VOLCANOES AND 



Japan, near the Aleutian Island, west of South America, 

 near Guam, between Samoa and New Zealand, give rise 

 to enormous leakage of the sea bottom, and consequently 

 many world-shaking earthquakes ? A comparatively feeble 

 pressure of water, such as hydraulic engineers use in 

 mining, rapidly cuts away hills and washes out all their 

 gold; in the same way the waters of Niagara, falling 

 through only 160 feet, slowly wear away the solid rock 

 over which they pour. What, then, may be expected of a 

 constant water pressure which will throw a jet five miles 

 high ? Such is the pressure all over the bed of the 

 Tuscarora Deep, and it continues from year to year, 

 century to century. It is this pressure which forces the 

 water so rapidly into the earth, and gives rise to all the 

 great earthquakes and sea-waves with which Japan is 

 afflicted. No stone on earth, however thick its layers, 

 could withstand such a pressure ; nay, under it the water 

 would go through the hardest metals, and sink down 

 deeper and deeper into the bowels of the earth. Thus 

 subterranean steam would arise beneath the crust and 

 accumulate till relief was afforded by a shaking of the 

 earth. 



Thus we see how immensely important the same causes 

 that give rise to earthquakes may be in moulding the 

 outlines and contours of the rocks and the " everlasting 

 hills." In the present state of geological knowledge 

 we cannot say that these steam explosions are the sole 

 causes of mountain building, but it is evident that they 

 must play a great part in them. The action of the 

 submarine explosions may be compared to a man digging 



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