A MIGHTY SEA-WAVE. igi 



action is felt in one way or another, it can scarcely be 

 doubted that the earth's Vulcanian energies are at present 

 more actively at work throughout that region than in any 

 other. There is nothing so remarkable, one may even say 

 so. stupendous, in the history of subterranean disturbance as 

 the alternation of mighty earth-throes by which, at one time, 

 the whole of the Chilian Andes seem disturbed and anon 

 the whole of the Peruvian Andes. In Chili scarcely a year 

 ever passes without earthquakes, and the same may be said 

 of Peru ; but so far as great earthquakes are concerned the 

 activity of the Peruvian region seems to synchronize with the 

 comparative quiescence of the Chilian region, and vice versd. 

 Thus, in 1797, the terrible earthquake occurred which is 

 known as the earthquake of Riobamba, which affected the 

 entire Peruvian earthquake region. Thirty years later a 

 series of tremendous throes shook the whole of Chili, per 

 manently elevating its long line of coast to the height of 

 several feet During the last twelve years the Peruvian region 

 has in turn been disturbed by great earthquakes. It should 

 be added that between Chili and Peru there is a region about 

 five hundred miles in length in which scarcely any volcanic 

 action has been observed. And singularly enough, "this 

 very portion of the Andes, to which one would imagine that 

 the Peruvians and Chilians would fly as to a region of safety, 

 is the part most thinly inhabited; insomuch that, as Von 

 Buch observes, it is in some places entirely deserted." 



One can readily understand that this enormous double 

 region of earthquakes, whose oscillations on either side of 

 the central region of comparative rest may be compared to 

 the swaying of a mighty see-saw on either side of its point 

 of support, should be capable of giving birth to throes pro- 

 pelling sea-waves across the Pacific Ocean. The throe 

 actually experienced at any given place is relatively but an 

 insignificant phenomenon : it is the disturbance of the entire 

 region over which the throe is felt which must be considered 

 in attempting to estimate the energy of the disturbing cause. 

 The region shaken by the earthquake of 1868, for instance, 



