1904.] Thermoelectric Power produced by Magnetisation. 



433 











(PL_ 



















//<Q) / 

 /P 























400 



c 



100.0 



200 



300 



400 500 

 Magnetic Field. 



600 



FiG. 9. — Curves (P) and (Q,) show changes of thermoelectric force in an annealed 

 nickel wire when loaded respectively with 970 and 447 kilogrammes per sq. cm. 

 Curves (0) and (p) show changes of length for an unannealed wire when 

 loaded with 980 and 420 kilogrammes per sq. cm. 



Cobalt. — Experiments are made with two different specimens of 

 cobalt, the results being given in fig. 10. 



Fig-. 10. — (R) and (S) show thermoelectric changes for cast and rolled cobalt 

 respectively ; (q) shows changes of length for the cast cobalt ; (r) is the curve 

 of mechanical compression. 



Curve (R), showing thermoelectric changes, relates to a cast rod 

 supplied by Messrs. Johnson and Matthey; the change of length 

 curve (q) was obtained with another piece of the same rod.* 



This latter curious curve is quite unlike the thermoelectric curve (E), 

 * ' Phil. Trans.,' vol. 179, p. 228, fig. 6, 1888. 



