Science, Geology and Physics 



in its geology. The ground has been the subject of a multitude 1901 

 of scientific treatises. . . . In no one place however has 

 the general purport of all these various studies been brought 

 together so that the intelligent traveler or student can acquire 

 them in convenient form. It is for this reason that Dr. Grabau's 

 work in bringing together in concise form the essence of these 

 investigations, tempered and proved by his own review of them 

 in the field, will not fail to prove serviceable to a large element 

 of the public. 



It is hardly necessary to say that the various theories have 

 been most fairly and impartially reviewed. Mention should 

 perhaps be made of the helpful bibliography of Niagara and the 

 Great Lakes which has been appended to the work. 



This same valuable article forms the appendix to the Eighteenth Annual 

 Report of the Commissioners of the State Reservation at Niagara, and con- 

 tains also a Partial Bibliography of the Geology of Niagara and the 

 Great Lakes. 



Grant, G. C. Niagara Falls as an index of time. (Hamilton Scien- 1901 

 rific Assn. jour, and proc. 1901. 17:78-83.) Grant 



A statement of the difficulties of determining time by geologic strata, 

 and especially by the receding of Niagara Falls; with some reference to 

 time as determined by paleontological methods. 



HlTCHCOCK, C. H. The story of Niagara. (Ann. rep'ts of the 1901 

 com'rs of the state reserv. at Niagara. Albany: 1901. 17:75-107.) Hitchcock 



Reprinted from the American Antiquarian, 1901. "The story of the 

 gorge, then, shows much complication. It will be our task to state what the 

 principal events in the history of this region have been, so as to be able to 

 judge of the value of computations based upon the work performed." 

 Among the tcpics discussed are the early geological history, the advent of 

 the ice age, the reality of St. David's channel, the erosion of the lower 

 gorge, the history of the Great Lakes, the upper section of the gorge, the 

 recession of the cataract, estimates of the age in years, these constituting 

 the principal events in the Niagara district. 



There is, so far as is known, no better locality than the region 

 of the Niagara gorge to afford an insight into the length of 

 time that has elapsed since the disappearance of the ice-sheet 



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