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THE POPULAR SCIENCE MONTHLY. 



to 4,000 feet hi<rh, extending 60 miles, but of not more than 18 inches 

 in average width. 



During the Calabrian earthquake of 1783 the surface of the ground 

 opened and closed in immense fissures, by means of which new lakes 

 were formed and others drained or were dried up. 



At Jerocarne the earth is described, by Sir Charles Lyell, as lacer- 

 ated in an extraordinary manner. " Fissures ran in every direction, 

 like cracks in a broken pane of glass." 



Fig. 2. 





FisauEES neab Jeeocabne, in Calabbia. 



In another instance, several dwellings were engulfed in a fissure, 

 and were found to be jammed with their contents into a compact mass. 

 Chasms of immense length and depth were formed. Some were cres- 

 cent-shaped, and a mile in length. 



The plains of Calabria were covered in many places with circular 

 hollows from one foot to three or four feet in diameter. Some of these 

 were filled with water, others with dry sand. 



Fig. 4 is a section of one of these circular holes, which appears to 

 be funnel-shaped. 



But changes in the earth's crust occur during earthquakes, on a 

 still grander scale. Evidences of local disturbance, however disastrous 

 it may have been, are often effaced if not forgotten in a few centuries 

 frequently in a few years. But the slow upheaval of mountain-chains 

 and the dislocation of strata through profound depths are results which 

 alter at last the physical aspect and contour of the surface of the 

 globe. It would not be proper, however, to say that these changes are 

 caused by earthquakes, but rather that the earthquake vibration is a 

 concomitant of the displacement by which they are produced. 



Humboldt, Lyell, Dana, and other authorities, consider earth 



