346 Von Tunzelmann on the Production of Thermoelectric 



10 -8 C.G.S. unit. The measurements of the Tables are given 

 in millionths of a C.G.S. unit. 



Experiment^. — A similar steel wire. © = 16°. Initial de- 

 flection barely perceptible S.U. Weight of 30 lbs. left on 

 about 40 hours. 



It was observed that at the time of making the experiment 

 the weight was making small oscillations; and this appeared 

 to be the cause of the deflections making small oscillations 

 about a mean value. At the end of an hour and a half the 

 oscillations of the weight and also of the deflection had ceased, 

 the latter remaining steady at 5, indicating a current *007 

 U.S. The weight was now made to perform vibrations of 

 small amplitude, upon which the oscillations of the deflection 

 were greatly increased both in number and amplitude, and 

 the mean deflection was at the same time somewhat increased. 

 If the vibration of the weight be suddenly stopped, it is some 

 little time before a decrease is perceived in the oscillations of 

 the deflection. 



After setting the weight in gentle vibration, the effect in 

 causing oscillations in the deflection was observable in less 

 than a minute. If the vibrations of the weight are kept up 

 for some time, the mean deflection is increased up to a certain 

 limit, as before described. If the vibrations of the weight are 

 increased in amplitude, the oscillations of the deflection become 

 -much more irregular, and the limits of variation become 

 greater. 



Experiment 7 . — A similar wire. © = 12. Initial current *0014 

 U.S. A weight of 3 lbs. was now attached ; and at the end of 

 two minutes there was a current '0052 S.U., falling at the 

 end of an hour and a half to "0034 U.S. The weight was then 

 increased by 3 lbs. at a time and the deflections taken immedi- 

 ately, with the results given in the accompanying Table: — 



w. 



0. 



Direction 



6 . . . 



. . -0038 



U.S. 



9 . . . 



. . -0019 



U.S. 



12 . ■ . . . 



. . -0014 



U.S. 



15 . . . 



. . -0012 



U.S. 



18 . . . 



. . -0012 



U.S. 



21 . . . 



. . -0012 



U.S. 



24 . . . 



. . -0012 



U.S. 



27 . . . 



. . -0010 



U.S. 



30 . . . 



. . -0002 



U.S. 



33 . . . 



* 



S.U. 



In the experiments after this the weights are given in terms 

 of measures of shot, each of which weighed about 7480 grains. 



