442 



the Kelvin scale for this hydrogen tliermometei' [puK\ = 120 o.in.) 

 (4_0.14 down to —253°, +0.15 for —254° and —255°, +0.16 

 for —256°, +0.17 for —257°, +0.18 for — 258°, + 0.20 for 



259°) were deduced down to —257° from the corrections of the 



scale of the international hydrogen thermometer found for this region 

 by Kamerlingh Onnes and W. J. de Haas, Comm. No. 127c (June 

 1912), those for the lower temperatures were calculated according 

 to the research of Kamerlingh Onnes and Holst mentioned above. 

 75.95 cm. of mercury v^as adopted as the international atmosphere ^) 

 at Leiden. 



§ 3. The results are given in the following table. 2) 



The difference 0.03 cm. between the values of the pressure found 

 at — 256°.08 with much and with little liquid corresponds to a 

 difference in temperature of 0.003 of a degree and lies within the 

 limits of accuracy; moreover it is in a direction opposite to that 



1) Gf. H. Kamerlingh Onnes and W. H. Keesom. Math. Enz. V 10, Leiden 

 Comm. Suppl. N». 23 Einheiten a. 



~) The numbers given in this table, and those derived from it further on in 

 this paper differ slightly from those given in the Dutch edition in accordance with 

 the slightly altered values of the corrections to the Kelvin scale (cf. 441 p. note 7) 

 and an improved calculation of the temperatures. 



