Science, Geology and Physics 



agricultural purposes, is shown to be baseless, on account of the rock 1873 

 formation. The author says that the " character of the river bed and not HoIIey 

 the depth of water solves the problem of recession, and that will determine 

 both the proximate and distant future of Niagara, so far as its location 

 is concerned." 



TYNDALL, John. Niagara. (Every Sat, May 31, 1873. 14:- 1873 

 595-601.) T y nda11 



The discourse delivered before the Royal Institution April 4, 1873, 

 quoted from Macmillaris Magazine. 



TYNDALL, John. Niagara. (Lit. liv. age, June 7, 1873. 117: 

 609-619.) 



Quoted from Macmillaris Magazine. 



Tyndall, John. Niagara Falls. (Critic, July, 1873. 81:24-35.) 



The discourse delivered before the Royal Institution, April 4, 1873, 

 and reprinted from Macmillans Magazine. 



TYNDALL, John. Niagara Falls: past and future. (In Williams, 

 J. David, ed. America, illustrated. N. Y.: The Arundel print, n. d. 

 Pp. 81-85.) 



Professor Tyndall's article, "A Philosophical Disquisition " as it is 

 called, presents very briefly and simply some observations on the recession 

 of the Falls and the physics or excavation revealed by the Niagara gorge. 

 The article is accompanied by an interesting " Night View of Niagara in 

 Olden Times." 



TYNDALL, John. Some observations on Niagara. (Pop. sci. mo., 

 June, 1873. 3:210-226.) 



A lecture before the Royal Institution, April 4, 1873. 



1875 



BELT, THOMAS. . . . Niagara: glacial and post-glacial phenomena. 1875 

 (Quarterly jour. sci. Lond.: April, 1875. Pp. 135-156.) Belt 



The author gives arguments in favor of his theory, that " the gorge 

 was cut back from the whirlpool up to at least within three-quarters of a 

 mile from the falls before the glacial period." He thinks that " it may 

 have existed to within a few yards of the falls, for anything that can be 

 seen to the contrary." 



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