108 JOULE'S ACCOUNT. 



suggested that, as the business of the Section pressed, I 

 should not read my paper but confine myself to a short 

 verbal description of my experiments. This I endeavoured 

 to do, and a discussion not being invited the communi- 

 cation would have passed without comment if a young man 

 had not risen in the section, and by his intelligent observa- 

 tions created a lively interest in the new theory. The 

 young man was William Thomson, who had two years 

 previously passed the University of Cambridge with the 

 highest honour, and is now probably the foremost scientific 

 authority of the age." 



Writing to Mr. J. T. Bottomley in 1882 {Nature, Vol. 

 XXVL, p. 618), Sir William Thomson also writes of this 

 meeting : — 



" I made Joule's acquaintance at the Oxford Meeting, 

 and it quickly ripened into a life-long frendship. I heard 

 his paper read at the sections, and felt strongly impelled to 

 rise and say that it must be wrong, because the true 

 mechanical value of heat given, suppose to warm water, 

 must, for small differences of temperature, be proportional 

 to the square of its quantity. I knew from Carnot's law that 

 this must be true (and it is true ; only now I call it 

 * motivity,' in order not to clash with Joule's ' Mechanical 

 Value '). But as I listened on and on, I saw (that though 

 Carnot had vitally important truth not to be abandoned) 

 Joule had certainly a great truth and a great discovery, and 

 a most important measurement to bring forward. So instead 

 of rising with my objection to the meeting, I waited till it 

 was over and said my say to Joule himself at the end of 

 the meeting. This made my first introduction to him. 

 After that I had a long talk over the whole matter at one 

 of the conversaziones of the Association, and we became 



