542 THE LIFE OF JAMES D. FORBES. [AITEND. 



periments before be saw the Bishop's work ; l and even if he had seen it, the 

 possession of a conjecture which its own author distrusted, cannot, in the 

 slightest degree, affect either the originality or the merit of his discovery.' 



This extract alone appears to afford ample evidence, that 

 Rendu's belief in the more rapid central motion of the glacier- 

 stream was known ' in this country ' by other persons as well 

 as by myself; and also that he was allowed to have applied it to 

 illustrate the analogy which he had conceived to the motion of a 

 fluid body. 



Moreover, in the North British Review for August 1859, from 

 which Professor Tyndall quotes at page 306 of his Glaciers of 

 the Alps, the following passage immediately precedes that which 

 he has selected : 



'. . . While we give all honour to the Bishop for an idea which possesses so 

 much ingenuity and truth, we must admit that it was a mere conjecture, 

 hardly admitted as of any value by the author himself, and that it might never 

 have been heard of had not Professor Forbes, with great candour, given it 

 currency at the same time that he published his own theory, of which it was 

 but the germ.' 



Those who can recollect the silent disregard with which the 

 pamphlet of Rendu was at first received the ridicule, even, with 

 which my attempts to base on rigorous demonstration the quasi- 

 fluid behaviour of the glacier-stream were assailed, and the deaf 

 ear turned for so many years to all the arguments by which I 

 could enforce the analogy which to Professor Tyndall himself 

 appears now so plain, may afford to smile at the notion, that 

 the evidence brought forward in the TJieorie of the Bishop of 

 Anility could have silenced ' the sneers of a presumptuous cri- 

 ticism, ' to which, in the language of the same reviewer, my 

 arguments were exposed, or that they would have excited atten- 

 tion now, save by the reflected light which a long and persevering 

 discussion of the subject has thrown upon it. 



To conclude : In the whole of this matter I am conscious of 

 having acted an honourable and a loyal part towards Monsei- 

 gneur Rendu. I unhesitatingly quoted those passages of his 

 Essay in which his statements approached nearest to my own 

 doctrine the ductility of a glacier as a whole, with which I 

 felt my credit and originality most closely bound up. 2 So fully 



1 [I had indeed seen it, but little more. See page 9 of this Reply (I860).] 



2 It will have been noticed that my Extracts from Rendu's writings bore ex- 

 clusively upon such of his views as have been upon the whole confirmed, and 

 which may be regarded as his happiest prognostics. Nowhere have I allowed 

 myself to detract from his merit by quoting, as a set-off, the few indifferent ob- 

 servations or inaccurate deductions or hazarded hypotheses which his work 

 contains, and of which it cannot be supposed that I was ignorant. If I have 

 been compelled to allude to one or two of these in the present Reply, it is be- 

 cause they have been extorted by the partial citations and unwarrantable claims 

 which have been unwisely set up on his behalf. 



