OF DENISON UNIVERSITY. I7 



and sand whirled along by the rushing water which in the last 200 

 yards of this rocky bed has a fall of 19 feet. Suddenly the turbulent 

 stream comes to rest in a quiet pool which has a depth near its upper 

 edge of about 80 feet. The right bank continues its course as an un- 

 broken bluff; but the left bank abruptly terminates with a sharp anvil- 

 like point projecting into the deep water. On crossmg over, it is seen 

 that the upper edge of the pool, on the northern side, is some distance 

 above this point, with a muddy shore in which no limestone is appa- 

 rent. This shore gradually curves around toward the east until it 

 forms a bank to the creek parallel to that on the south side. Climb- 

 ing the gravel hills to a point north of H, the traveler sees to the west- 

 ward conical and roof-like hills, whose smooth-flowing outlines show 

 them to be of drift material, stretching away to the bend just below 

 Rattlesnake which he had left some hours before ; and he further sees 

 that they appear to cross at the points where he had lost the limestone 

 on his way down. Thorough examination, involving many miles of 

 tramping to and fro, convinces him that Rattlesnake is flowing in a 

 pre-glacial valley which was filled with drift from the junction of Paint 

 creek to this deep pool at Rapids Forge H ; and that after seeking 

 outlets in various directions as shown by abandoned channels and mi- 

 nor terraces it finally escaped along its present crooked way, regain- 

 ing its former bed by cutting out the limestone which had made its 

 southern boundary, washing down-stream the gravel that it found fill- 

 ing the present pool and making with it a dam which retains the water. 

 He finds also, that the beds of both Rocky Fork and that portion of 

 Paint creek above the mouth of Rattlesnake have been eroded in 

 post-glacial times. 



Somewhat more than a mile below the pool at Rapids Forge, the 

 rugged hills on the south cease and in their stead appear conical knolls 

 which cause the observer to rub his eyes and wonder if he has been sud- 

 denly transported to the region of Omaha ; for at no nearer point will he 

 find such remarkable resemblance to the Missouri river bluffs. Next, 

 he sees a valley opening from the south, and then reappear the hills 

 capped with Waverly sandstone such as he had seen above ; but they 

 are farther away from him. Following the road along the creek bank 

 he soon approaches their foot ; and now the hills on the north side 

 have receded, while the creek, making a salient angle, seems bent on 

 following them. Leaving the road, which continues in nearly a 

 straight course and following the creek to the Falls G, he finds a 



