352 CG. KXOTT AND S. KIMUKA. 



same relation to the iiiistrained wire wliich this latter has to the small 

 unaftected wire. The stress, s(i to speak, displaces the liue upwards 

 on the diagram. The eurreiit is acc<3rdiiJLi'ly from the unstrained to 

 the strained ir(jn through the liot junction. On the stress bein,u' 

 renKJN'ed, the wire is left permanently strained, or, as we shall for 

 brevity call it, after-strained. And we sec that for temperatures below 

 lo5°± the current is from the afterstrained to the unstrained throuii'h 

 the hot junction ; but that al)ove 155° tlie current passes in the other 

 direction, 'iliis Avould mean that tlie dia^'ram lines for the unstrained 

 and after-strained wires intersect each other indicating a neutral tem- 

 perature at a tem])erature of 85° oi- tliereab(juts. The directions of the 

 currents as «iven above show that the diai»ram line for the after strain- 

 ed wire is inclined at a less angle to the lead line. Hence the (nega- 

 tive) Thoms(jn Eifect in this particular iron wire is numerically 

 decreased after the application and withdrawal of longitudinal tension. 

 Curves, representative of all tlie experiments whose results are 

 given in Table II., were carefully drawn by free hand on a large scale ; 

 and from these the electronKjtive forces corresponding to particular 

 temperatures were picked «nit. A more pretensious process of inter- 

 polation could hardly ha\e ])een more accurate under the circum- 

 stances ; for the curves, though smooth, liaNc all a distinctly sinuous 

 form, which it would Ik; ditHcult if not impossible to repfesent by an 

 equation of degree lower than the Iburth. The electromotive forces 

 corres])(jnding to convenient temperatures, picked out as just described 

 by ins])ection of the curves, will be fbimd tabulated in Table 111. ; and 

 in Tahle W. the result (jf subtracting each number in the zero tension 

 coliunn from all tlie others in the same row is shown : 



