44 Mr. Christie on the effects of temperature 07 i 
Table of observations made within doors, S^c. 
Date and time of 
observation. 
Tempera- 
ture of the 
Magnets. 
Point 
Westerly. 
s of Equilibr 
Easterly. 
ium. 
South. 
Barometer. 
Therm. 
attached. 
h. 
m. 
0 
0 / 
0 / 
0 
04 E 
0 ' 
0 
to 
6 
lO 
62.00 
81 50 
80 12 
0 
30.27 
63.00 
c 
7 
3 ° 
62.50 
81 56 
80 26 
0 
08 E 
30.28 
62.00 
u 
• O 
9 
oo 
63.00 
82 56 
81 18 
0 
06 E 
30.28 
64.50 
N S 
10 
3 ° 
63.40 
82 32 
80 40 
0 
16 W 
30-27 
65-75 
00 
o 
oo 
63.66 
81 32 
79 34 
0 
24 W 
30.28 
66.00 
1 
3 ° 
63-75 
81 04 
79 02 
0 
32 W 
30.28 
66.33 
^ . 
5 6 
3 
oo 
64.20 
80 10 
78 38 
0 
30 W 
30.28 
66.33 
^ o 
4 
3 ° 
65.00 
80 10 
78 36 
0 
20 w 
30.28 
67.75 
C/5 
5 
55 
65.00 
79 40 
78 24 
0 
16 w 
30-27 
65.66 
m Sj 
7 
30 
64.66 
79 44 
78 20 
0 
16 w 
30.27 
63-50 
< 
9 
25 
63-33 
79 54 
78 50 
0 
16 w 
30.26 
61 .66 
1 1 
30 
63.00 
80 28 
79 00 
0 
I6W 
30.26 
64.00 
In all the observations v^^hich I have made, I have consi- 
dered the magnetic meridian to be the line of direction of a 
needle at the time when that direction is most stationary, 
that is at about seven o'clock in the evening ; and in arranging 
the magnets for the foregoing and similar observations, I 
have not only always found much difficulty, but have seldom 
succeeded, in determining so accurately the axes of the 
magnets, and adjusting them so precisely in the meridian, 
that, at that time, the needle should be held in equilibrio 
exactly at south, and also at points towards the west and 
east equidistant from the north, which evidently ought to be 
the case with a perfect adjustment. Partly from this dif- 
ficulty in adjusting the magnets, of which those who have 
attempted similar arrangements will be best aware, and 
partly from the changes which, even during the evening, 
take place in the direction and intensity of the terrestrial 
forces, the east and west points of equilibrium, in the fore- 
going observations, are not, during the evening, at equal 
