the intensity of magnetic forces , &c. 41 
atmospheric changes may influence the direction and intensity 
of the terrestrial magnetism ; I consider, therefore, in order 
that all possible information should be derived from a series 
of such observations as I am about to describe, that they 
should be accompanied with very precise observations of all 
the atmospheric changes which take place, particularly those 
of an electric nature. It was not always in my power to note 
these with the requisite precision ; and as the observations 
were not continued for a sufficient length of time to enable 
me to derive any thing from those which I made on the force 
and direction of the wind, the character and appearance of the 
clouds, &c. 1 omit them : I have however inserted the changes 
which I noticed in the state of the barometer. 
Table of observations, made within doors, on the Diurnal Changes 
in the positions of the Points of Equilibrium at tchich a Magnetic 
Needle teas retained by the joint action of Terrestrial Magnetism 
and of two bar Magnets, having their axes horizontal and in the 
magnetic meridian, and their centres at the distance 21.21 inches 
from the centre of the Needle. 
Date and Time of 
Temp. 
Points of Equilibrium. 
Barometer. 
Therm, 
Observation. 
of the 
Magnets. 
Westerly. 
Easterly. 
South. 
attached. 
eb 
h. m. 
6 00 
59*75 
0 
82 06 
0 / 
80 24 
0 / 
0 04W 
29.75 
0 
59.66 
B 
• ^ 
7 30 
60.00 
82 44 
81 06 
0 02 W 
29.75 
50.66 
rn 0 
8 55 
60.75 
82 20 
81 06 
0 06W 
29.74 
60.00 
s . 
10 30 
60.75 
82 34 
81 30 
0 14W 
29.75 
60.50 
0 00 
61.00 
82 04 
80 00 
0 44'W’ 
29.75 
60.50 
I 45 
61 . 15 
81 38 
79 ^6 
0 34W 
29.76 
59*75 
^ 1 
3 05 
60.75 
81 20 
80 20 
0 loW 
29.76 
60.00 
-q B 
4 35 
60.50 
81 34 
80 40 
0 06E 
29.75 
60.25 
N O. 
6 10 
60.00 
81 20 
80 46 
0 04E 
29.80 
57*75 
< 
7 40 
59.50 
8i 50 
80 52 
0 02 W 
29.82 
58.00 
9 30 
58*;5 
82 04 
80 32 
0 10 W 
29.86 
58.50 
MDCCCXXV. 
G 
