HOLMAN. 



THERMO-ELECTRIC FORMULA. 



201 



TABLE II. 

 Barus's Air Thermometer Comparisons, Series I.-V. 



The Avenarius equation applied to these data yields 

 2^6 = 9.104 < + 3.249-10-='^2_ 



Microvolts. Eange 350° to 1075° C. 



Computing from this equation values of SJe for the successive 

 values of t in column one, and subtracting them from the data in 

 column three gives the deviations between data and equation. These 

 are expressed in microvolts in column four, and in percentages in 

 column five, the percentage being reckoned in terms of Cf as deduced 

 by the exponential formula. Objections may be felt to this use of e^ 

 (here as throughout the subsequent tables) as a basis, since e^ involves 

 Co, which is an extrapolated value, certainly not exact, and possibly 

 wide of the truth. Such a criticism is valid, but inasmuch as the values 

 of ^0 employed are nearly equal, and as the percentage deviations are 

 used merely for purposes of expressing relative accuracy, the possible 



