EARTHQUAKE IN PERU. 213 



is said that in Chili a year scarcely ever passes without 

 shocks of earthquake being felt ; in certain regions, not 

 even a month. A similar persistence of earthquake 

 disturbance characterizes Peru. Yet, although both 

 districts are shaken in this manner, there seems to be 

 a distinct evidence of alternating disturbance as re- 

 spects the occurrence of great earthquakes. Thus, in 

 1797, took place the terrible earthquake of Riobamba. 

 Then, thirty years later, a series of great earthquakes 

 shook Chili, permanently elevating the whole line of 

 coast to the height of several feet. Now, again, after 

 another interval of about thirty years, the Andes are 

 disturbed by a great earthquake, and this time it is the 

 Peruvian Andes which experience the shock. Between 

 Chili and Peru there is a space upward of five hundred 

 miles long, in which no volcanic action has been ob- 

 served. Singularly enough, this very portion of the 

 Andes, to which one would imagine the Peruvians and 

 Chilians would fly as to a region of safety, is the part 

 most thinly inhabited, insomuch that, as Yon Buch 

 observes, it is in some places entirely deserted. 



Near Quito the trembling of the earth is almost in- 

 cessant, according to M. Boussingault. He considers 

 that the frequency of the movement is due rather to 

 the continual falling in of masses of rock which have 

 been fractured in recent earthquakes, than to the per- 

 sistence of subterranean action. He adds that the 

 height of several mountains in the Andes has diminished 



