The Natural Hiflory Part IIL 



ordinary courfe, by Tome accidental 

 Glut or Obftru£lion in the Pores or 

 PaiTages thrcugU which it uied to al- 

 cend to the Surface : and being by that 

 means preternaturally alTembled, in 

 greater quantity than ufual, into one 

 place, it caules a great Rarifaftion and 

 Intumefcence of the Water of the 

 Abyfs, putting it into very great Com- 

 motion and Difbrders : and at the fame 

 time making the like Effort upon the 

 Eanh, which is expanded upon the 

 face of the Aby fs, it occafions that Agi- 

 tation and Concuffion of it, which we 

 call an Earthquake. 



That this Ejfort is in fome Earth- 

 quakes fb vehement that it fplits and 

 tears the Earth , making Cracks or 

 Chafmes in it fbme Miles in length, 

 which open at the inftants of the 

 Shocks, and clofe again in the Inter- 

 valls betwixt them : nay^ tis fbmetimes 

 fb extremely violent, that it plainly 

 forces the fuperincumbent Strata i 

 breaks them all throughout, and there- 

 by perfectly urdtrmines and ruins the 

 Foundations of them ; fb that thefe 

 tailipg, the whole TraSf, afToon as ever 

 the Shock is over, ft?2ks down to rights 

 into the underneath, and is fwal- 



lowed 



