horizontal needle when under the influence of magnets. 387 
cold water on the pans to reduce the temperature ; and 
had at 
Time. 
Points of Equilibrium. 
Remarks. 
h. m. 
11 0 
no point. 
N. E. 
0 / 
7 20 
.no point. 
f I now uncovered the 
[ magnets. 
11 15 
no point. 
1 45 
no point. 
11 30 
no point. 
0 40 
no point. 
The needle now appeared to have scarcely any directive 
power, since, when agitated again, it moved to N i° 15' W, 
and at n h 45 m , on being agitated, it settled at N 2 0 15' W. 
At this time I covered the magnets with blotting paper, to 
retain the water, and poured on them, for some minutes, 
water at the temperature 55 0 , after which I had at 
h. m. 
N. W. 
O / 
N. E. 
0 / 
S. W. 
0 / 
11 52 
M 
00 
0 
0 
14 40 
0 
0 
0 55 
14 55 
9 20 
O 20 
1 12 
10 20 
When the needle 
removed the paper 
from the magnets. 
covered the magnets with paper, and poured water nearly 
boiling on them ; when the needle went rapidly to o°, then 
returned and stood steadily at N i° 20' W. I again reduced 
the temperature by pouring water at 55 0 on the magnets, 
and had, at 
h. m. 
N. W. 
W. E. 
s. w. 
1 25 
17 10 
14 10 
0 10 
The need 
e pointing 
14 10 
I again 
o ' 1 j — w J ^ 7 ' 
continually agitated, stood at N o° 40' W, but a few minutes 
