TABLE 239. 



EFFECT OF COMPOSITION ON THERMOMETER ZERO.* 



Jena Glasses. 



TABLE 240. 



CHANCE OF ZERO OF THERMOMETER WITH TIME. 



Closely allied to the changes illustrated in Tables 235-237 is the slow change of volume of the bulb of a thermometer 

 with age. The following short table shows the change for the normal Jena thermometer.J 



SMITHSONIAN TABLES. 



* Fresenius, " Zeits. fiir Anal. Chem." vol. 27, p. 189. 



t Normal Jena glass. 



Z Allihn, " Zeits. fiir Anal. Chem." vol. 29, p. 385. 



231 



