280 SEE— THE CAUSE OF EARTHQUAKES. [October 19, 



and volcanoes most numerous on the adjacent shores. Could then 

 anything he more probable than to suppose that both of these great 

 natural phenomena depend simply and wholly upon the explosive 

 power of steam which has developed in the heated rock of the earth's 

 crust? 



The mere statement of the facts seems almost enough to con- 

 vince one of the truth of this theory. But in view of the wide 

 differences of opinion heretofore prevaiUng we shall examine it in 

 detail, and we believe it will be possible to show that no contradiction 

 can be established, and that it probably is the correct explanation 

 of the mysterious forces which have so long baffled investigators 

 and wrought such havoc in numerous places throughout the world. 



It would seem that the obvious fact of the leaky character of 

 the sea bottom, covering three-fourths of the earth, with great in- 

 ternal heat everywhere so close beneath and volcanoes not only 

 abundant on the shores adjacent to the deepest seas, but pouring 

 forth vast quantities of steam when in eruption long ago suggested 

 and apparently ought to have convince'd investigators of the validity 

 of this natural and simple explanation. But it appears to have been 

 generally rejected, owing to several circumstances which did not 

 enable investigators to obtain the proper point of view. On the 

 one hand there were traditional theories of volcanoes and their 

 relations to a supposed liquid or molten globe; and on the other 

 little or no adequate knowledge of the enormous number and great 

 violence of submarine earthquakes, which have recently been shown, 

 mainly through the important researches of Professor Milne, to be 

 the most powerful in the deepest oceans. 



While volcanoes and earthquakes have been associated from the 

 time of Aristotle and Pliny, and we think justly so, and some mutual 

 connection could hardly be denied ; yet even after this relation was 

 especially affirmed by great original investigators like Humboldt 

 and Charles Darwin, it has unfortunately become customary of late 

 years to class earthquakes as volcanic and tectonic or structural. 

 Instead of viewing volcanoes as outlets of pent-up-steam, which 

 blows out if possible the molten rock in which it develops — a clear 

 indication of every great eruption — an effort was made to explain 

 earthquakes as volcanic, with only partial success, whereas both 



