developement of magnetical properties in steel and iron , &c. 205 
b. Compound process. 
After 12 smart blows, under this process, the lifting power 
was augmented to 186 grains. 
SECOND SERIES, 
for ascertaining more exactly the comparative effects of a difference 
of temper on wires of the same quality and dimensions , and of 
the relative advantages of the different processes for the deve- 
lopement of magnetism by percussion in equal wires. 
The apparatus consisted of the three iron rods ( I i, I ii, and I Hi,) 
with five new wires , from the same piece, of equal sizes, each 
of them being five inches in length, and 145 grains in weight ; 
namely, S u iv, S t\v, S t v, S t vi, and S t vii. 
Experiment No. IX. 
New steel wire, S u iv ( untempered ) ; not in the least degree 
magnetic. 
a. Simple process. 
5 smart blows struck on this wire whilst held on bar I i, 
( which bar had previously been struck 20 hard blows 
with the large hammer, through the medium of the bar 
Iiii) occasioned a lifting power of 37 grains. 
b. Compound process. 
[Magnetism of the wire destroyed. ] 
5 smart blows on this process, (each of the bars I i and I ii 
having been previously hammered whilst held vertically 
in the hand) produced a lifting power of 37 -}- 18 = 55 
grains, and very nearly 73 grains. 
