﻿414 



Messrs. K. Sclieel and W. House on the 



Table I. 

 Specific volume o£ water with respect to that at 4°. 



Temperature. 



Alean Value. 



Variations from the Mean Value Xl0 6 . 



Chappuis, 



Verre clur. 



Chappuis, 

 Platinum 



Iridium. 



Thiesen, Scheel rrl • r P , . ,, 

 & Diesselhorst , f hl f er \ rbies . e P ^y 

 (absolute). (absolute), weighmg). 







10 



20 



30 



40 



100 



1-000132 



1-000 272 

 1-001771 

 1-004 343 

 1 007 814 

 1 -043 422 



-1 

 -1 

 -3 

 -4 

 -6 



-1 

 _2 



-1 



-i 

 







+ 1 



:: 



+ 5 



* 

 ... 



+11 



+ 1 



+ 1 



+2 

 + 4 



4. In the Reichsanstalt observations on the relative 

 expansion of mercury in the Jena glasses 16 m and 59 111 and 

 also verre dur have been made between 0° and 100° by 

 means of the weight thermometer method *. For the 

 calculation of the absolute expansion of mercury use was 

 made of the measurements of the linear expansion of one 

 metre long rods of the same classes which were placed on the 

 comparator at 0°, 25°, 50°, 75°, and 100°. This calculation, 

 however, was through cautiousness only applied to two 

 dilatometers, those from the glasses 16 UI and 59 m , since it 

 was only with these two that there seemed to be sufficient 

 guaranty that the dilatometer and glass rod were composed 

 of the same material, Especially certain was the case of 

 glass 59 HI , since the dilatometer tube and capillary were 

 furnished at almost the same time from the glass-works and 

 so very probably originated from the ?ame melting. For 

 glass 1G 111 there still remains in this respect some doubt. 

 On this point one of the conclusions drawn in the paper 

 cited is in particular to be considered, namely, "that the 

 Jena glass 16 UI does not present sufficiently homogeneous 

 properties for drawing any further conclusions.''' For this 

 reason in the following Table IL for the expansion of mercury 

 only those values obtained from the observations on the 

 Jena glass 59 Tn dilatometer are given without reservation, 

 while those results obtained from the dilatometer of glass 

 1G 111 are placed in parentheses. 



the same method as Chappuis the mercury 



By using 



* M. Thiesen, K. Scheel unci L. Sell, Wiss. Abh. d. Plnjs.-Techu. 

 Reichsanstalt, ii. pp. 73-184 (1895), especially pp. 160-163. 



