The valley of the Susquehanna proper presents an area of inland navigation or about 20,000 square miles.
If we turn our eye to the whole basin of the Susque hanna, and consider it geographically, we have before us a mighty link, which connects the three great river sys tems of North America—those of the Gulf of AIexico, St. Lawrence, and Atlantic Ocean proper. The natural facilities it presents to channels of inland navigation will be shown in the sequel, with the relative elevation of its mountain valleys, and the obstructions opposed to artificial water routes.
If we examine this basin geologically, we find its gene ral physiognomy, in a very remarkable manner, com manding our attention. NVe have in this basin all the formations which the world affords, from the highest class of primitive rocks, to the most recent alluvion. And we have all those formations on an immense scale. But the circumstance arising out of this geological struc ture, most worthy of our attentive observation, is. that the courses of the waters, or their fitness, or unfitness for navigation, appears to be totally independent of the rock formations. It appears, also, that, although the mere windings of the streams are influenced by the mountain ridges, that their general courses towards the recipient, into which the waters are discharged, have no dependence upon either the mountains or rock forma tion. The latter character the Susquehanna ba.dn par takes, in cotnmon with its three contiguous Atlantic basins, those of Roanoke, Delaware, and Hudson.
These very important facts prove how little we are advanced in a correct view of any of these basins, in a navigable point of view, by the most minute knowledge of the relative position of the mountains, the extent and relative position of the different formations, or, more, that of the courses of the rivers themselves. Falls, in the proper sense of the term, are rare in any of the At lantic rivers. What are usually denominated falls are in reality rapids ; but those, in respect to either their posi tion or magnitude, have but an incidental connexion with the rnountain ridges. In most instances, where the rivers do pass the mountains, rapids occur ; but this co incidence is by no means universal. The rivers, in a number of the mountain gaps, present an intervening smooth sheet of water. This is remarkably the case
with the Juniata, below Bedford, and with the Lehigh, at its passage through the Kittatinny range. The real fall of the water, in its descent from the mountain valleys to the level of the tides, can in no instance be even tolerably correctly estimated by a comparison with its course through the mountains. Every stream, to be well under stood, must be surveyed separately, and considered a whole in itself.
Before quitting the general review of the basin of the Susquehanna, we may remark, that the main volume of that river, from its source to the Atlantic, receives all its large tributary streams from the right, and serves as a common recipient, lying along the base of an inclined plain, extending from the 37th to the 42d degree of north latitude. It will be seen by inspection, that this feature is also prominent in the physiognomy of the Potomac, Delaware, and the Hudson.
The Delaware basin, intervening between that of Sus quehanna and that of the Hudson, extends about 250 miles from north to south, with a mean width of 60 miles, ex tending ovcr an area of 15,600 square miles. The Dela ware rises by two branches in the Catsbergs, draining the angle between the Susquehanna and Schoharic branch of Alohawk. The sources of the Delaware flow south-west, by comparative courses, 50 miles, through Delaware county, in New York, unite at the north-east angle of Pennsylvania, and turn at right angles to a course of south-east ; following the latter direction, by com parative comses, 70 miles, to the north-west angle of New Jersey, and thc base of the Kittatinny mountain; again turning with the mountain to the south-west, fol lows that course along its !rase, by comparative courses, 40 miles, to the mouth of Broadhead creek, where the river again turns, and passes the Kittatinny mountain. The general physiognomy of the Susquehanna and Dela ware, every where remarkable, is in no other place so striking as in the valley between the Kittatinny inoun tain and the continuation of the Blue Ridge, below Easton and the mouth of the Lehigh. I have already noticed that reach of the Susquehanna from the mouth of the West Branch to that of the Juniata. A corres ponding reach in the Delaware extends across the Kit tatinny valley, to where the river pierces the south-cast mountain.