Trans. N. V. Ac. Sci. 82 Jan. 9, 



Hudson and Mohawk, and sweep the valley of the Mississippi to the 

 basin of the Great Lakes. Rocks would be torn from their beds, and 

 with all loose material, boulders, gravel, sand and clay, would be swept 

 to and fro with overwhelming violence, and finally be spread far out 

 over the bottom of the adjacent ocean. All this broad littoral zone, 

 now crowded with life, and the scene of greater vital activity than any 

 other equal area above or below the ocean level, would become at once 

 a howling wilderness, where nature's forces waged perpetual war, and 

 lile would be impossible. 



So on all other shores, the physical and vital changes would be im- 

 measurable. Erosion would be carried on with such energy that soon 

 all continents would be worn away, all mountains be transported into 

 the sea. All coral reefs, all sea-weeds, and indeed niue-tenths of all 

 the lite on the globe, would, however, be swept out of existence before 

 that time. Half the land of the globe would be submerged and deso- 

 lated, and, with the destruction of the marine and the restriction to 

 narrow limits of terrestrial vegetation, the pabulum of animal life would 

 be so much reduced that the globe would be practically depopulated. 



It may also be said that if, as we suppose, the precipitation of ocean 

 waters took place before the corrugations ot the ear h's surface had as- 

 sumed any considerable magnitude, and it was rearlyor quite covered 

 with water, tidal waves 500 feet or more in he ght, sweeping over the 

 globe in rapid succession, would have worn away the emerging 

 land as fast as it appeared, would have prevented the formation of 

 continents and have precluded the existence of land animals or plants. 



From these facts, it will be seen that if such tides had been at any 

 time in existence on the earth's surface, traces of their action would be 

 universal and indisputable. 



Having studied with some care the geological record in places where 

 it is as nearly complete as anywhere, 1 must say that 1 not only fail 

 to find any proof of the existence of these stupendous tides pictured 

 to the imagination by Prof. Ball, but, on the contrary, the whole of that 

 record, from the Archsean to the Tertiary, offers abundant and conclu- 

 sive evidence against such a theory. 



As to what took place before the deposition of the Laurentian strata, 

 we can have no knowledge, because they are the oldest known rocks 

 yet the era of their deposition can hardly have been less than twenty or 

 thirty millions of years ago. Though much changed from their original 

 condition as aqueous sediments, we are yet able to recognize in them the 

 prototypes of the sandstones, shales and limestones of later formations, 

 and we may fairly conclude that they were deposited under like condi- 

 tions. In the gneiss and granite of the Laurentian we have representa- 

 tives of the coarser sediments formed along shores ; the slates are the 



