MOUNTAIN FORMATION 



when M. Junius Silanus and L. Balbus were consuls, on 

 the 8th of the Ides of July. 



" Opposite to us, and near to Italy, among the JEolian 

 Isles, an island emerged from the sea ; and likewise one 

 near Crete, 2500 paces in extent, and with warm springs 

 in it; another made its appearance in the third year 

 of the 163rd Olympiad, in the Tuscan Gulf, burning 

 with a violent explosion. There is a tradition, too, that 

 a great number of fishes were floating about the spot, 

 and that those who employed them for food immediately 

 expired. It is said that the Pithecusan Isles rose up in 

 the same way in the Bay of Campania, and that shortly 

 afterwards the mountain Epopos, from which flame had 

 suddenly burst forth, was reduced to the level of the 

 neighbouring plain. In the same island it is said that 

 a town was sunk in the sea; that, in consequence of 

 another shock, a lake burst out, and that, by a third, 

 Prochytas was formed into an island, the neighbouring 

 mountains being rolled away from it." 



There are, no doubt, other causes which warp and 

 bend strata. We have compared the earth to the core 

 of a tightly wound golf ball always in a state of strain. 

 The strain at great depths below the surface might 

 amount to several tons to the square inch, and it can 

 easily be understood that breaks might occur in con- 

 sequence, especially if some slight additional shock set 

 the rocks into vibration. In the deep copper mines of 

 the northern peninsula of Michigan the behaviour of 

 the whole earth, with respect to earthquakes and stresses 

 due to other causes, is well illustrated on a small scale. 

 N 193 



