10 
Proceedings of the Royal Society of Edinburgh. [Sess. 
W x D° 7 for the various values of held decreasing from the cyclic extremes 
(%■ L )- 
The broken line curve of the middle diagram of hg. II. has not yet been 
referred to. It is derived from the same experimental data from which the 
second series of curves (within the dash line rectangle) of hg. I.a were 
plotted, by selecting from eight distinct series of experiments for various 
values of H the readings obtained upon the superposition of the initial 
single vibrational train only in each case. These readings are given fully in 
Table II. The intensity of the vibrations is represented by W x D° 7 = 0*38, 
and the necessity of taking readings at values of decreasing held close 
to the cyclic extreme, for this the lowest vibrational intensity used in these 
experiments, may be noted. 
Table II. — Decreasing Cyclic Field. Mechanical Vibrations. 
w 
c+H 
o | 
TJ1 
Vibrations super- 
posed upon 
. Vibrations regarded as 
superposed upon + H. 
oo 
CD O 
4 + 
> 
H + . 
H - . 
Average 
readings. 
x2-95 = 
change of B. 
CO 
6 
II 
© 
Q 
T9 
3*0 
-3*5 
3-25 
9-5 
X 
is 
1-86 
1-25 
-075 
DO 
3 
i—5 
i — i 
1*83 
0-25 
-0-25 
0-25 
0-75 
bb 
cpi 
1-72 
-0-5 
0-25 
- 0-375 
-1 
<D 
> 
P 
p 
o 
1-6 
- 1*0 
0-75 
-0-875 
-2-5 
o> 
£ 
1-34 
- 1*0 
1*0 
-DO 
- 3 
Pi 
CD 
o 
Pi 
pq 
0-52 
- 1-75 
1-75 
- 1*75 
-5 
0 
-2-75 
1-75 
-2-25 
-6-5 
Results . — When damped trains of mechanical vibrations of increasing 
intensity are superposed upon that part of a normal hysteresis loop when 
the held is decreasing, the induction is for various values of held neither 
at nor too far removed from the cyclic extremes, first decreased, afterwards 
increased. The curves representing these changes (hgs. I. and I.a) hrst fall 
somewhat below, afterwards may rise largely above, the horizontal axis. 
Any one of these curves is sufficient to show that the direction of the 
induction change is not independent of the vibrational intensity, while 
a comparison of the curves confirms the conclusion previously arrived at 
