OF DENISON UNIVERSITY. 21 



Other south into Ralston's run (which then extended to the Scioto 

 river, the creek having usurped its ancient channel) with a low 

 divide between them. At its narrowest point this is now about looo 

 feet wide. It is evident at a glance that Paint creek should have 

 turned this way on abandoning iis old channel ; for this pass, as 

 shown by its width, was much lower than any other that existed any- 

 where along the southern border. In fact, the stream must have gone 

 through this way for a long time, and with a great volume of water, 

 for it is impossible that so wide a valley could ever have been formed 

 by natural erosion in so short a distance. Thus the whole drainage 

 of Paint creek, reinforced by that from the glacier, would escape 

 through this depression into Ralston's run at a level sufficiently 

 above the Scioto to create a swift current, cutting both the depression 

 and the run wider and perhaps deeper. When the glacier reached its 

 ultimate extension, as a body, within the limits of Ross county, a spur 

 reached entirely across the valley at the point D where the drift is 

 piled to a height of about 120 feet above the present level of the 

 creek. This was from a solid extension and not from a floating berg, 

 because it is pushed up to this level over the solid rock. It would, 

 consequently, shut off the former outlet and form from D southwest- 

 ward a lake which rose until it began to flow over a col or sad- 

 dle-back at the point E into a ravine, tributary to Ralston's run, 

 which had worked its way back until it had to some extent lowered 

 the crest in this range of hills; there was no corresponding ravine on 

 the northern side. The cap rock is Waverly sandstone, full of joints; 

 the underlying shale is so loose it can easily be dug out with a pick. 

 When into such material a lake abundantly fed plunges from a height 

 considerably greater than Niagara, the incoherent rock would disap- 

 pear almost like wax before fire. If the present Ohio was closed at this 

 time, the Scioto was a lake; if the former was open, the latter was a 

 surcharged torrent.* In either case, it was backed up against these 

 hills, forming a body of dead water in which all the rock eroded from 

 the new gorge, along with such material as could be carried by ice, 

 found a resting place, and settled on the drift that had been carried 

 into the same backwater when the larger creek came down from Slate 



*Since the above was put in type investigations in another direction have 

 shown that the flood-height of the Scioto, immediately below Chillicothe, was 

 at least 200 feet above its present bottom. 



