462 Scientific Proceedings, Royal Dublin Society. 



h vdrograpliy of a countiy is equivalent to the study of what may be 

 called the keys of the internal telluric activity." He adds (p. 15) : 

 " The tempests and the extraordinary storms, the centres of baro- 

 metric depressions which have sojourned more or less in a river- 

 basin, will be found to be phenomena proper to each particular 

 basin, and capable of influencing its endogenous activity." 



Referring to the importance to be attached to the examination 

 of precipices and cliffs as connected with Assuring, and thus with 

 former earthquake-action, he says (p. 15) : " Taramelli with good 

 reasons thinks that in a post-glacial epoch, but pre-historical, the 

 surface of Italy was subjected to an extraordinary endogenous 

 activity and to seismical convulsions far greater than those known 

 or recorded in historical times, and that at that period were pro- 

 duced the great fracturings, having giving rise to cliffs, and the 

 consequent incumbering of the valleys of fracture with detritus, 

 and to alterations in the regimen of the hydrographical basins." 



With these phenomena he connects that of the formation of 

 travertine, and considers that both together point to an immense 

 development of endogenous activity during the post-glacial period, 

 which also was that of the littoral volcanoes of Italy ; so that the 

 littoral vulcanism and its secondary and inland manifestations 

 correspond to a same geological era. 



