838) 
XXXVI. Electromagnets—II1. Lron and Steel. New Theory 
of Magnetism. By R. OH. M. Bosanquet, St. John’s College, 
Oxford. 
To the Editors of the Philosophical Magazine and Journal. 
GENTLEMEN, 
N the February number of the Philosophical Magazine 
(p. 73) I gave a number of experiments on the Perme- 
ability (w) of Iron and Steel, with empirical formule founded 
on Fourier’s Series. I also gave the elements of a new theory 
leading to equations of the form 
p=A(G, —B) cos 8, 
o= 0, 
k 60°—o0 
Bias Simignen | 
and gave the comparison of this theory with experiment in 
the cases of Crown (soft bar) Iron ring H, and Steel ring J 
(first soft state). I propose now to communicate the com- 
parisons of all the remaining experiments of the former paper, 
and of three additional sets on J. 
For clearness I will recapitulate shortly the bearing of the 
formule. 
Hach molecule has one, and only one, axis of transmission 
(like* a bead with a hole in it). The axis is capable of trans- 
mitting %, lines of force and no more, and the molecular 
permeability is proportional to %3%,,—%, or to the defect of 
saturation. (lf we pack the hole in the bead with thin wires, 
the aperture remaining is represented by the number of wires 
that remain to be got in.) 
A is the molecular permeability per unit defect of satu- 
ration. 
6 is an auxiliary angle representing the obliquity of a 
zigzag which would augment the resistance to the amount 
actually observed. 
@ is the average inclination of the axes of the molecules to 
the direction of magnetization ; initially it is always 60°. 
w is the unit angle. 
f is the factor connecting @ and 6. 
— represents the force of molecular torsion which is in equi- 
librium with the tendency of the lines of force further to 
deflect the average molecule. 
_ * These statements are not to be taken as actual hypotheses, but as 
geometrical analogies of the distribution. 
Phil. Mag. 8. 5. Vol. 19. No. 120. May 1885. 2A 
