THE CKTJST OF THE EARTH. 



Unique. It was sensible, also, at right angles to this direction, 

 from Greenland to Africa, where the cities of Morocco, Fez, and 

 Mequinez were destroyed by it. Its effects were manifested in all 

 parts of Europe at the same moment. 



Ill, These convulsions not only destroy entire cities and over- 

 turn the most solid edifices, but they are attended with important 

 modifications in the level* of the ground. Those of Calabria, in 

 1783, supply remarkable examples of them, and are so much the 

 more worthy of attention, as they were circumstantially described 

 by several eminent men who were witnesses of the phenomenon, 

 such as Vicencia, physician of the King of Naples, Grimaldi, Sir 

 W. Hamilton, and by a commission of the Royal Academy of Naples. 

 The whole extent of the country was convulsed, the beds of the 

 rivers were changed, houses were, some raised above the general 

 level, and others at short distances from them sunk below it ; 

 edifices of the greatest solidity were cracked in their walls, while 

 certain parts of them were raised above others, and their founda- 

 tions in many instances forced above the earth ; crevices were 

 formed in the ground, some of which measured five or six hundred 

 feet in width ; some were straight, some bifurcated ; sometimes a 

 single enormous cleft having a certain direction was intersected at 

 right angles by a number of others, fig. 46 ; others were developed 

 in clefts radiating from a centre, like a broken pane of glass, fig. 47. 

 Some crevices laid open at the moment of a shock, and into which 

 entire buildings had fallen, closed almost immediately again, 

 crushing between their sides all that they had thus engulfed. 

 In some cases the sides of the cleft were separated at the surface, 

 but brought into contact with each other at a certain depth, figs. 

 48-9. In other cases, the parts disrupted merely sunk below the 

 other without ceasing to be in contact, fig. 50. 



Fig. 40. 

 Fig. 48. 



In other cases, the force which burst the superior crust was 

 sufficient, not merely to split it into different clefts, but to pro- 

 duce in it a vast cavity, from the edges of which clefts diverged, 

 fig. 51. 



In some cases a considerable tract of ground was suddenly 

 engulfed, carrying with it the plantations and buildings which 

 88 



