29S Prof. Barlow’s Experiments for determining the 
Observations on the reciprqcal bearings of the Compasses 
marked B and C. 
Bearing of 
Fore-Compass, 
& Ship’s Head 
from After- 
Compass. 
B. 
Bearing of 
After-Compass 
from Fore- 
Compass. 
C. 
Diiference or 
Local Attrac- 
tion at Fore- 
Compass. 
Bearing of 
Fore-Compass, 
& Ship’s Head 
from After- 
Compass. 
B. 
Bearing of 
After-Compass 
from Fore- 
Compass. 
C. 
Difference or 
Local Attrac- 
tion at Fore- 
Compass. 
North. 
South. 
0° 0' 
South. 
N 14° 10' W 
S 16° 20' E. 
+ 2 10 
S 15° 40' E. 
N 16° 40' W. 
— 1° 0' 
31 10 
23 30 
+ 7 40 
30 10 
36 50 
— 6 40 
46 0 
38 0 
-j- 8 0 
53 0 
61 0 
— 80 
60 0 
50 20 
+ 9 40 
55 30 
63 40 
— 8 10 
75 30 
59 40 
+15 50 
70 10 
84 20 
—14 10 
West 
74 16 
+15 44 
N 85 0 E 
S 70 0 W. 
—15 0 
S 75° 40' W. 
89 30 
+14 50 
70 40 
57 30 
—13 10 
60 0 
N 72 10 E. 
+ 12 10 
55 0 
44 10 
—10 50 
44 10 
54 40 
+10 30 
35 30 
27 6 
— 8 24 
30 0 
36 44 
+ 6 44 
20 0 
14 30 
— 5 30 
15 0 
17 50 
+ 2 50 
10 30 
9 8 
— 0 22 
From these results, it appears that the local attraction at the 
fore-compass amounted, towards the east and west, to more than 
15°; and as it appears that the north end of the needle was 
drawn forwards, it follows that the action of the iron belbw^ viz. 
the boilers and engine, had in this place a greater effect than 
the chimneys. 
At the place selected for the standard-compass, the action of 
the iron below was exactly or nearly balanced by that of the 
chimneys, so as to leave the compass nearly correct in its bear- 
ing ; and it only remained to examine the effect of the two bo- 
dies upon the steering-compass. With this view,^ a similar set 
of observations to the last, were made upon the standard- 
compass, and the other azimuth set up in the place where the 
binnacle or steering-compass stood. These results are exhibited 
in the following table : 
