414 



Popular Ficicncc Monihhi 



The Upper BoiJder 

 Is of Massachusetts 

 Granite. It Is Rest- 

 ing on a Rock of 

 Gneiss, and Both 

 are Perched on a 

 Granite Ledge of 

 Different Texture 

 From That of the 

 UpperOranite Rock 



At Left Below, A 

 Rock Transported 

 and Deposited by 

 Huge Glaciers from 

 the Sierra Nevada. 

 This Rock will Out- 

 last Its Base Many 

 Thousand Years 



Below, An Erratic 

 Rock Fragment 

 Resting on a Big 

 Base, Brought to 

 Its Present Posi- 

 tion by an Agency 

 Powerful Enough 

 to Transport It 

 Over Irregularities 

 in Land Surface 



