TRANSVERSE EFFECT AND ON SOME RELATED ACTIONS IN BISMUTH. 233 



Plate Ib also showed this reversal. For the original plate the following results were 

 obtained : — 



Plate Ib. 



Length, 



Breadth, 



Thickness, 



6-045 



2-58 



0-12235 



cm. 



Field. 



Transverse Effect. 



Sign. 



Rotatory Coefficient. 



8-0 



0-0302 





3-72 



15-1 



0-05276 



- 



3-45 



28-0 



0-05517 



- 



1-94 



38-0 



0-0484 



- 



1-26 



59-0 



0-0218 



- 



0-36 



63-0 



0003 



- 



0-046 



75-6 



0-02229 



- 



0-29 



118-0 



0-14253 



+ 



1-19 



140-0 



0-20239 



+ 



1-43 



148-0 



0-22356 



+ 



1-49 



The transverse effect is first negative ; it increases and reaches its maximum negative 

 effect with field strength 28 (about). Afterwards it decreases and vanishes with field 63 

 (about). It again appears and increases for all other fields higher than 63, but now has 

 the opposite direction. 



This plate was next varied in length and in breadth, but the same thickness was 

 retained ; and the transverse effect was found to vanish for the same field strength. 



The plate was then hammered, and it was found that the transverse effect did not 

 vanish until a field strength of about 80 was reached ; the field strength by which the 

 maximum negative effect was reached was also greater. 



The plate was now made thinner by planing — 



Length, 

 Breadth, 

 Thickness, 



4-47 

 2-08 

 0-0665 



cm. 



Field Strength. 



Transverse Effect. 



Sign. 



Rotatory Coefficient. 



26-0 



0-21699 





4-48 



38-0 



0-22231 



- 



3-14 



49-0 



0-21172 



_ 



2-32 



62-0 



0-13521 



— 



1-17 



87-0 



0-4749 



— 



0-29 



97-0 



Not Observed. 







101-0 



0-0376 



+ 



0-199 



117-8 



0-17013 



+ 



0-77 



135-0 



0-27122 



+ 



1-08 



145-0 



0-33084 



+ 



1-22 



VOL. XXXVIII. PART I. (NO. 6). 



2 I 



