developement of magnetical properties in steel and iron, &c. 211 
cess only occasioned an attractive power capable of lifting 
between 56 and 88 grains, though the wire was repeatedly 
hammered, the compound process augmented the lifting 
power, by 12 blows, only, up to 186 grains, indicating three 
times the former magnetic energy. 
But, on the other hand, in experiment No. VII, the appli- 
cation of the compound process to a very long wire, was pro- 
ductive of very little advantage. Nor was the compound 
process of so evident an advantage in the third series of ex- 
periments : in this case, however, the failure of effect was 
probably occasioned by the very small size of the upper rod, 
I ii, in comparison of the magnitude and mass of the lower. 
2. Another object of enquiry in these investigations was 
the effect or relation of temper , in connection with the degree 
of magnetic energy developed. The result with the first 
apparatus, was conformable to the law of magnetics in ge- 
neral ; namely, that the softer the temper the more suscep- 
tible the steel becomes of the magnetic condition. By a 
comparison of experiments No. I. with II., V. with VI., and 
IX. with XII. and XIII., the advantage of softening the wire 
is very obvious. In the first instance, a steel wire in the state 
in which it was drawn could only be made to lift between 
36 and 73 grains ; but the same wire, on being softened, 
readily lifted 18 6 grains, after nine blows on the simple pro- 
cess, and after 80 blows by both processes, its lifting power 
was augmented to 326 grains, being nearly twice its own 
weight, and at least five times the power it acquired in its 
untempered state. But this difference of susceptibility for 
receiving the magnetic energy, is rendered still more obvious 
b y a comparison of the second set of experiments (No. V. 
and VI.) A long wire, untempered, being struck 20 or 30 
