39 
Ordinary Meeting, November 17th, 1868. 
R. Angus Smith, Ph.D., F.R.S., Vice-President, in the 
Chair. 
Mr. John Isaac Mawson, C.E. ; and the Rev. Brooke 
Herford, were elected Ordinary Members of the Society. 
Professor William Jack, M.A., laid on the table Professor 
Tait’s new work on Thermodynamics, presented to the 
Society, (of which he is an honorary member) by the author. 
He called attention to the estimation in which Professor 
Tait held the work of Hr. Joule in laying the foundations of 
the science. It was well known that the claims of Mayer 
to the first place in connection with the subject were 
strenuously advocated by some authors. Professor Tait 
considered those of Hr. J oule incomparably superior. 
The equivalence of a definite quantity of work to a defi- 
nite quantity of heat had been indicated as extremely 
probable by the experiments of Rumford ; and Havy’s cele- 
brated experiment, in which he melted ice by friction, con- 
firmed the view that work was really so convertible, 
Modifications of Rumford’s experiments would have enabled 
him to present the heated body in nearly the same state 
after as before heating, except as regarded the increment of 
temperature. These, however, had not been made, and the 
experiments appear to have been neglected. 
In all heating there are three mechanical results of work 
possible : 
1. That the particles of the body may be set into more 
rapid vibration. 
Proceedings — Lit. & Phil. Society. — Vol. YIII. — No. 4. — Session 1868-9. 
