Drainage ^Features of the Upper Ohio Basin. 261 



The evidence seems to us very strong that the ox-bow at 

 Franklin, the old channel northeast of TJtica, and the ox-bow 

 north of TJtica are remnants of the same old meandering 

 stream leading northwesterly. The fact that the rock floor 

 in the ox-bow north of Utica is 70 feet below the deepest deter- 

 mination of the old channel where it left the present Alle- 

 gheny, renders it highly improbable, if not impossible, that it 

 was formed by a stream discharging toward the Allegheny. 

 It is even lower than the present rock bottom of the Alle- 

 gheny, notwithstanding all the erosion the latter is believed to 

 have suffered since the deposition of the early glacial gravels. 

 It is highly probable, therefore, that we have, in these aban- 

 doned valleys, a continuation of the old middle Allegheny. 

 An inspection of the general configuration of the old channel, 

 as shown on map 3, will lend support to the force of these 

 considerations. 



A comparison of the old gradation-planes on the middle 

 Allegheny with the like gradation-plane of the lower Alle- 

 gheny at the mouth of the Clarion, brings out the significant 

 fact that the rock bottom in the Franklin ox-bow stands 

 about 40 feet below the rock bottom of the ox-bow above 

 Parker, just below the mouth of the Clarion. This is J^O 

 miles distant down stream (see tig. 4). If we compare the 

 lowest point found on *the old gradation-plane near Parker 

 with the bottom of the deepest well in the Franklin ox-bow 

 (which did not reach bottom), it is still 10 feet higher. If we 

 compare their respective heights above the present river, the 

 bottom of the Franklin ox-bow is not more than 35 feet, 

 while that of Parker is 150 feet above the stream. Granting 

 as probable that the old stream had a less fall than the present 

 one, it still seems impracticable to refer the Franklin ox-bow 

 and the gradation-planes and shelves associated with it, to the 

 same stream that made those at and below the mouth of the 

 Clarion at so much higher levels. 



An additional point in evidence that the Allegheny has had 

 its upper drainage basin enlarged by additions is found in a 

 comparison of the size of the trench cut in the old fluvial floor 

 of its lower course with that of the corresponding trench of 

 the tributaries. For instance, on the Hedbank river, which 

 enters 22 miles below the Clarion, accurate data are obtain- 

 able, since the railway follows its valley for 70 miles and has a 

 grade nearly coincident with the stream, and but a few feet 

 (20-40) above it. The profile of this railway (see fig. 2), 

 brings out the significant fact that the stream has a much 

 more rapid fall in the lower 20 miles of its course than above 

 that point, which is the reverse of the normal law of streams. 

 The average fall for this 20 miles is nearly 12 feet per mile, 

 while for the next 20 miles above, or even 50 miles above, the 



