AKT. 14.— K. HONDA AND S. SHIMIZU : 



The prelimiiJîiry experiment showed that the resistance to the 

 twist ottered hy the mercury in tlie jiool was not negb'gibly small, 

 when tlic thick brass wire was dipped into the mercnry. The resis- 

 tance was especially noticeable, wdien the brass wire carried a narrow 

 rectano-ular piece for the purpose of damping. Hence in order to 

 efface the resistance, a non-magnetic nickel steel wire 0.5mm. thick 

 and 5cm. long was soldered to the lower end of the brass wire and 

 dipped into the mercury pool, liy this, the damping of the torsional 

 oscillation was rendered very small, especially in the case when a 

 weio"ht was attached. To stop the oscillation, a brass wire was fixed 



horizontally to the vertical wire and 

 bent downward as shown in the 

 annexed figure. Just below it, a 

 small mercury cup was placed ; this 

 (jup was connected with a large one 

 by a caoutchouc tube. This large 

 cup was placed near the observers and 

 could be raised or lowered by means 

 of a screw adjustment. This motion 

 caused the mercury in the small cup 

 to be raised or lowered, so that the 

 side wire dipped into the mercury, 

 <:)r hung free. When we wished to 

 stoj) the oscillation of the wire, the 

 side wire was dipped into the mercury in the small cup ; while the 

 reading was always taken with the wire hanging free of the mercury. 

 The experiment was conducted in the following manner: — 



1. The circularly magnetizing current Avas kept constant, 

 and the amount of twist measured bv varvinçr the 

 lono-itudiiiallv mannetizins' current. 



K 



