Proceedings. 61 



earthquakes probably are the most terrifying in their effects, 

 especially when the couvulsions are violent. Earthquakes 

 are of more frequent occurrence than might at first be sup- 

 posed. In Palermo fifty-seven earthquakes occurred in forty 

 years, each one thoroughly noticeable by a casual observer : 

 that is, nearly three convulsions in every two years. In the 

 town of Copiapo, in the northern province of Chili, earth- 

 quakes are of almost daily occurrence, but only occasionally 

 of a force sufiScient to create much damage. The inhabitants 

 accustomed to these visitations, at the first notice of them, if 

 in the day-time, rush out of their houses, and thus, when the 

 shocks ai'e of sufficient force to throw down buildings, save 

 their lives. When the shock comes in the dead of night, the 

 danger to the people is of course so much greater. 



If we could obtain accurate accounts from all parts of the 

 world, it is not at all improbable it would appear that some 

 portions of the earth's surface are in movement every day, 

 so that the surface as a whole is never entirely at rest. Some 

 districts are, however, much more subject to earthquakes than 

 others ; but the phenomenon is found in all countries — among 

 mountains, on the low lands, and in plains at high-level. 

 Sometimes when the plain is violently disturbed, the neigh- 

 bouring mountains feel no shock, or again, when the moun- 

 tains are convulsed, the plain is left undisturbed ; at other 

 times the whole district, whatever the character of the country, 

 is subject to the disturbance. 



It does not appear that the geological structure of the 

 country has much, if any, influence on the occurrence of 

 earthquakes. They occur among the formations of the 

 primitive rocks, and in the districts of post-tertiary deposits ; 

 in the low-lying plains of the Scheldt and the Mississippi ; 

 and in the tertiary deposits of our own country, as may be 

 remembered iu the instance of the earthquake in Essex in the 

 year 1884, when 31 places of worship and 1300 buildings 

 were damaged. Slight shocks of earthquakes have not un- 

 frequently been felt of late years, and perhaps in former days, 

 in Wales and in Devonshire. The neighbourhood of Crieff, 

 in Scotland, is very liable to earth-disturbances, but they are 



