382 



On the Compressibility of Solids 



were heated to redness over a Bunsen lamp before use, so that 

 they were thoroughly annealed. The aluminium wire was also 

 heated, though to a much lower temperature, so as to soften 

 it. The other metals were used in the state in which they 

 were supplied. All the wires were straightened, but not 

 stretched, before use. 



The temperature of the wires during the operations was 

 always that of the laboratory, and every care was used to keep 

 it as uniform as possible, and it was as nearly as possible that 

 of the air outside. Working in the middle of winter and in a 

 comparatively high latitude, I hoped to be able to do so in 

 conditions which, as regards temperature, would be similar 

 to those which obtain in the depths of the sea, but the extra- 

 ordinary mildness of the weather this year made it impossible, 

 and the temperatures fell, mostly between 9 and 11 C. 



The results of the investigation are set forth in detail in 

 Tables II to VI, and they are summarised in Table VII. 



TABLE II. Platinum. Date, Jan. 9, 1904. Temperature, 7 C. 

 Wire No. 22 S.W.G. Length, 75-35 inches. 



In the summary, Table VII, the compressibilities of English 

 flint glass and of the glass of which ordinary German tubing is 

 made as well as that of mercury have been included for purposes 

 of comparison. The compressibility of mercury rests upon a 

 large number of observations made in the "Challenger," 1 by 

 1 Chem. Sac. Jour. (1878), vol. xxxm. p. 453. 



