head sources of Che nango; one of the most remarkable amongst them extends from the Tioga at Elmira, to the head of Seneca Lake.
The mean water level at Tioga Point is 723 feet above the Atlantic Ocean; and from the Point to Newtown or Elmira on Tioga river the rise is 103 feet, giving to the water level at Newtown a com parative water level of 826 feet elevation. Though the hills are very high in the vicinity of Newtown, the natural valley stretching from the Tioga river northwards to the head of Seneca Lake, has a rise of only 59 feet above the former, though the de clivity on the northern side towards the Seneca has a descent of 445 feet in 10 or 11 miles. The inter mediate summit level is 885 feet above the surface of the ocean, and is the lowest gap through which a canal could be formed to connect the Atlantic and interior waters of the United States, from the valley of the :Mohawk to Lower Georgia. A single glance on a map of this physical region, will serve to exhibit the singular natural facilities afforded to na vigation, or to the creation of artificial water chan nels of intercommunication, by the depression of the vallies between them, and the approximation of the St. Lawrence lakes to the northern streams of the
Susquehanna.
Though so far advanced towards as to be at the extreme eastern sources within 40 miles from tide water in Hudson river, the entire northern section of the Susquehanna valley is on the interior floetz or secondary formation, and has a discharge from this formation not from but directly into the Appa lachian system.
A. very erroneous opinion may be here noticed and corrected. The Appalachian system of moun tains is commonly regarded as a dividing barrier between river source. This is so far from being the real state of nature, that the mountain chains have in no one place in the United States distinctly in fluenced the general course and recipient of any river; the bends, or the inflections of the streams if viewed on a large scale, appear to be either at right angles or parallel to the chains, and give to river physiognomy a family similarity which must greatly interest the attentive observer; but the system of mountains traverses the Atlantic and Mississippi plains obliquely. It is from such a physical structure of the continent that the Susque hanna is seen pouring down from an elevation above that of the base of the mountains, against which its various branches impinge; and that these branches have in the course of time torn passages through the river rocks, and their waters gradually uniting, at length reach the level of the Atlantic tides, and gradually mingle with the waters of the Atlantic Ocean. This contest between the appa rently stable mountains, and the equally apparently fleeting rivers, which began, it is most probable, with the creation, is far from being terminated. It is a feature in physical geography in a high degree, not simply favorable to their actual construction, but to excite original conceptions of canals. The rivers have, during accumulated centuries, done that which man would without their aid never dared even the conception. The rivers rising be yond have fallen with steady and irresistible weight on the mountain sides, and torn them to their bases, and given to human beings, and the fruits of their labour, a free passage:—but we must return to our subject.