650 Messrs. W. Morris Jones and J. E. Malam on the 



was the instrument shown in fig. 1. By means of this 

 arrangement the difficulty of accurate setting is obviated. 



Fig-. 1 



SCALE FOR 



ROTAT/OM/N 

 f/OR/ZOHTAL PL/WE 



Scale for 



ROTATION tN 



Vertical Plane 



Copper Leads oa £boa//te stem 



Pole P/eces. 



The instrument is so constructed that when once^ the 

 necessary adjustments have been accurately made the middle 

 point of the specimen will remain at the common vertex 

 of the conical pole-pieces during any rotation. The spe- 

 cimen, in the form of a fine wire of length *361 cm. and 



