128 A CENTURY OF SCIENCE 



with the views of Edward Hitchcock (1841) 17 that major 

 valleys and mountain passes are structural in origin and 

 that even subordinate folds and faults may determine 

 minor features. "Is not this a beautiful example of 

 prospective benevolence on the part of the Deity, thus, 

 by means of a violent fracture of primary moun- 

 tains, to provide for easy intercommunication through 

 alpine regions, countless ages afterwards ! ' ' The extent 

 of the wandering from the guidance of DeSaussure and 

 Playfair after'the lapse of 50 years is shown by students 

 of Switzerland. Alpine valleys to Murchison (1851) 

 were bays of an ancient sea; Schlaginweit (1852) found 

 regional and local complicated crustal movements a satis- 

 factory cause, and Forbes (1863) saw only glaciers. 



Valleys Formed by Rivers. 



One strong voice before 1860 appears to have called 

 Americans back to truths expounded by Desmarest and 

 Button. Dana in 1850 18 amply demonstrated that val- 

 leys on the Pacific Islands owe neither their origin, 

 position or form to the sea or to structural factors. 

 They are the work of existing streams which have eaten 

 their way headwards. Even the valleys of Australia 

 cited by Darwin as type examples of ocean work are 

 shown to be products of normal stream work. Dana 

 went further and gave a permanent place to the Hut- 

 tonian idea that many bays, inlets, and fiords are but the 

 drowned mouths of stream-made valleys. In the same 

 volume in which these conclusions appeared, Hubbard 

 (1850) 19 announced that in New Hampshire the "deepest 

 valleys are but valleys of erosion." The theory that 

 valleys are excavated by streams which occupy them 

 was all but universally accepted after F. V. Hayden's 

 description 20 of Rocky Mountain gorges (1862) and New- 

 berry's interpretation of the canyons of Arizona (1862) ; 

 but the scientific world was poorly prepared for New- 

 berry's statement: 21 



"Like the great canons of the Colorado, the broad valleys 

 bounded by high and perpendicular walls belong to a vast system 

 of erosion, and are wholly due to the action of water. . . . The 

 first and most plausible explanation of the striking surface fea- 

 tures of this region will be to refer them to that embodiment of 



