THE CAVES AND POTHOLES AT ROCKWOOD. 245 



far the most common ; a few shells occur, and some fragments of 

 coi'al, especially the genus Favosites. The fragmentary remains of 

 the Orthoceras are seen at some places, but the fossils are neither 

 common enough, nor so well defined as to work up the zeal of young 

 geologists. However, after you have passed over the bridge that 

 leads to some mills and the large quarries and lime kilns near by, you 

 reach localities well suited to arouse enthusiasm in the mind of 

 young students in science. The presence of three large lime kilns 

 demonstrates that this stone j^roduces excellent lime, exceedingly 

 strong and well adapted for building purposes. 



As you pass westward, along by the quarries, you obtain a fine 

 view of the escarpment on both sides of the so called river and grand 

 monuments of denudation are before you. In the distance about half 

 a mile is the " Pinnacle " a large isolated piece of high rock, standing 

 midway in the upper part of the mill pond. But at your side on the 

 south side of the road along which you are travelling, your attention 

 is arrested by a great hole at the base of the rocks. This is the 

 entrance to a cave, which on examination proves to be of more than 

 passing interest. In a line almost sovitheast of this and only a short 

 distance away, but on the top of the bluff", you reach a pothole which 

 rivals some that for years have been a great source of attraction to 

 tourists stopping at Lucerne, Switzerland. Woodcuts of these are 

 scattered in every direction, and no one can say that he has made a 

 proper visit to Lucerne unless he has visited the " Glacier Garden " 

 and observed the seven potholes, that are silent monuments of glacial 

 phenomena long since ended — Yet here at Rockwood we can get a 

 series of potholes larger in some respects and more unique than those 

 at which so many thousands gaze in wonder each passing year. The 

 formation and origin of these we will consider subsequently. 



2. — ^Description of the Caves. 



The entrance to the main cave is 15 feet high and obstructed by 

 great masses of rock, which have fallen from the roof. From the top 

 of the cave to the summit of the overhanging rock is 40 feet of 

 solid dolomitic limestone. Proceeding into the cavern you observe 

 that the roof is very irregular, sinking at times to 5 feet, then rising 

 to 7 and sinking again. At the mouth it is 29 feet wide and narrows 

 to a width of 16|^ at a distance of 36 feet from the entrance. Here 

 3 



