196 Mr. C. Barus on Maxwell's Theory of the 



("An."), and the electrical constant* (specific resistance .<? , 

 microhms, c.c, 0° C), as well as the differences s —s f and 

 5 100 — s' 2 o? m which the subscripts are the temperatures at 

 which s is taken, and s' is the constant of the normal rod 

 No. 1. Hence these electrical differences correspond to 

 ($-<!>') /t, when = 0° C. and 0=100° C. respectively. For 

 No. 1, therefore, 5 , = 13'6 ; s' — s = and <j> — <p'/r=0. 



The values (<£ — <£') /t are in the same horizontal row with 

 the temperature 6 to which they belong. 



Table II. 



Values of— — — X 10 3 at different consecutive 



times. 



No. 



31-3 



0-8 

 5-9 

 0-6 

 5-6 



0-4 

 5-5 

 1-5 

 6-5 



10-2 

 15-8 

 123 

 17-7 

 12-7 

 17-8 



18-6 

 24-2 

 15-6 

 210 

 149 

 20-5 



20-8 



184 



22- 1 



20 

 100 



20 

 100 



22 



100 



23 



100 



19 

 100 



20 

 100 



20 

 100 



19 

 100 



20 

 100 



21 

 100 



20 



20 



20 



Time 



2 m . 



5 m . 



10m. 



20m. 



30m. 



40«». 



50 m . 



-0-00 



- -04 



-•07 



-10 



-•12 



-•14 



-•15 



4-0-00 



4- -82 



1-65 



2-76 



3-63 



4-26 



4-84 



-0-00 



- -09 



-•18 



-•28 



-•34 



-•38 



-•40 



4-0-00 



+ 1-69 



2-90 



448 



5-75 







o-oo 



•21 



•50 



•82 



100 



1-09 



117 



000 



2-32 



4-70 



7-05 



8-70 



9-80 



10-80 



o-oo 



•11 



•25 



•37 



•43 







000 



1-65 



2-90 



4-60 



5-88 







000 



•09 



•18 



•23 



•23 







o-oo 



4-40 



11-00 



18-70 



23-30 



2640 





000 



•67 



1-27 



1-90 









o-oo 



7-50 



16-30 



26-50 



32-20 



36-50 





o-oo 



•21 



•49 



•83 



•98 







o-oo 



9-00 



19-00 



30-20 



36-70 



41-30 





o-oo 



•44 



•98 



1-74 



2-26 







o-oo 



25-70 



48-50 











000 



•63 



1-25 



200 



2-48 



2-84 





o-oo 



20-50 



4100 



69-50 









o-oo 



•47 



TOO 



1-57 



1-90 



2-14 



2-33 



000 



13-00 



28-50 



48-00 



61-50 







o-oo 



3-50 



615 



8-83 



10-75 







000 



1-67 



3-29 



5-15 



6-35 







o-oo 



3-10 



5-80 



8-50 



1015 



11-46 





7. Before proceeding to a discussion of the results in 

 Tables I. and II., I will insert a few introductory data which 



* For definition of thermo-electric hardness see Bull. U.S. G. S. 



no. 14, p. 65 (1885). 

 the above. 



and s. 20 — s' 20 need not be distinguished in 



