Thermo-electric Effects of Longitudinal 

 Tension in Different Metals. 



By 



K. Tsuruta, Rigakushi. 



Assist. Prof, of Physics, Science College. 



With Plate IV. 



§. 30. Having investigated the general features of the phenome- 

 non of thermo-electric hysteresis with respect to longitudinal tension 

 in iron, I proceeded to examine it in other metals. Measurements of 

 a comparative order had been long since amassed and now it only 

 remained to express them in absolute measure. One of the principal 

 things to be measured is the thermo-electric E. M, F. produced, and 

 of several methods available, one of the most practical, and indeed 

 that adopted by Prof. Ewing, (,) is to determine the constant of the 

 galvanometer by passing through it a known and, at the same time, 

 constant current and then to calculate the E. M. F. by finding the 

 resistance of the circuit. 



It was therefore necessary first to investigate how the resistance 

 changes when the metal under test is subjected to a varying longitu- 

 dinal tension. The metal, consisting of stretched and unstretched 

 parts, together with the leading wires, was put in the fourth arm of a 

 standard resistance box. After the resistance had been determined in 



(1) Prof. Ewing, Thermo-electric Quality of iron, 1. c, § 20. 



