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out 

 after- 



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Ch. XXXIII.] FLEXIBILITY OF THE EAETH'S CEUST. 



227 



to discover some cause which, is capable of bringing abont 

 such a concentration of heat as may melt, one after the 

 other, certain portions of the solid crust so as to form seas 

 lakes, or oceans of subterranean lava. This being granted 



more 



The general 



the greater part of the crust at any given time will contain 

 at various depths sheets of such lava slowly partino* with 



less viscouSj and 

 otliers beginning to consolidate or crystallise. 



state, therefore, of the exterior of the planet wonld be that of 

 a mass once heated, and which has been gradually coolino- ; 

 but in certain spots, namely the regions of active volcanos, 

 regions very limited and exceptional as regards the whole 

 surface, the heat will be on the increase, and will occasion- 

 ally manifest its intensity in the operations of the volcano 



and the earthquake. 



And 



volcanos 



great areas of active 



mile 



of lava in a constant state of fusion, cannot be doubted from 

 what we have already stated (pp. 90 and 202) . All the observed 



enomena 



been inferred are reconcilable with the occurrence at certain 

 depths of such masses of lava in the earth's crust as we 

 have admitted to be probable, and which, even if they 



volume 



may 



hold a very subordinate place in the solid shell of the planet. 

 The connection of earthquakes with a flexible crust overlyino- 



melted 



of the earth's crust.—Tlie inhabitant 

 mostly fishermen, are said to make 



om 



com 



feeble when the sky is serene, but increasing in turbulence 

 durmg tempestuous weather, so that in winter the island 



after 



seems to sJiake from its foundations. Mr. P. Scrope, 

 calling attention to these and other analogous facts' 

 first started the idea (as long ago as the year 1825) that the 

 dnnmished pressure of the atmosphere, the concomitant of 

 stormy weather, may modify the intensity of the volcanic 

 action He suggests that where liquid lava communicates 



Stromboli, it may 



Q2 



■- --. 



M 



