75 2 THE POPULAR SCIENCE MONTHLY. 



when he began his investigations, was acquainted with the labors of Eendu. In 

 his earliest works upon the Alps he refers to those labors in terras of flattering 

 recognition. But, though, as a matter of fact, Eendu's ideas were there to 

 prompt him, it would be too much to say that he needed their inspiration. 

 Had Rendu not preceded him, he might none the less have grasped the idea of 

 viscosity, executing his measurements, and applying his knowledge to maintain 

 it. Be that as it may, the appearance of Prof. Forbes on the Unteraar Glacier 

 in 1841, and on the Mer de Glace in 1842, and his labors then and subse- 

 quently, have given him a name not to be forgotten in the scientific history of 

 glaciers." 



Here, again, I have to declare that, in writing thus, I had no no- 

 tion of "raking \ip " an old controversy. My object was to render 

 my account historically continuous, and there is not a single word to 

 intimate that I took exception to Principal Forbes's treatment of 

 Rendu. Nay, while placing the bishop in the position he merited, I 

 went out of my way to point out that, in all probability, Principal 

 Forbes required no such antecedent. So desirous was I that no un- 

 kind or disparaging word should escape me regarding Principal Forbes, 

 that, had a reasonable objection to the phraseology here used been 

 communicated to me by his friends, I should have altered the whole 

 edition of the work sooner than allow the objectionable matter to ap- 

 pear in it 



My final reference to Principal Forbes was in 61 of the " Forms 

 of Water," where the veined structure of glacier-ice is dealt with. Its 

 description by Guyot, who first observed it, is so brief and appropriate 

 that I quoted his account of it. But this was certainly not with a 

 view of damaging the originality of Principal Forbes. In paragraph 

 474 of my book the observation of the structure upon the glacier of 

 the Aar is thus spoken of : " The blue veins were observed indepen- 

 dently three years after M. Guyot had first described them. I say in- 

 dependently, because M. Guyot's description, though written in 1838, 

 remained unpi'inted, and was unknown in 1841 to the observers on the 

 Aar. These were M. Agassiz and Prof. Forbes. To the question of 

 structure, Prof. Forbes subsequently devoted much attention, and it 

 was mainly his observations and reasonings that gave it the important 

 position now assigned to it in glacier phenomena." 



This is the account of Guyot's observation given by Principal 

 Forbes himself. But it maybe objected that I am not correct in class- 

 ing him and Agassiz thus together, and that to Principal Forbes alone 

 belongs the credit of observing the veined structure upon the Aar 

 Glacier. This may be true, but would an impartial writer be justified 

 in ignoring the indignant protests of M. Agassiz and his companions ? 

 With regard to the development of the subject, I felt perfectly sure 

 of the merits of Principal Forbes, and did not hesitate to give him 

 the benefit of my conviction. 



Such, then, are the grounds of Principal Shairp's complaint quoted 

 at the outset such the " charges " that I have made " against Prin- 

 cipal Forbes," and which the "interests of truth" and "justice to the 



