Manchester Memoirs, Vol. xlviii. (1903), No. 3. 7 



The Calorimeter. 



The calorimeter was of very simple construction, and 

 is shown in section in Fig. i. It consisted of three coaxal 

 metal cylinders, the innermost containing water, the other 

 two ice and v/ater (to the levels indicated in the diagram). 

 For better insulation the whole arrangement was supported 

 at a few points within a wooden box. The water in the 

 innermost vessel was frequently stirred (stirrer omitted in 

 the diagram), A wire-gauze tray (not shown in the 



Fig. 1. 



diagram), hanging from the rim of the containing 

 vessel, dipped below the surface of the water ; this con- 

 tained ice. This tray was removed for the insertion of 

 the cold object in the calorimeter, but was replaced as 

 soon as possible ; it was so constructed as not to interfere 

 with the suspension of the object. It was unfortunately 



experiments the cylinder was cooled in the liquid air with its curved surface 

 and base protected in this manner from contact with the liquid air ; the cover 

 was rapidly withdrawn immediately on removing the cylinder from the 

 liquid air ; these experiments gave respectively '0799, "0797, "0802, mean 

 •0799, or practically the same number as when the cover was not used. 

 These results show that the amount of adhering liquid air (small in the last 

 three experiments, relatively large in the first five) may be considerably 

 varied without much influencing the result. 



