CHAPTEK XXVIII. 



SOME EFFECTS OF THE GLACIAL PEKIOD. 



There is a wonderfully interesting effect 

 produced by the action of water during the 

 subsidence of a glacier at Lucerne, Switzer- 

 land. Some years ago there was discovered 

 under a pile of glacial drift at the edge of the 

 town of Lucerne a number of deep holes worn 

 in a great ledge of rocks that crop out at that 

 point. One of these pot-holes having been dis- 

 covered, excavations were continued until a 

 large number of them were unearthed of vari- 

 ous shapes and sizes. I had the pleasure of in- 

 specting some of them in the year 1881. They 

 are situated within an in closure called the 

 Garden of the Glaciers. Some of these holes 

 are twenty to thirty feet in diameter, and the 

 same depth. There are others that are smaller 

 in size, but all of them possess the same gen- 

 eral characteristics. 



In the bottom of each one was found a 

 bowlder, and in one or two cases two of them. 

 The action of the water had given these bowl- 

 ders a gyratory motion, which gradually wore 



