RENDU AND HIS EDITORS, 451 



candidate for the Copley medal/ which the Council of the Royal Soci- 

 ety did not grant. He was angry at the time ; but it pleases me to re- 

 member that subsequently in the Athenseum Club he renewed acquaint- 

 ance with me, and gave me the benefit of his most agreeable and in- 

 structive conversation about glaciers. 



The letter from Dr. Playfair can also be placed in a moment in its 

 proper relation to other facts. Afoot-note at page 195 of the first 

 edition of "Heat as a Mode of Motion" runs thus: "Since the above 

 was written, the * Glaciers of the Alps ' has been published, and soon 

 after its appearance a ' Reply ' to those portions of the work which 

 referred to Rendu was extensively circulated by Principal Forbes. 

 For more than two years I have abstained from answering my dis- 

 tinguished censor, not from inability to do so, but because I thought, 

 and think, that within the limits of the case it is better to submit to 

 misconception than to make science the arena of a purely personal 

 controversy." N'ot for two years, but for ten years did I permit, for 

 peace' sake, this misconception to continue ; it refers to allegations as 

 to omissions made against me by Principal Forbes, and disposed of at 

 p. 498 et seq.^ vol. xxii. of the ContempQrary Review. 



It will be seen at the place here referred to, that the strongest 

 argument of Principal Forbes relates to a statement regarding cre- 

 vasses made by Rendu ; and Mr. George Forbes now contends for the 

 correctness of his father's views. I can assure him, in all good temper 

 and good faith, that he is hopelessly wrong ; that his father entirely 

 misapprehended Rendu ; and that the argument founded on this mis- 

 apprehension, though apparently so incontrovertible, and so damaging 

 to me, is in reality not worth the paper on which it stands. During 

 the lifetime of Principal Forbes I never once disturbed him in the 

 enjoyment of his delusive triumph, and my life also would have passed 

 without any attempt at refutation had not his biographers flaunted 

 the argument again in my face, and compelled me to reduce it to the 

 condition in which it appears in my last article. Had I, as alleged, 

 been disposed to wound Principal Forbes, I should not have acted thus. 

 I had stated in the " Glaciers of the Alps," and in this Review, 

 that some very important measurements made by Agassiz in 1841 

 and 1842, by which the differential motion of a glacier was demon- 

 strated, had been ignored in all the writings of Principal Forbes. 

 Though so much occupied with the subject, I was in absolute igno- 

 rance of the existence of these measures myself until my attention was 

 drawn to them by Sir Charles Wheatstone, immediately before the 

 publication of the " Glaciers of the Alps." Prof. George Forbes 

 now charges me with forgetfulness of the fact that it was his father 

 who suggested to M. Agassiz the measurements he made; meaning 

 thereby, I suppose, to intimate that his father was not called upon to 

 recognize measurements which were the result of his own instruction. 

 ^ On this subject, see Prof. Huxley's masterly letter in ITaticre, May 22, 1873. 



