360 The Philosophy of Earthquakes. 



of unsupported strata, which may take place in consequence of 

 an earthquake, or may occur without its aid. 



If we look at the Seismographic (" Quake-descriptive ") 

 map of the world, drawn by Messrs. Kobert and William Mal- 

 let, and published in the British Association Catalogue, we see 

 some connection between the principal lines of earthquake 

 action — and the great mountain chains. We likewise see that 

 our islands — although not far from Iceland, in which such action 

 is violent, or from Southern Italy, in which it produces very 

 serious effects — lie in a region of comparative calm, which is not 

 likely to be exchanged for one of earthquake storm, except by 

 the very slow operation of causes, which would alter the phy- 

 sical geography of our portion of the globe. 



Hereafter, when men know better how to guard against the 

 perils of earthquakes, highly industrious and civilized commu- 

 nities may live in regions subject to severe shocks ; but the 

 chief seats of progressive races have hitherto been in places 

 tolerably secure. But, notwithstanding their dangerous cha- 

 racter, when shocks are frequent, people get so used to them, 

 that Humboldt tells us of districts in South America " in which 

 the inhabitants take no more notice of the number of earth- 

 quakes than we in Europe of that of showers of rain," and 

 where, he adds, Bonpland and- himself were compelled to dis- 

 . mount on account of the restiveness of then mules, " because 

 the earth shook in a forest for fifteen to eighteen minutes 

 without interruption." Of such localities Sir C. Lyell well ob- 

 serves, that " where earthquakes are frequent, there never can 

 Vbe perfect security of property under the best government ; 

 industry cannot be assured of reaping the reward of its labour, 

 and the most daring acts of outrage may be perpetrated with 

 impunity when the arm of the law is paralyzed by general con- 

 sternation. It is hardly necessary to add that the progress of 

 civilization and national wealth must be retarded by convulsions, 

 which level cities to the ground, destroy harbours, make roads 

 impassable, and cause the most cultivated valley plains to be 

 covered with lakes, or the ruins of adjoining hills." 



The bands of seismic influence " very generally follow the 

 lines of elevation which mark and divide the great oceanic or 

 terr-oceanic basins (saucers) of the earth's surface. And, in so 

 far as these arc frequently the lines of mountain chains, and 

 these latter those of volcanic vents, so the seismic bands aro 

 found to follow thern likewise." Thus says the British Associa- 

 tion Catalogue, and it. adds, that "the surfaces of minimum, or 

 of no known disturbance, are the central areas of great oceanic 

 or terr-oceanic basins, or saucers, and the greater islands exist- 

 ing in shallow seas." The Ganges and Mississippi river liasins, 

 as explained, do not conflict with this last proposition, as when 



