xv.] FORBES' GLACIER DISCOVERIES. 507 



so fruitful in results, and though so obvious, still unat- 

 tempted/ 



These observations on the two competing theories are 

 all, with the exception of a very few words, obviously 

 and necessarily correct ; and they show, better than any 

 words of ours could do, how completely original was 

 Forbes' work, the greater part of it having been per- 

 formed under circumstances the most adverse to the 

 starting of a new and correct hypothesis ; as he was so 

 constantly associated with a partisan of one or other of 

 these incorrect theories. 



We now come to his own statement (Travels, pp. 

 382 384) of his views on the subject : 



'.The idea of comparing a glacier to a river is anything 

 but new, and I would not be supposed to claim that com- 

 parison or analogy as an original one. Something very 

 like the conception of fluid motion seems to have been 

 in the minds of several writers, although I was not aware 

 of it at the time that I made my theory. In particular, 

 M. Rendu, whose mechanical views are in many respects 

 more precise than those of his predecessors or contempo- 

 raries, speaks of " glaciers d'ecoulement " as distinct 

 from " glaciers reservoirs ;" and in the quotation at the 

 '1 of this chapter, 1 he evidently contemplates the pos- 

 'tj of the mutual pressures of the parts overcoming 

 the rigidity. 2 He is the only writer of the glacier school 

 who has insisted upon the plasticity of the ice, shown 

 by moulding itself to the endlessly varying form and 

 section of its bed, and he is also opposed to his leading 

 <>n temporaries in his conjecture that the centre of the 

 im would be found to move fastest. But M. 

 Rendu lias the candour not to treat his ingenious specula- 

 is as leading to any certain result, not being founded 

 on experiments worthy of confidence. "The fact of the 

 motion exists," he says, " the progression of glaciers is 

 demons 4 l>ut the manner of it is r/////v/// //////, 



ante, p. 498. 

 2 ' Sea also p. 1 "7 'f his M'ork fir ftcniip.ii i- MM 1 .m.l 



