534 THE LIFE OF JAMES D. FORBES. [APPEND. 



would have been satisfactory to himself. 1 Nearly all of them 

 depend on the reported estimates of the guides, who are too well 

 known (with rare exceptions) to affect an accuracy of knowledge 

 in such matters of which they are who^Jy destitute, and even (I 

 am sorry to say) to frame their replies in the sense which they 

 believe will be most in conformity with the ideas of their em- 

 ployers for the time. 2 



The estimates of MM. Hugi and Agassiz, which might seem 

 to form exceptions, left the question in almost a worse position 

 than ever, for the velocities which they measured in the same 

 region of the same glacier differed in no less a proportion than 

 one to three* The chief error proved to be in the larger number, 



ilf the reader will turn to pp. 37, 127, 128 of my Travels, he will find 

 reasons given for my scepticism in several instances. Thus, at p. 37 ' It 

 seems very singular that ingenious men, with every facility for establishing facts 

 for themselves, should have relied on conclusions vaguely gathered from un- 

 certain data, or the hazarded assertions of the peasantry about matters in 

 which they take not the slightest interest.' These remarks, though not re- 

 ferring primarily to the statements of Uendu, are, as we shall see, applicable 

 to them also. 



2 Before the time of Hugi (see Alpenreise, p. 371, cited in my Tr 

 p. 127) it was a common error to confound the actual movement of the ice with 

 the amount of the advance in cold seasons of the lower termination of a glacier 

 into the inhabited valleys, a circumstance evidently of infinitely more moment 

 than the other to the native peasantry. 



8 Cited also on the same page of my Travels. The table quoted by Pro- 

 fessor Tyndall at p. 305 omits M. Agassiz' most irreconcilable estimate, that of 

 2,200 feet in three years, or 733 feet per annum Hugi's estimate having been 

 only 244 feet per annum. M. Agassiz accepted this enormous irregularity of 

 motion (since admitted to be a mere mistake) in these words : ' II rdsulte de 

 ces faits que nendant les trois dernieres anne"es le glacier a fait autant de chcinin 

 que pendant les dix [neuf ?] premieres. Ce qui semble indiquer une marche de 

 plus en plus rapide a mesure qu'il avance vers la vallee.' (Etudes sur Us 

 Glaciers, p. 151.) Yet this last conjecture is annihilated by the statement 

 which follows in the next sentence but one, that the motion for one year (1 s !') 

 posterior to all the ^thers was only 200 feet ! In such confusion of fact and 

 inference was this subject when I rntered upon it. 



I must here add that Professor Tyndall has referred in several places to M. 

 Agassiz having made measurements similar to mine (in 1842), contempora- 

 neously or nearly so. That Professor Tyndall should have remained unaware 

 (as he indicates at n. 274) of the measurements made by M. Agassiz in 1842, 

 imtil Professor "Whcatstone referred him (apparently quite recently) to the 

 Comptes Rendus, is to me a matter of the utmost surprise. Not only are the 

 observations detailed, and that work cited, in M. Agassiz' Nouvelles Etudes, 

 which Professor Tyndall might have been expected to consult, but they are 

 specially referred to in an article in the Westminster Review, for April 

 1^57, in which Professor Tyndall can hardly have failed to recognize the hand 

 of a zealous supporter of his own. In that article, while justice is at the same 

 time done to Kendu, every possible advantage is allowed to M. Agassiz ; but 

 the writer records an impartial decision in favour of my priority (T/ 

 Review, New Series, Vol. XI. p. 427). The measurements of M. Ag 

 moreover (as I have indicated at p. 37 of my Travels in the Alps), were made 



