374 
Mr. Barlow on the effects produced in the rates of 
TABLE IV. 
Experiments and observations on the rates of Chronometers in the vicinity of iron bodies , at the Observe/ 
of the Rev. Mr. Evans, JEoolwich Common. Lat. 51° 29' 8" North, long. 4' 10' ; East. 
No. IV. Box Chronometer in Glass Case, by Pennington. Detached rate + l" "5. 
1 
Days. 
Ther- 
mome- 
ter. 
Clock 
Rate. 
Chronometer 
+ or — at 
Noon. 
Daily Rate 
of Chrono- 
meter. 
Mean Rate 
in each 
Position. 
Gain or Loss 
per day in 
each po. 
sition. 
Time of ten 
Compass 
Vibrations. 
Proportional 
Magnetic 
Intensity. 
Position of Chronometer, Remarks, &c. 
March 24 
25 
26 
27 
28 
29 
30 
O 
47 
48 
47 
49 
48 
50 
48 
—1-4 
—2-4 
—24 
/ // 
— 0 25 5 
— 0 24 7 
— 0 26 0 
— 0 26-4 
— 0 26 8 
— O 28 6 
// 
+ 0-8 
— 13 
—04 
—0 4 
—09 
—09 
>—0 5 
—20 
29-0 
126 < 
_ 
Placed the Chronometer to the South 0 . 
ball; height from the floor 1P4 inchesa 
tance from the vertical passing through 
centre of the ball 17 - 3 inches, correspoi 
to lat. 35°16' S, long. 90°, and centra; 
tance 18 inches. 12 o’clock. South. 
31 
April 1 
2 
3 
49 
48 
51 
50 
—2-5 
—1-7 
—0 27 0 
—0 25 5 
— 0 22 6 
—0 20 3 
+ T 6 
+ 15 
+ 29 
+ 2-3 
> + 2-1 
J 
325 
100 | 
<. 
Detached from the ball in order to obtaiit 
natural rate. 
4 
49 
—19 
— 0 20 8 
—05 
I 
I 
Placed to N. of ball; height 10*5 inches; dis n 
5 
49 
—25 
— 0 20 - 9 
—0 1 
[ —0 3 
— 1-8 
33 5 
94 4 
from vertical 1 13 inches; or lat. 0°; long 
6 
47 
—0 211 
— 0-2 
J r 
1 
central distance 12 inches. 12 o’clock, S 
7 
50 
— n ong 
+ 0 3 
•j 
r 
8 
— 1-9 
—0 196 
+ 1-2 
l 4-0-3 
— 1-2 
335 
94 - 
Same situation. 12 o’clock, West. 
9 
57 
— T9 
—0 20 3 
—0-7 
J 
l 
10 
58 
—1-7 
—0 195 
4 - 0-8 
1 
11 
57 
—0 192 
+ 03 
4-0-8 
—0-7 
335 
94 ^ 
Same situation. 12 o’clock, East. 
12 
55 
—1-7 
— 0 18-0 
4 - 1-2 
J 
13 
53 
—20 
— 0 16 6 
4-1-4 
1 
r 
14 
52 

— 0 16 1 
4-0-5 
15 
50 
—0 156 
4-05 
> 4 * 0-6 
—0-9 
335 
94 4 
Same situation. 12 o’clock, North. | 
16 
49 
—0 157 
—0 1 
I 
17 
49 
— T9 
—0 15 1 
4-0 6 
J 
1 
18 
51 
— 2*1 
—0 149 
4 - 0-2 
] 
r 
19 
53 
* 1 c t • • 
—0 144 
4-0-5 
! 
Same situation, but with the 12 o’clock. Si 
20 
55 

—0 150 
— 0-6 
> —0 6 
—2 1 
335 
94 
as on the 4 th, 5th, and 6 th. 
21 
57 
—0 164 
— 1-4 
1 
1* 
22 
56 
—2-4 
—0 179 
— 1-5 
j 
L 
f 
Placed this Chronometer on pedestal, n 
23 
56 
—2-4 
—0 18-1 
—02 
1 
* 
of the plate ; distance from vertical th u 
24 
60 
— 1-5 
— o 17-7 
4-0-4 
> 4-02 
I 
— 1-3 
the centre of plate 10 inches ; height c 
25 
63 
—0 172 
4-0-5 
centre 10 inches. 12 o’clock. South. ■ 
J 
l 
Description of plate, page 365. 
26 
65 
—0-8 
—0 148 
4-2 4 
r 
27 
63 
—03 
—0 135 
4-1-3 
| 
1 
The Chronometer was detached daring a 
28 
62 
— 05 
— 0 12‘4 
4- 1 - 1 
> 4-1-3 
1 
32'5 
100 < 
days, to ascertain whether it would ret n 
29 
60 
—09 
—0 11 6 
4-0 8 
! 
its former detached rate. 
30 
56‘ 

—0 10-9 
4-0-7 
J 
L 
— 
* Not taken for the reason assigned in page 3/6. 
