168 
Lieut. Foster’s observations on the diurnal changes 
North end of Needle to the N E. 
The situation of the magnets, in this case, was the same as in the preceding observations at N. E ; 
except that their ends nearest to the needle were 29,7 inches from the centre of the compass-box: the 
needle making 1 vibration in 12 seconds, the directive force was reduced in the ratio of 0,22 to 1. 
Date. 
Mean 
Time of 
Obser- 
vation. 
A. M. 
or 
P. M. 
Reading of 
north end of 
Needle. 
Temp. 
Fahrenh 
Direction .of 
north end of 
needle during 
Time that a ho- 
rizontal needle 
took to make 
60 vibrations. 
Winds. 
Weather. 
Remarks, &c. 
Instr. 
westerly daily 
variation. 
1825 . 
h. 
m. 
0 
/ 
O 
m. s. 
Apr. qth 
I 
00 
A.M. 
N54 
00 E 
ZOi 
18 
4 
Easterly 
Hazy 
2 
00 
54 
00 
— 2°1 
17 
7>3 
moderate 
« 
3 
12 
53 
50 
— 2Q| 
18 
8,2 
3 
48 
53 
5° 
—21 
4 
8 
53 
3° 
—20 
18 
7,5 
5 
00 
53 
00 
—20 
...... 
18 
12 
6 
00 
5 2 
00 
20 
0 « • • • • 
18 
8 
6 
3° 
5i 
3° 
—20 
7 
00 
S 1 
00 
20 
18 
8,2 
7 
3° 
5° 
40 
—20 
18 
7,5 
9 
00 
5° 
20 
■ — 185 
18 
9»7 
9 
35 
44 
5° 
— i8j 
Ditto 
Overcast 
9 
5° 
44 
10 
— 18J 
. . T 3 . . 
18 
9,2 
10 
! 5 
44 
10 
—18 
JZ 
10 
45 
44 
00 
— I 7 l 
4 -» 
11 
10 
44 
00 
—17 
4 = 
• • wr • 
18 
16,1 
1 1 
45 
43 
40 
—17 
"u 
12 
8 
P. M. 
43 
00 
— 16J 
a > 
• *rC • • 
18 
9,7 
1 
5 
38 
55 
—16 
4 -> 
* * O * * 
17 
58,5 
Max. westerly var. 
1 
30 
38 
40 
—16 
h 
2 
10 
38 
3° 
—16 
l 7 
53,9 
2 
30 
38 
>5 
— *5 
3 
10 
38 
00 
— 16 
17 
00 
rC 
+ 3 
5° 
34 
00 
—16 
>7 
4^4 
5 
00 
34 
00 
—17 
17 
4M 
6 
00 
34 
00 
—17 
17 
55 
6 
30 
34 
00 
—17 
7 
00 
34 
00 
—17 
*7 
43 
8 
00 
34 
00 
—17 
17 
50,2 
9 
10 
34 
20 
—iH 
17 
47,2 
9 
45 
35 
20 
—19 
10 
5 
35 
30 
—19 
1 7 
54,4 
Easterly 
Hazy 
10 
35 
35 
50 
—19! 
moderate 
1 1 
7 
36 
00 
—19 

1 7 
55,4 
1 1 
34 
36 
3° 
“i9 
1 1 
5 6 
37 
3° 
—19 
f 7 
56,5 
