i9o6.] SEE-THE CAUSE OF EARTHQUAKES. 397 



" Everything in earthquakes seems to indicate the action of elastic fluids 

 seeking an outlet to diffuse themselves in the atmosphere. Often on the 

 coasts of the Pacific, the action is almost simultaneously communicated from 

 Chili to the Gulf of Guayaquil, a distance of six hundred leagues ; and, what 

 is very remarkable, the shocks appear to be the stronger in proportion as 

 the country is more distant from burning volcanoes. The granitic mountains 

 of Calabria, covered with very recent breccias, the calcareous chain of the 

 Apennines, the country of Pignerol, the coasts of Portugal and Greece, those 

 of Peru and Terra Firma, afford striking proofs of this fact. The globe, it 

 may be said, is agitated with the greater force, in proportion as the surface 

 has a smaller number of channels communicating with the caverns of the 

 interior. At Naples and at Messina, at the foot of Cotopaxi and of Tun- 

 guragua, earthquakes are dreaded only when vapor and flames do not issue 

 from the craters. In the kingdom of Quito, the great catastrophe of Riobamba 

 led several well-informed persons to think that that country would be less 

 frequently disturbed, if the subterranean fire should break the porphyritic 

 dome of Chimborazo; and if that colossal mountain should become a burning 

 volcano. At all times analogous facts have led to the same hypotheses. 

 The Greeks, who like ourselves, attributed the oscillations of the ground to 

 the tension of elastic fluids, cited in favour of their opinion, the total cessa- 

 tion of the shocks at the island of Euboea, by the opening of a crevice in the 

 Lelantine plain." ^ 



§ 58. Viezvs of Charles Darwin. 



In the " Voyage of a Naturalist," Chapter xiv, Darwin says : 



" The forces which slowly and by little starts uplift continents, and 

 those which at successive periods pour forth volcanic matter from open 

 orifices, are identical. For many reasons, I believe that the frequent quak- 

 ings of the earth on this line of coast (Chili) are caused by the rending of 

 the strata, necessarily consequent on the tension of the land when upraised, 

 and their injection by fluidified rock. I believe that the solid axis of a moun- 

 tain differs in its manner of formation from a volcanic hill, only in the 

 molten stone having been repeatedly injected, instead of having been re- 

 peatedly ejected. 



" Moreover, I believe that it is impossible to explain the structure of 

 great mountain-chains, such as that of the Cordillera, where the strata, 

 capping the injected axis of plutonic rock, have been thrown on their edges 

 along several parallel and neighboring lines of elevation, except on this 

 view of the rock of the axis having been repeatedly injected, after intervals 

 sufficiently long to allow the upper parts or wedges to cool and become solid; 

 — for if the strata had been thrown into their present highly inclined, vertical, 

 and even inverted positions, by a single blow, the very bowels of the earth 

 would have gushed out ; and instead of beholding abrupt mountain axes of 

 rock solidified under great pressure, deluges of lava would have flowed out 

 at innumerable points of every line." 



^ " The shocks ceased only when a crevice, which ejected a river of fiery 

 mud, opened in the plain of Lelantum, near Chalcis." — Strabo. 



