in changing the dimeusions of Lron and Steel bars. 89 
TABLE I. 
No. of Expt. macs a Remee — god gat ae ea vt Elongation, | Retraction. 
1 376 39°2 38-0 16 12 
2 38°0 39°2 38°0 1:2 t Me ay 
a 38°0 39°2 38°0 1°23 1:3 
4 38°0 39°2 38°0 12 1:2 
5 38-0 39°2 38-0 1:2 1:2 
6 38-0 39°2 381 13 pee 
vi 38-1 39°3 38°1 1°2 12 
8 38-2 39°4 38°3 12 it 
9 38:3 39°5 38°4 12 5 be 
10 38-4 39°55 38°6 1°16 0°95 
ll 38°6 39°6 38° 1:0 ae Se 
1 38: 40°0 38°85 14 oT aS 
13 38°85 40°71 39°0 1°25 11 
14 39 40°2 39°1 1°2 Si 
15 39:1 40°2 39°2 14 1-0 
16 39°23 40°3 39° ll 1 
17 39°2 40°4 39°3 12 13 
about 5 seconds, and observed a retraction of 1-2 div. ; the rod 
now remained at a constant temperature for three hours and 
the scale-reading remained steady at 88-0; thus showing that 
the rod had received a permanent elongation of “4 of a division 
on receiving its charge of residual magnetism. On repeating 
the scale remained immovable. Taking 1°2 div. as the amount 
gation % experiments 6-17 is 1°18 div. This is only 02 of 
an | 
temperature it had during experiments 1-5, we found that it 
op ually retracted until the scale again remained steady at 38°0. 
f able IT is here given to show that nearly the same effects 
% elongation and retraction are observed when the rod is 
