in the position of the horizontal needle , &c, 
167 
North end of Needle to the NE. 
The magnets were now placed to the north and south of the needle, with their axes slightly inclined to 
the magnetic meridian ; the north magnet had its north pole towards the compass-box, at the distance 
of 29,1 inches from its centre, and the south magnet had its south pole towards the compass-box, at 
the distance of 30,1 inches from its centre: the time in which the needle now performed 1 vibration, 
was 14,4 seconds ; so that the directive force was reduced in the ratio of 0,15 to 1. 
Date. 
Mean 
Time of 
Obser- 
vation, 
A. M. 
or 
P. M. 
Reading of 
north end ol 
Needle. 
Temp. 
Fahren 1 . 
Direction of 
north end of 
needle during 
westerly daily 
variation. 
Time that a ho- 
rizontal needle 
took to make 
60 vibrations 
Winds. 
Instr. 
1825. 
h. m. 
° / 
0 
m. s. 
April 8 th 
5 10 
A. M. 
N45 30 E 
—23 
....... . 
18 1,3 
East 
5 55 
45 20 
— 22 
Fresh 
6 30 
45 20 
—22 
18 9,2 
6 55 
45 20 
— 22 
7 20 
45 20 
— 2l| 
18 12,3 
7 5° 
44 10 
21 g 
8 00 
43 5° 
—2l! 

18 3,4 
9 26 
42 20 
20 
....... 
17 58,8 
9 28 
42 00 
20 
• • . . 
18 22,8 
10 10 
41 50 
20 
G 
xo 30 
4i 30 
—20 
rG 
•*-» 
11 10 
41 10 
— 19 
pG 
• • bO • • 
18 6 
11 30 
41 00 
— 18 h 
TT 
Noon 
36 10 
— I8J 
0) 
• • *es • • 
*7 5»>8 
0 15 
P. M. 
35 00 
-i 8| 
4-» 
0 30 
29 00 
-18 k 
+ 1 10 
1 30 
— 17 
17 C6,2 
2 00 
10 10 
—17 
«7 5°>5 
2 50 
16 30 
—17 
3 10 
17 00 
—17 
• ••«••• 
*7 44 
Ditto ( 
3 47 
17 40 
—17 
17 53 
moderate 
5 5 
2 5 3o 
—17 
l 7 43>5 
5 3o 
2 5 3o 
—17 
6 00 
27 30 
—17 
17 37 
6 20 
27 30 
—18 
6 35 
32 00 
—19 
7 10 
33 3° 
—19 
17 4M 
8 00 
37 00 
—19 
17 34.7 
9 3° 
40 00 
— 20 
17 44,6 
10 00 
40 00 
—20 
17 45 >4 
10 35 
40 00 
• — 20 
11 12 
45 10 
— 20I 
Easterly 
— Midn 1 
5i 3° 
— 20I 
Light . 
Weather. 
Clear and 
Fine 
Fine 
Remarks, & c. 
It will be seen that, 
at the time of the 
greatest westerly var, 
an increase of direct- 
ive power in the ho- 
rizontal needle took 
place, which accounts 
for the great expres- 
sion of 50° for the 
daily variation. 
Max. west. var. 
Hazy 
Max. east. var. 
