454 THE POPULAR SCIENCE MONTHLY. 



scientific man, to turn away by soft answers the wrath excited against 

 me. I failed to do so. The tone of depreciation indulged in was 

 typified by the remark of Dr. Whewell abov^e quoted, and threats of 

 punishment were everywhere rumored. I refer to these almost for- 

 gotten occurrences, which need never have been revived, to show how 

 natural it would have been for me to assume in the " Glaciers of the 

 Alps " a more decidedly controversial tone than that actually assumed 

 in it. 



Many of the claims then made for Principal Forbes were perfectly 

 inconsistent with the facts known to me. Sir Charles Wheatstone 

 had pointed out those measurements to which Agassiz refers as having 

 been begun under Prof. Forbes's eyes, and which were more than 

 ignored. I had also read Rendu's Essay, and found there matters 

 absolutely unknown to the supporters of Principal Forbes, and directly 

 at variance with statements current in high quarters. I also noticed, 

 or thought I noticed, a tendency, glanced at in my former article, to 

 regard the self-same data as important or unimportant according as 

 they were employed by Forbes or Rendu. 



Let me illustrate my meaning here. One of the strongest passages 

 cited by Principal Forbes to show that he had recognized the merits 

 of Rendu, which I never denied, but expressly admitted, is this 

 ("Travels," page 382) : *'The idea of comparing a glacier to a river 

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

 parison or analogy as an original one. Something very like a concep- 

 tion 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. Renduj whose mechanical views are in many respects 

 more precise than those of his predecessors or contemporaries, speaks 

 of * glaciers d'ficbulement ' as distinct from ' glaciers Reservoirs,' and 

 in the quotation at the head of this chapter he contemplates the possi- 

 Hlity of the mutual pressures of the parts overcoming the rigidity. 

 He is the only writer of the glacier school who has insisted on the 

 plasticity of the ice, shown by moulding itself to the endlessly varying 

 form and section of its bed ; and he is also ojDposed to his leading 

 contemporaries in his conjecture that the centre of the ice-stream 

 would be found to move fastest. But," and here comes one of those 

 qualifying phrases to which I have already referred,^ — "M. Rendu has 

 the candor not to treat his ingenious speculations as leading to any 

 certain result, not being founded on experiments worthy of confidence." 



I will ask permission to go one step farther. At the British Asso- 

 ciation Meeting at York, that able mathematician and high-minded 

 gentleman, Mr. W. Hopkins, got into a sharj) discussion with Prof. 

 Forbes regarding the viscous theory, and he, subsequently, wrote upon 

 the subject in the FMlosopliical Magazine. In the same journal 

 Forbes published a reply ; one of the strongest points of which, if 



* Contemporary Review, vol. xxii., p. 507. 



