38 



K. TSUKUTA. 



and then removed or vice versa, the thermo-electric E. M. F. goes 

 through almost the same series of values. 



§ 12. The next group of my experiments relates to the effects 

 of agitation, which, as was shown first by Prof. Ewing, (,) are very 

 strikingly manifested in largely destroying the effect of the hysteresis. 

 As an instance, take the following experiment on annealed iron wire 

 0*54 m.m. in diameter : — 



Loaded up to 3 kilos., the wire was agitated by briskly tapping 

 with a piece of wood the string over the pulley by means of which 

 the weights were hung on. The reading which was about 20 divi- 

 sions before agitation was found to be reduced after it to only about 

 9 divisions. When on the "off" branch the wire was under the 

 same load, I again tapped it and found the reading of about 39 divi- 

 sions reduced to about 22. See Fig. 12, PI. II. 



§ 1 3. The wire was, then, agitated each time it was loaded or 

 unloaded and carried through the same cycle of loading and unload- 

 ing (0—1 1—0). The readings taken were as follows : — 



(1) I.e., §14. 



