1895.] in the Magnetic Permeability of Iron. 



FIG. 1. 



227 



ceivably be caused by alterations at the joints, a rectangle was made 

 up as follows : 



A number of iron plates were taken, each 16J ins. by 11 ins. 

 by 0'014 in., there being stamped out from the middle of each plate 

 a piece 11 ins. by 5J ins., as in Fig. 2, showing side and edge views. 

 The plates were separated by paper and bound together by tape. 

 They were then overwound, as in the figure, with a continuous wind- 

 ing, consisting of 140 turns of insulated copper wire 0'049 in. 

 diameter (resistance 0'4 ohm) so disposed as to magnetise the block 

 almost evenly throughout the magnetic circuit. 



The measurements made with this sample are given in Table "V 

 and Diagram 5. 



