48 Prof. Tyndall's Notes or Scientific History. 



ance and disappearance of bright stars, and the strange variations 

 of brilliancy of others which have caused so much astonishment." 

 (Phil. Mag. vol. viii. p. 415). Three years previous to the 

 publication of the above paragraph Dr. Mayer wrote thus : — " It 

 is more than probable that the earth has come into existence in 

 some such way, and that in consequence of this process our sun, 

 as seen from the distance of the fixed stars, exhibited at that 

 epoch a transient burst of light. But what took place in our 

 solar system perhaps millions of years ago, still goes on at the 

 present time here and there among the fixed stars; and the 

 transient appearance of certain stars, which in some cases, like 

 the celebrated star Tycho, have at first an extraordinary degree 

 of brilliance, may be satisfactorily explained by assuming the 

 falling together of previously invisible double stars." (Bemer- 

 kungen ii. d. mech. Aequiv. d. Warme, p. 56 ; Phil. Mag. vol. xxv. 

 p. 521.) 



57. At the commencement of his paper " On the Mechanical 

 Energies of the Solar System," Prof Thomson states that this 

 theory was never brought forward in any definite form, so far 

 as he was aware, "until Mr. Waterston communicated to the 

 British Association at Hull a remarkable speculation on cosmical 

 dynamics (Dynamik des Himmels), in which he proposed the 

 theory that solar heat is produced by the impact of meteors." 

 Mayer is here definitely ignored ; and I assume the reason to 

 be the same that I have assigned for Prof. Thomson's silence 

 regarding Mayer's writings on vital dynamics. But he was not 

 left without information ; in my lecture in June 1862 I referred to 

 those writings in the following words : — " In 1853 Mr. Waterston 

 proposed independently the meteoric theory of the sun's heat, 

 and in 1854 Prof. Wm. Thomson applied his admirable mathe- 

 matical powers to the development of the theory ; but six years 

 previously the subject had been handled in a masterly manner 

 by Mayer, and all that I have said on this question has been 

 derived from him." I do not see how I could have stated the truth 

 in more considerate terms. Instead, however, of making him- 

 self acquainted with the essay of Mayer and nobly bidding him 

 welcome, Prof. Thomson permits himself to sanction the following 

 language towards me. c ' Prof. Tyndall is most unfortunate in the 

 possession of a mental bias, which often prevents him (as, for 

 instance, in the case of Rendu and glacier-motion)* from recog- 

 nizing the fact that the claims of individuals whom he supposes 



* I have asked Prof. Thomson to point out the passages in my writings 

 which justify this language, but he has not done so. The readiness of 

 Prof. Thomson to make such statements and to neglect their proof has 

 excited attention in other quarters, and will assuredly furnish him with its 

 harvest of results. 



