448 



FIRST YEAR SCIENCE 



time to wear them away extensively, 

 almost perfect in shape like Mt. Shasta. 



Thus they are 

 Others, like Mt. 



MOUNT LASSEN IN ERUPTION. 



This volcano, after being dormant for centuries, suddenly renewed 

 its activity in 1914. 



Hood, have been deeply eroded, but not sufficiently to ob- 

 literate the conical outline. 



In the region around Mt. Taylor erosion has progressed 

 so far that only the roots of the volcanoes still remain, the 

 cones having been entirely worn away and only the central 

 plug of lava left, forming what is called a volcanic neck. 

 In the Aleutian Islands are numerous volcanoes which are 



