505 



The readings of Pti allow a coinparison with the measurements 

 of 1906—1907. 



W 



In (if>-. 1 the deviations from the linear formula ^==: - 243 4-243 



are represented for all three calibrations, at temperatures above 

 — 217° C. The circles refer to the calibration of 1913, the triangles 

 to 1907 and the S(|iiares to 190(>. For the calculation of temperatures 

 in this field the above formula with the deviation curve l)clonging 

 to it has been recently used in the Leiden researches. 



