VOLCANOES AND 



spread. If we had a pyramid of the same materials 

 five miles high, the tendency to spread would not be so 

 great, but still it would be there. Consequently, wher- 

 ever there are high mountains there is a tendency of 

 the earth strata beneath them to spread, perhaps slowly, 

 but inevitably; and if there is any weakness in the 

 structure of the rocks near the base of the mountain, 

 then these will give way with a crash. A great " fault " 

 will be produced, and with it an earthquake. 



People living on the earth will only see the results of 

 the earthquake on the ground just immediately below 

 their feet; and there these results are often very destruc- 

 tive to life and property ; yet if they were all that 

 happened, we should expect them to be covered up in 

 time, and the " geological record " of an earthquake 

 would not be a very important or even discernible thing 

 a million years after it had happened. But are these 

 things, which the eye of man can perceive, the only 

 things that are happening during an earthquake? Is 

 nothing happening underneath the earth which will 

 leave its mark thousands of years after man has left 

 the spot where the earthquake took place ? May it not 

 be that the earthquake is the outcome of some mighty 

 force deep down in the earth ; and may not this force 

 cause both the earthquake and the geological "fault" 

 which remains as the witness of its occurrence ? If this 

 be the case then the earthquake may be of enormous 

 importance in geology. 



We regard an earthquake, as we see it, as a destruc- 

 tive force. That is because it destroys the works of 



i So 



