Gottingen 
‘ 
: 
18 
. 21 
. 25 
. 28 
20 
20 
21 
me 
' 
Mean Time, 
Commencement of 
i Observations. 
25 
40 
20 
15 
20 
OBSERVATIONS OF MAGNETIC Dip, Marcu 18—Juty 8. 1842. 
Dura- 
rea Thermo- 
Once meter. 
vation. 
m. io 
48-0 
45-0 
55-0 
45-0 
49-0 
44-0 
55-0 
42-0 
47-0 
62-0 
49-0 
65 61-4 
160 57-0 
100 47-2 
85 63-1 
55 55-0 
85 57-0 
60 55-0 
90 55-5 
120 69-0 
120 59°5 
90 65-6 
75 65-0 
100 61-0 
85 60-0 
105 65-5 
70 56:0 
85 67-3 
85 60-5 
120 61-7 
— 
See ee 
MEAN OF READINGS. 
71 
71 
71 32.37 25-87 
28-25 
23-87 
29-50 
21-87 
31-12 
25-87 
31-75 
30-25 
37-88 
32-88 
32-62 
33-12 14-00 
38-00 
33-88 
38°50 
36-00 
40-38 
38-50 
7-88 
12-50 
12-75 
12-37 
16-12 
15-00 
A. North 
Minus 
B. North. 
+ 9:37 
+ 9-00 
+ 20-25 
+ 17-88 
7-50 
1-25 
5-75 
5-00 
1-00 
5-25 
4-62 
+i +tt+ 
4-87 
0-25 
8-50 
6-50 
+ 19-12 
+30-12 
+ 21-38 
+ 25-75 
+ 23-63 
+ 24-26 
+ 23-50 
Observed 
71 
71 
Dip. 
29.12 
23-31 
20-56 
27-56 
23-37 
23-06 
20-37 
23-69 
22-87 
24.94. 
20-81 
24-37 
23-56 
63 
REMARKS. 
{This and the previous observations, with the 
1 exceptions noted, were made by Mr. Russell. 
{This and the following observations were 
\ made by me. J. A. B. 
It is possible that in some of the readings for 
this observation the divisions of the limb 
had been taken for 5‘ instead of 10’. 
oe the agate planes, care being taken 
4 that the glass door was shut, as in shutting it 
\ exerts a pressure on the bottom of the box. 
Although great care and much time was 
bestowed on this observation, it can hardly 
be considered good, very different readings 
: being obtained after repeatedly lifting the 
needle on the Y’s. 
Level of agate planes verified. 
fn this observation the needle was placed 
carefully on the agates, lifted by the Y’s, 
gently let down and allowed to vibrate 
through about 10°; then, when at rest, read. 
This observation made in the same way as last. 
Level of agates verified. 
The observations of June 3¢ were made in 
order to determine the effect, on the final 
result, of lifting the needle on the Y’s one, 
two, or three times. See Note below. 
While changing the poles the needle fell upon 
the carpet from a height of about two feet. 
This result obtained in the same way as the 
{ second result, June 34, 
Id. 
In some of the readings the needle had to be 
lifted frequently before a satisfactory obser- 
vation could be made, 
Allowing the needle to vibrate through 10° 
has not been found satisfactory. The needle 
is now checked near its supposed position of 
rest, and is lifted and lowered by the Y’s 
till satisfied that lifting does not alter the 
reading. 
Great care taken with this observation. 
June 34, The needle was checked so as to allow it, when lowered on the agates, to vibrate through 10°. After coming to rest the position 
. (yas read. The first result, June 34, was obtained from the readings made in this way. After each of the readings for the first result, the needle 
‘| Was lifted by the Y’s and lowered gently (the arc of vibration being small) and again read ;—these readings give the second result. The needle 
being lifted, &., as in the second case, a third result was obtained. 
