the intensity of magnetic forces , &c. 
13 
Table of the positions of the Points of Equilihrium, corresponding 
to different Temperatures of the Magnets retaining a Magnetic 
Needle in equilihrio. 6th June, 1823. 
Time of 
commencing 
observation. 
Temperature 
of 
N. Magnet. 
Points of Equilibrium. 
Temperature 
of 
S. Magnet. 
Time of 
concluding 
observation. 
Mean tempe- 
rature of the 
Magnets. 
N uri 
N 
d d 
rnso 
-a 
(U 
West. 
East. 
South. 
h, m. 
0 
0 / 
0 / 
0 
I2W 
0 
h. m. 
0 
u 
7 54 
62.0 
82 44 
82 30 
0 
62. 1 
8 01 
62.05 
8 lo 
59-3 
86 00 
84 50 
0 
12 
58.8 
8 17 
59.05 
c S 
8 3 * 
79.0 
74 40 
74 56 
0 
I 2 
76.3 
8 35 
77.65 
1 1 
8 40 
75.0 
76 02 
75 54 
0 
12 
73*0 
8 44 
74.00 
£ 
8 52 
71 .0 
77 30 
77 24 
0 
10 
70-3 
8 56 
70.65 
m r-< 
9 ” 
67*3 
79 ^6 
78 52 
0 
*4 
67.0 
9 16 
67.15 
B 
9 34 
63.8 
80 42 
80 50 
0 
18 
63.8 
9 40 
63.80 
9 S 3 
62.0 
81 50 
82 16 
0 
16 
62. 1 
lo 00 
62.05 
0 
Taking half the sum of the easterly and westerly arcs for 
the value of and substituting them successively for (p in the 
equation (<x), I obtain the values of corresponding to the 
respective mean temperatures of the magnets. These I have 
arranged in the following table ; placing in the second 
column the differences of the successive temperatures, and in 
■jn« 
the fifth the corresponding differences in the values of ^ ; 
these, divided by the numbers in the second column, will 
give the variation of the value of corresponding to a 
change in the temperature of the magnets of i® on Fahren- 
heit's scale : these variations in the values of ^ are contained 
in the last column of the table, and are denoted by A . 
