developement of magnetical properties in steel and iron, &c. 201 
These nails were of the following- weights in grains : — 
i£, 4 , 5 i, 7 i, 18, 37 , 73 , 88, 112., 18 6 , 2 46,. 326, 389, and 
482. 
In trials of the lifting power of the steel wires, in the sub- 
sequent experiments, the weight of the largest nail that 
could be lifted is set down.* In some instances a small 
weight was added to the nail, when the difference between 
this and the next in the series was considerable ; in this case, 
the lifting power is stated at the weight of the nail, plus the 
number of grains of the appended weight. 
FIRST SERIES, 
for determining the superiority of the Compound process over the 
Simple process, when employed for the developement of mag- 
netism in steel wires by percussion ; and for the trial of the 
general effect of Temper on the magnetic attraction elicited . 
The apparatus consisted of the iron rods I i, Iii, and I iii, together 
with various steel wires. 
Experiment No. I. 
DMy >■] 
Steel wire Su i, [ namely , steel wire untemperedf\. Length, 5 
inches ; diameter , \th of an inch ; weight, 167 grains. 
This wire was hammered, for a length of time, on the 
simple process, and only lifted 36 grains. 
* I am perfectly aware that the lifting power of a magnet is by no means a cer- 
tain measure of its magnetic force, and that the comparative lifting powers of 
magnets of various sizes do not afford an exact measure of their relative degrees 
of magnetic energy ; but this mode of trial was employed both on account of the 
impossibility of making accurate observations on magnetic intensities at sea, where 
MDCCCXXIV. D d 
