278 
COMMANDER JOHNSON’S MAGNETIC EXPERIMENTS 
Table VII, 
Vertical Vibrations for Intensity observed at Tarbert Island and on board the Garry- 
owen. 
At position A on board, Nov. 
2. — Barom. 29-9, Therm. 52°. 
Poles of needle direct. 
Vessel’s head north. 
Vessel’s head south. 
Reading of 
needle. 
Arc. 
Time. 
Reading of 
needle. 
Arc. 
Time. 
Lower 
end. 
Upper 
end. 
Lower 
end. 
Upper 
end. 
o / 
78 45 
o / 
78 30 
23J 
h m s 
4 42 7-5 
o / 
73 30 
o / 
Do. 
o 
24 
h m s 
2 52 7-5 
28 
to 
■ ... - 
26 
49-5 
74 30 
Do. 
47-5 
11 
9 
30-5 
... 
29-5 
52 
14 
51-5 
13 
... 
12-5 
33-5 
34 
h 
50-5 
55 
11 
16 
h 
4 45 31-5 
8 
2 55 37-5 
Time of 100 vibrations 3 m 24 s . 
Time of 100 vibrations 3 m 30 s . 
At position A on board, Nov. 6. — Barom. 29-9, Therm. 48°. 
73 50 
Do. 
24 
3 7 3-5 
to 
22-5 
74 0 
Do. 
44 
5 
26-5 
48-5 
10 
30-5 
52 
13 

8 
3 10 34 
Time of 100 vibrations 3 m 30 s, 5. 
o £ 
■5 p 
At Tarbert Island, Nov 19.- 
Barom. 30, Therm. 52°. 
Poles of needle direct. 
Reading of 
needle. 
Lower Upper 
end. end. 
o / 
71 25 
71 0 
o / 
71 25 
71 10 
Arc. 
244 
Time. 
h m s 
12 52 1 
24 
49-5 
14-5 
38-5 
4 
29 
54 
19 
43-5 
12 56 8 
Time of 100 vibrations 4 m 7 s . 
At position I on board, Nov. 13.- 
Barom. 30-5, Therm. 46°. 
Poles of needle direct. 
CO 
£ tio 
o c 
% 'o 
0-2 
Si s 
Vessel’s head south. 
Reading of 
needle. 
Arc. 
Time. 
Lower 
end. 
Upper 
end. 
o t 
o / 
h m s 
74 0 
74 50 
24 
2 46 57 
to 
17-5 
74 30 
40 
4 
26 
49 
11-5 
34 
57 
20 
7 
2 50 42-5 
Time of 100 vibrations 3 m 45 s, 5 
a 
o ? 
o n 
C w 
s*. .£ 
o 
o 
70 25 
70 25 
23J 
C/5 
W 
6 
12 8 57-5 
20-5 
45-5 
10 
35-5 
0-5 
25-5 
51 
15-5 
40 
12 13 5 
Time of 100 vibrations 4 m 7 S ‘5. 
74 15 
74 20 
24 
3 17 58 
18-5 
41-5 
4-5 
27 
50-5 
13-5 
36 
59 
22 
5| 3 21 44-5 
Time of 100 vibrations 3 m 46 s, 5 
Moderate breezes from the west, 
cloudy weather. 
Dark 
Calm and cloudy. 
Calm and cloudy. 
