450 THE POPULAR SCIENCE MONTHLY, 



the same numerical result. These assertions were uttered with a con- 

 fidence not surpassed by any thing contained in the volume just pub- 

 lished by Mr. Macmillan. The sufficient reply to all this now is, that, 

 since those days of strife, Dr. Mayer has received the highest rewards 

 which the greatest scientific academies and societies in Europe could 

 confer upon him ; and that he now stands above detraction and debate, 

 immovably fixed beside his illustrious experimental brother. Joule : a 

 figure memorable to all time in the annals of science. 



The gentle knight who in those days, with such conspicuous disaster 

 to himself, took the field against me, is also my chief opponent now. 

 He is the principal figure among the authors to whom I have referred, 

 and I allude to these facts in order to bring him and his work into the 

 causal series of contemporary phenomena, and to show cause for the 

 warning that obstinacy of assertion on his part furnishes a by no 

 means sufficient assurance that his assertions are objectively correct. 

 Indeed, where we find these assertions associated with more than the 

 usual want of sweetness and luminosity, the presumption arises that 

 the judgment which proved entirely fallacious on a former occasion 

 may at present, to say the least of it, be unsound. 



The volume which calls forth these remarks is entitled " Theory 

 of the Glaciers of Savoy," by M. le Chanoine Rendu ; and the middle 

 of the book is, I am happy to say, occupied by a translation of this re- 

 markable essay — in itself a perfectly honorable and praiseworthy work. 

 The volume opens with an introduction by Prof. George Forbes, son 

 of the late Principal Forbes, which, measured by former discussions 

 on this subject, is by no means immoderate in tone. Had this tone, 

 indeed, been preserved throughout the discussion, these remarks of 

 mine would never have been written. It is not in my nature to refuse 

 sympathy to a son battling, as he imngines, for the honor of his father. 

 But Prof. George Forbes has deliberately taken upon himself the re- 

 sponsibility of writings, samples of which shall be given further on, 

 not with the view of maintaining his father's honor, but with the view 

 of gratuitously sullying the honor of others. This, filial allegiance 

 neither demands nor can excuse. 



He prints some letters in his Introduction animadverting more or 

 less upon me and my friends ; but written at a time when the writers 

 were very inperfectly acquainted with the subject on which they wrote. 

 Dr. Whewell was from the first a warm supporter of Principal Forbes, 

 and an equally warm opponent of Mr. William Hopkins; and, when 

 my small labors on the glaciers came to be discussed, the preexisting 

 difference between these two distinguished men became intensified, in 

 a high degree. It was Dr. Whewell who, in discussion with Mr. Hop- 

 kins, summed up my doings with the remark that I had simply taken 

 Auguste Balmat to the summit of Mont Blanc and caused him to be 

 frost-bitten.^ It was he who in 1859 proposed Principal Forbes as a 

 * CoTdemporary Review, vol. xxii., p. 485. 



