150 Dr. L. Lownds on the Thermomagnetic and 



The direction of the current 3 with respect to the crystallo- 

 graphic axis appears to hare very small influence on the 

 constant C. This has also been observed by van Everdingen* 

 at ordinary temperature. He found at a temperature of 

 15° C. and for a field of 4600 c.g.s. units 0= -8'0, and for 

 a field of 2600 c.g.s. units C=— 10% when the current was 

 parallel to the chief axis. In the other case, using three 

 different plates, he found for 4600 C.G.S. field-strength 

 C=-10'6, -8-8, and — 8*2, and for the field 2600 c.g.s. 

 C= — 12*6, —11*1, and —10*6. These values are of the 

 same order as those found by me. Fig. 6 is obtained from 

 fig. 5 by taking the mean of the values for the two directions 



of 3. ' 



Fisr. 5. 



It is to be noted that at ordinary temperature there is very 

 little dissymmetry in the effect for opposite directions of the 

 field. At low temperatures this dissymmetry is more marked. 

 It appears to vary somewhat with the setting up of the 

 crystal, as will be seen from Table V., which contains readings 

 for two different settings up of the crystal. 



* E. van Everdingen, loc. cit. 



