repetition of Mr. Christie’s experiments > &c. 195 
I. 
Table of the changes in the zero, or reading of the north end 
of the needle, and of the deviations due to the rotation of 
a circular iron plate (18 inches in diameter), its plane being 
in the plane of the secondary to the equator and meridian, ' 
and its centre in latitude o°, longitude 180°, at the distance 
of 16,5 inches from the centre of the needle. 
u 
« a s 
0 "o 0 js 
a | -g =» 
1 • 
0 0 g 
a»s-| 
Readings of north end of 
J 
Deviation of north end ofl 
3 
O 
g* . 
5.0 |a 
*0 0 
needle after plate had re- 
needle due to rotation of] 
a 
•- 0 
a g 
go 
S.| 
- y 5 d 
g 0 -d v 
a> ir . 
<s _ £ 
«■§ g 
u « <2 
volved, its upper edge. 
plate, its upper edge. 
Remarks. 
|l 
H 
Point! 
brough 
with fi: 
pin,bel 
rotatior 
Zero, 0 
north 
die be; 
From East to 
West. 
From West to 
East. 
From East to 
West. 
From West to 
East. 
."s 
V 
o 
•2 *0 
0 .ts 
0 
O 
O / 
O / 
O * 
0 a 
O i 
0 
B 
+ 14 
60 
I 20W 
10 20 E 
3 00W 
n 40 E 
1 40W 
‘3 
20") 
120 
12 40 E 
20 20 E 
6 40 E 
7 40 E 
6 00 W 
‘3 
40 
180 
i 00 E 
12 IO E 
0 30W 
11 10 E 
1 30W 
12 
40 
Z40 
3 3 oW 
I 45 E 
11 55W 
S ‘5 E 
8 25W 
‘3 40 
300 
13 15W 
3 15W 
15 35W 
10 00 E 
2 20W 
12 
20 
3 gentle 
turns. 
O 
0 50W 
4 00 E 
9 30W 
4 5 ° E 
8 40W 
*3 
30 1 
+13 
60 
3 10W 
10 00 E 
3 50W 
13 10 E 
0 40W 
‘3 
5 ° 
120 
12 20 E 
21 30 E 
7 4 ° E 
9 10 E 
4 40W 
‘3 
5 ° 
l8o 
4 30 E 
15 00 E 
1 30 E 
10 30 E 
3 00W 
‘3 
30 
Z40 
5 10W 
1 20 E 
11 3 ?W 
6 30 E 
6 25W 
12 
55 
300 
1 7 40W 
5 20W 
19 20W 
12 20 E 
1 40W 
‘4 
00 
+ 13 
O 
2 10W 
3 5 ° E 
10 00W 
6 00 E 
7 50W 
‘3 
5°J 
+ ‘ 3«3 
Means 
1 23W 
7 3^^j E 
5 47 r f *W 
9 ‘-nr E 
4 2 4^W 
‘3 
2 5^ft 
300 
6 40W 
5 00W 
17 45 W 
1 40 E 
11 5W 
12 
4S 1 
240 
2 50 E 
3 40 E 
9 30W 
0 50 E 
12 20W 
‘3 
10 
180 
‘3 3 ° E 
15 20 E 
1 3° E 
1 50 E 
12 00 W 
‘3 
5 ° 
120 
14 55 E 
‘9 35 E 
5 2 5 E 
4 40 E 
9 30W 
‘4 
10 
60 
9 45 E 
9 45 E 
3 20W 
0 00 
13 5W 
‘3 
5 
+ ‘4 
0 
3 10W 
3 5 ° E 
9 10W 
7 00 E 
6 oW 
‘3 
0 
0 f 
3 gentle 
300 
4 40 W 
3 40W 
1 6 40 W 
1 00 E 
12 oW 
‘3 
turns. 
240 
3 3°E 
3 ‘5 E 
11 15W 
0 15W 
14 45W 
‘4 
3 ° 
180 
10 50 E 
13 00 E 
0 20 E 
2 10 E 
10 30W 
12 
40 j 
120 
13 15 E 
18 15 E 
4 15 E 
5 00 E 
9 00W 
14 00 
60 
z 00 E 
g 00 E 
3 10W 
7 00 E 
5 10W 
12 
10 
+ ‘4 
0 
5 45 W 
4 50 E 
7 20W 
10 35 E 
1 35 W 
12 
1C E 
+ l 4 
Means 
4 “t%E 
7 39tV e 
5 33tVW 
3 2 7t2- E 
9 45 w 
‘3 
I2-£ 
r 
