,9o6.] SEE— THE CAUSE OF EARTHQUAKES. 405 



relief whatever is afiforded, and the result is a most terrible earth- 

 quake. 



11. The mountains are formed by the injection of steam- 

 saturated lava under the coast, which breaks the overlying surface 

 rocks and gives rise to a ridge parallel to the sea. This is why all 

 mountains are formed parallel to the seashores. 



12. By continually injecting the land with lava from under the 

 bed of the sea the coast is raised and the mountains upheaved, and 

 some of them usually break out into volcanoes ; while at the same 

 time the support of the sea bottom is undermined by the thinning 

 out of the fluid substratum, and at intervals the bottom sinks down 

 to restore stability. 



13. The sinking of the sea bottom in this natural process of 

 earthquake injection of the land is the cause of that class of sea 

 waves found to follow violent earthquakes, in which the water first 

 withdraws from the shore and then returns as a huge wave. Those 

 waves noticed to rise suddenly without previous recession of the 

 water usually are due to submarine upheavals and eruptions in the 

 bed of the sea. 



14. Islands are built up by injection from the sea, and hence 

 have their mountains as veritable backbones, because the injection 

 is symmetrical from both sides. In many cases the sea bottom is 

 thus, undermined and finally sinks down, making a hole beside the 

 island, or a trench. The fact that all islands are not accompanied 

 by such sinks is no argument against the theory, because the subsi- 

 dence has not always taken place ; it is the occurrence of even a con- 

 siderable number of such sinks beside islands which proves the 

 validity of the theory. Such intimate associations between elevation 

 and depression could not be the result of chance. 



15. In the repair of ocean cables broken by earthquakes, subsi- 

 dence of the sea bottom is frequently found to follow these dis- 

 turbances. This is a direct observation of the above effects in certain 

 cases which are established by actual measurement, the subsidences 

 frequently amounting to hundreds of fathoms. 



16. The sea bottom does not subside without the lava under the 

 crust being forced out into some other place, as into islands, sub- 

 marine ridges, or shores ; none of this movement is due to the 



