Adams and Johnston — Standard Scale of Temperatures. 539 



hand and between the freezing point of cadmium and the 

 benzophenone point on the other, — using our own apparatus and 

 materials — which were 0'2° higher than the corresponding dif- 

 ferences obtained by Waidner and Burgess at the Bureau of 

 Standards. This lack of agreement disappeared* when we 

 determined all the points on the identical samples of material 

 used by Waidner and Burgess. This we were enabled to do 

 through the kindness of Dr. (1. K. Burgess in lending us his 

 boiling point apparatus and his pots of tin, cadmium and lead, 

 and we desire here to acknowledge our indebtedness to him. 



Table III. 

 Boiling Point of Naphthalene and Benzophenone. 



Sub- 

 stance 



Naph- 

 thalene 



Benzo- 

 phe- 

 none 



Source 



Merck 

 Kahlbaum 



Kahlbaum 

 Merck 



Merck (b) 



(a) 



(b) 



Ap- 



Thermo- 



paratus 



couple 1 



A 



E 



B 



E 



B 



C- 



A 



C 1 



(■ 



c 3 



a 



c 2 



A 



E 



a 



« 



S ' 



c, 



A 



c, 



S 



c, 



A 



c 3 



« 



c, 



From Thermoelectric 



measurements 

 (Adams & Johnston) 



Microvolts 



1585-f 4 ] 



1585-3 



10119- 



10119' 4 



10118*5 



10120- j 



2366-2 ] 



2366*3 



15008- 



15007- 4 l 



15010- 



15004- 



15005-5 4 j 



Degrees 



(217-95) 



(306-1 



From Eesistance Ther- 

 mometer measurements 

 (Waidner & Burgess) 



As given 

 by them 2 



218-0 



306*2 



When re- 

 duced to our 

 scale 3 



217-97 



306-11 



1 Couple E is of Pt— PtRh; Ci, C a , C 3 , are of copper-constantan. 



2 Bull. Bur. Standards, vii, 4, 5 (reprint No. 143). 



3 The values given in the last column have been reduced from those in the 

 column to the left by means of the differences between the scales as deter- 

 mined in a way to be described later (p. 543); i. e., these values are on the 

 basis that the b. p. of sulphur is 444 55°. 



4 Mean of two or more determinations often separated by a monthor so in 

 time. The maximum deviation from the mean in any of these cases was 

 0-03°. 



* The divergence was due to slight impurities in our tin and to the fact 

 that the benzophenone used was from Merck (cf. footnote to Table I). 



