[ *97 ] 
IX. Experiments and observations on the developement of mag- 
netical 'properties in steel and iron by percussion : — Part II. 
By William Scoresby, Jun. F.R.S.E. &c. Communi- 
cated by Sir Humphry Davy, Bart. Pres. R. S. 
t 
Read January 29, 1824. 
Hav.n g had the honour of laying before the Royal Society 
a Paper on the “ Developement of Magnetical Properties in 
Steel and Iron by percussion,”* I beg permission to add to 
that Communication an account of other experiments ; in 
which much higher degrees of magnetic energy were ob- 
tained by percussion, in the employment of new combinations 
of rods of iron not previously magnetic. 
It was shown in the former paper, that the extraordinary 
developement of magnetism, by this process, arose from the 
use of a large bar of iron, or soft steel, first rendered mag- 
netic by hammering, in the position of the dipping needle, 
or in the direction of the magnetic force ; for, on applying a 
similar quantity of percussion to the same bar whilst held 
on a mass of brass or stone, or even on a bar of iron laid in 
the plane of the magnetic equator, the polarity elicited did 
not exceed the twenty-ninth part of that obtained by the use 
of the vertical rod of iron. 
In the subsequent experiments I had two principal objects 
* Philosophical Transactions for 1822, p. 241. 
