698 Prof. E. P. Adams and Mr. A. K. Chapman 



Aluminium. — On account of the difficulty of soldering 

 aluminium, the disk, ring, and central rod were turned out 

 of a solid piece. The ring and rod were threaded so as to 

 screw to the brass plate and the central copper wire. The 

 effect was small and of the same sign as copper. The average 

 of a number of determinations gave : 



H 



H. 



n. 



n 



7968 



14-4 



553 



6850 



111 



617 



5665 



no 



515 



Average ... 562 



Bismuth. — The bismuth disk was cast from chemically 

 pure bismuth and turned down to the proper dimensions. 

 The effect was very large, the same sign as copper, and it 

 increased less rapidly than the magnetic force. This was 

 the only metal in which certain departure from propor- 

 tionality between the circular current and the magnetic 

 force was found. The effect was too large for the calibrated 

 mutual inductance used with the other metals, so that a 

 larger one had to be employed for the larger values of the 

 magnetic force. 



*■ 



7725 6922 1-116 



6540 6368 1-027 



5819 6055 0-961 



4686 5721 0-819 



2626 3778 0-695 



953 1491 0-639 



419 755 0-555 



107 539 0-577 



30 50-2 0-598 



Antimony. — The disk was cast from " chemically pure " 

 antimony in a graphite mould, of the proper dimensions. The 

 effect was opposite in sign to copper, and. appeared to be 

 proportional to the magnetic force. 



7210 



634 



n 



11-4 



6180 



555 



11-1 



4377 



417 



10-5 



2595 



248 



105 



Average ... 10'9 



