467 



Measurement I: 102.875 cc. 

 Il: [J02.817] „ 

 III: 102.874 „ 



Tn taUing the mean the second measuremejit was given lialf the 

 weight of the otiier two, on the ground tiiat i1 does not agree well 

 with the others and that an irregularity must have occurred in it, 

 as was also clearly shown by a discussion of the observed temperature, 

 pressure and barometer in connection with each other. The mean 

 was thus taken at 102.863 cc. 



3. Results. These are collected in Table II. Tiie pressures are 

 given in international atmospheres (75.9488 cms. mercury at Leiden), 

 in the densities (r/.i) the normal density and in the volumes (w.i) t'le 

 normal volume is taken as unit. 



As regards the representation of these observations by a series 

 with ascending powers of (/.i ') the (juestion arose as lo vvhetiier 

 they could be represented by Schai.k\vi.jk's formula for 4 lo 60 

 atmospheres 



pvA — 1.07258 + ü.667i X 10-3 <.i _^ 0.993 >< 10-6<:/.i''' 

 in other words, whether Schalkwtjk's formula, which holds up to 

 60 atmospheres, could be extrapolated as far as 100. 



^) H. Kamerlingh Onnes, These Proceedings 4, p. 175, 1901. Coram. N". 71. 



