455 



and also from Comm. N'. 119 ^ 5b Bio^aoK. = — 0,000047 ') ; Table 

 V of Comiii. N*. 156ö! gives a resumé of the corrections, calculated 

 with the above data. In accordance with note 1 and 3, p. 27, 

 Comm. N". 156^ here 5, = 0,000499, i^ioo = 0,000476, «^He = 

 = 0,0036614 are taken, and the influence of the C's is neglected '). 

 New determinations, to be published shortly, of helinm isotherms 

 at 7'= 20°, 5, 4°,2, 3^,7 and 3^,4 K. gave provisional new values 

 for B, which therefore infer the introduction of different corrections 

 in the provisional intern. Kelvin-scale; tliey are lai-ger than those in 

 Table V, Comm. N". 156a and they do not come into line so well 

 with those for higher temperatures. For the sake of completeness 

 we give a comparison of these in Table 1. (cf. p. 387). 



^ 4. Temperature of the vanishing point. On May 18^'i and 28^'! 

 1920 all three resistances proved superconducting in liquid helium 

 and behaved, therefore, in the usual way. After this the cryostat 

 was gradually brought to a higher temperature by electric heating 

 of the vaponsed helium. At a certain moment the galvanometer 

 moved qjiicklj over 35 cm. on the scale and the vanishing point 

 was apparently reached; the suddenness of the deflection speaks 

 well for the usefulness of the cryostat if not too high demands are 

 put upon it. A repetition of the heating (very gradually) confirmed 

 the first result. While the temperature was kept constant the thermo- 

 meter was read at the vanishing point. The results are given in Table III. 



TABLE III. 



J3 



ij The B= —0,000047 is that derived according to pv --^ RT -\ ; the B's 



further mentioned in this number are those according to j^v = RT 



0^f> 



agreement with the change of notation mentioned in note 360 of Comm. Suppl. N**. 23. 

 ') These values for Bq, Sjoo and xifje must be retained to get the corrections 

 on tlie provisional internat. Kelvin-scale. Measurements have sliown that it would 

 have been more correct to use Bo = 0,000513, Bk^^, = 0,000id2 and x,//e = 

 0,0036618 (Comm. W. 102Ö, Table I and Com. N«. 156a, p. 22, note 1); this 

 would lead to a second provisional intern. Kelvin-scale (helium-Avogadro-scale) for 

 which reason we retain the first B'a. 



