vI MOUNTAINS . 247 
always been found that the seat of disturb- 
ance must have been within 30 geographical 
miles of the surface. . 
Yet, though we cannot connect volcanic 
action with the central heat of the earth, 
but must regard it as a minor and _ local 
manifestation of force, volcanoes still remain 
among the grandest, most awful, and at the 
- game time most magnificent spectacles which. 
the earth can afford. 
