ON CERTAIN THERMOELECTRIC EFFECTS OF STRESS IN IRON. 347 



iron Avire were so nrrancfed tlint the temperatures of two successive 

 posirions difl'ered l)y 40°-60° ('. Tlie ]):iir:-; of junotious were distin- 

 guished hv iiumlter, Xo. T. Ijcinu' tlie hottest niid Xo. V. the coldest. 



The o])serv:itioiis were in:i(h' in tlie f )llowinü' order. First, tlie 

 five thei'nionietric curi'ents wei'e measured in ra])id succession i'roui T. 

 to y., eacli ciu'i'ent Ix'ing" measured first in tlie one and then in the 

 other direction throuu'h the galvanometei'. [This was an invariable 

 rule in the measurement of ;dl currents, the total ran^'e from the 

 direct to the reverse reading- <i'ivinu- twice the true deflection.] Then 

 followed a simi]:u' set of reading's of tlie fi\'e thermoelectric currents ; 

 then a secoiid set of tlie thcrmoinctiâc ; and so on until 4 sets of tlie 

 thermometric currents witli o iiiterpofsted sets of the thermoelectric 

 currents had l)een comjtleted. Kxactly similar sets of ohservations 

 were made for the series of tensions re])resenting t(^tal loads of 0, 5, 

 10, 15, 20, 24 and pounds. Ke(hice(l to kilou'ram-weiu-ht per square 

 millimetre, these tensions are a little L'Tcatcr than 0, 2, 4, G, (S, 9*6, 

 and respectively. 



In Tal)le T, the ohservations are given in full ior the üve ])airs of 

 junctions ; T stan(hng for the thermometric junctions wliose indica- 

 tions form an arbitrary tem])erature scale, and E f n- the thermoelectric 

 junctions whose e]ectr(^motive forces are the real sul)jects of investiga- 

 ti(^<n. Tlie tensi(^n, the temperature of the cold junctions, and the 

 factor fn- reducing tlie deflections to electromagnetic units of electro- 

 motive fn'ce, are given in the space to the left of the tal)ulated numhers. 



