HOLMAN. THERMO-ELECTRIC FORMULA. 



199 



given by Barus * later, as a basis from which to deduce constants for 

 his jii'oposed equation 



Barus's numerical values for the constants are : 



eg = 45680 microvolts. 

 P = 4.6515 

 F' = 2.849 " 



Q = 1.106 • 10-*. 

 Q' = 3.01 • 10-3. 



These constitute his "equation 3," for which e^ corresponds to 

 20° C. The data and the deviations which I have computed for it, viz. 

 8 = data-equation, are given in Table I. The last column gives the de- 

 viations expressed in percentages, viz. 100 -, where E—e + e^-}- 1880. 

 This value of jE is adopted to make the percentages comparable with 

 those in subsequent discussions. The number 1880 is 1730 -f- 150, 

 which are the. values of e^ and Sq" e of the next two pages. 



TABLE I. 

 Barus's American Jouenal of Science Data. 



The lines ^5 and CD on the diagram (page 212), constructed with 

 percentage deviations as ordinates and temperatures as abscissas show 

 clearly that the deviations are systematic. Upon inspection of this plot 



* Amer. Jour. Sci., XLVIII. 332 (1894). See also XL VII. 366 (1894). 



