horizontal needle when under the influence of magnets. 349 
so that the needle made ten vibrations in one-hundred seconds, 
and consequently the directive force was still farther reduced ; 
its ratio to the whole undiminished force being now .068 to 1. 
With this adjustment I observed very carefully the direction 
of the needle, nearly every hour, except during the night, 
from the evening of the 5th of April, till that of the 12th of 
April. On the 5th of April, 9 h 50® P. M. the needle pointed 
N o° 04,' W, and at 1 i h 45® it pointed N o° io' E, but as it ap- 
peared afterwards to be most stationary in the evening at about 
N o° 20' E, that point is assumed as zero in the following table. 
Table of the Diurnal Deviations of a Magnetic Needle whose direc- 
tive force ivas diminished in the ratio oflto . 068 , by the action 
of two bar Magnets placed in the line of the Dip , the N. end of 
the Needle pointing North. 
April 
h. 
m. 
6 
00 
6 
30 
7 
00 
7 
3 ° 
8 
00 
8 
3 ° 
9 
00 
10 
00 
1 1 
00 
Noon. 
0 
3 ° 
1 
00 
1 
3 ° 
2 
00 
2 
3 ° 
3 
00 
4 
00 
5 
00 
6 
00 
7 
00 
8 
00 
9 
00 
10 
00 
11 
00 
6 
0 
/ 
1 
00 
— 1 
00 
— 1 
20 
• — 1 
38 
— 1 
24 
— 1 
16 
— 0 
28 
+ ° 
28 
+ 1 
26 
+ 1 
46 
+ 1 
40 
+ 1 
40 
+ 1 
26 
+ 1 
08 
+ 0 
18 
+ 0 
02 
— 0 
04 
0 
00 
0 
00 
O / 
■ o 24 
■ o ^8 
16 
00 
— o 
— o 
+ 1 
+ 2 
+ 2 
+ 2 
+ 2 
+ 2 
-f 1 16 
+ 0 52 
+ ° 
+ o 
o 
— o 
+ O 
+ O 
+ O 
U h 'S m \ 
\o OO I 
■O 36 
— o 
+ ° 
+ 1 
+ 2 
+ 2 
+ 2 
+ 2 
+ 2 
+ 2 
+ I 
+ I 
+ ° 
+ o 
+ ° 
o 
24 
3 2 
40 
5 ° 
5 ° 
50 
44 
18 
10 
3 6 
H 
44 
34 
16 
00 
4 ° °4 
— 010 
— o 06 
O 14 
O OO 
— c 10 
+ 016 
+ 1 54 
+ 2 30 
+ 2 32 
+ 2 24 
+ 1 06 
— o 04 
— o 04 
+ 0 12 
— o 06 
•o 58 
■O 16 
IO 
( 5 h ' 5 m ) 
\— o 22 / 
■ 1 02 
— 1 16 
— 1 06 
+ 1 06 
+ 2 04 
+ 2 10 
+ 1 48 
+ O 
+ O 
+ O 
+ O 
+ O 
5 6 
42 
28 
34 
40 
+ o 28 
o 00 
11 
— o 24 
— o 08 
+ 1 °4 
4 1 c6 
+ 1 4 ° 
+ 2 40 
+ 4 00 
+ 4 20 
+ 4 *4 
+ 3 °8 
4 z 04 
+ 1 3 ° 
+ ° 54 
4 o 20 
+ 038 
(— 1 40)! 
— o 06 
12 
+ O 
— o 
— o 
— o 
— o 
+ O 
+ O 
+ 2 48 
+ 3 3 6 
4 3 5 6 
+ 3 28 
4 2 04 
+ 016 
+ 0 24 
4 o 26 
+ 0 14 
Means. 
35 
28 
43 
44 
57 
18 
+ o 21 
+ 1 20 
4 2 26 
+ 218 
+ 2 49 
+ 2 32 
+ 2 41 
4- 2 2 4 
+ 1 
+ 1 
+ o 42 
+ o 26 
+ O 20 
+ 0 12 
+ o 15 
— o 03 
— o 04 
26 
13 
