90 A. M. Mayer—Effects of Magnetization 
gradually elongating under the effects of heat radiated from the 
helix, when the latter has passed through it a powerful current. 
TaBLe II. 
No. of Expt. os “ore Pa ga or on break-| Elongation. | Retraction. 
18 514 52°8 51°8 14 10 
19 51°8 53°2 52°2 14 11 
20 52°2 53°4 52°4 1:2 ll 
21 52°5 53°8 52°7 13 It 
22 52°8 54:0 52°9 12 i 
23 53°0 54°3 53-2 13 Id 
24 53°2 54°5 53°5 1:3 10 
25 53°5 54°7 53°6 1:2 11 
26 53°8 55-2 54 14 10 
27 54°2 55-4 54°4 1°2 1-0 
28 54°4 55°6 54°5 1°2 1‘1 
29 54°5 55°7 12 1-0 
30 54°8 558 54°75 10 105 
31 54°8 56°0 1:2 1-0 
32 55:0 562 12 1:0 
33 5-2 56:3 55°25 11 1-05 
55°25 56°4 115 1-0 
35 “4 56°45 55°5 1:05 0°95 
The. experiments in this table were made on the same 
rod used in the experiments in Table I, but before this new 
series was commenced I passed around the helix a stronger 
current than previously used, so that the rod was elongated, by 
the heated helix, from 39-2 divisions of the scale to 51:4 divi- 
sions, and while the scale was advancing to this reading I deter- 
mined its rate of progress and found it to be 8°6 divisions in 10 
minutes. Therefore these experiments were made on the 
in the two results I thus account for. While the bar was 
slowly expanding from the heat radiated from the helix, the 
circuit was made and the elongation was immediately observed, 
but about five seconds elapsed before the reading could be made, 
and the circuit broken, and during these five seconds the rod 
was expanding, but so slowly that its amount could not be read, 
ut was often visible’ That this minute expansion could not 
be determined was to be expected, for if the rod elongated from 
heat 3°6 divisions in 10 minutes, it elongated only ‘03 of & 
division in five seconds, and -08 of a division was a quantity t00 
a on the scale, but it piserticlon existed 
there, and during the continuance of 18 make-cireuits would 
amount to ‘08 xX 18 = ‘54 of a division; quite an appreciable 
quantity when we come to calculate the mean with this frac- 
