13
143
30. The observations of magnetic declination and horizontal force were made with the unifilar ,magnetometer, ELLIOTT BROS. No. 55, and the dips were observed with dip circle, DOVER No. 71. The methods adopted are explained in Appendix G. of Observations and Researches made in 1885. The value of logK was 3.44975 at 27° cent. and the value of P was + 6.608. The mean value of the magnetic moment of the vibrating needle was 0.48203 in British Units and 629.32 in C.G.S. Units.
The times of vibration exhibited in the table are each derived from 12 observations of the time occupied by the magnet in making 100 vibrations, corrections having been applied for rate of chrono- meter and arc of vibration. The observations of horizontal force are expressed in C.G.S. Units, but the monthly synopsis exhibits X, the horizontal as well as Y, the vertical, and the total forces, which have been computed by aid of the observed dips, and their values are also given in British Units and in Gauss's Units. The declination and dip are decreasing, while the horizontal force is increasing as well as the total force. Observations made before the Observatory was founded show that the dip was increasing during the forty years previous.
OBSERVATIONS OF MAGNETIC DECLINATION AND DIP.
1888.
H.K.M.T.
Declination, East.
Observer.
H.K.M.T.
Dip, North.
Needle. Observer.
January,
February,.
March,
April,
May,
July,
August,
September,
16d. 2h. 38 p.
14 2 31
14 2
40 P.
16 2 36 p.
15 2 33 p.
17 2 36 p.
14 2 28 p.
14 2 38 p.
P.
October,
November,
15
2 28 p.
14 2 45 p.
0° 43′ 21′′
0′ 43 56
0 43 3
0 39 49
0 39 38
0 38 9
0 39 54
0 40 11
0 42 4
F.G.F.
"
17. 3. 33 p.
15 3 2 p.
32° 22' .89 24 .53 21 .02
No. 1
F.G.F.
2
»
1
"
21 .40
M.A.
15 3 30 p.
19 .56
M.A.
20.03
2
**
""
14 3 28 p.
21 .34
1
"
20.06
2
F.G.F.
M.A.
17 3 23 p.
23 .12
1
F.G.F.
22 .33
18 3 23 p.
19 .37
1
M.A.
16 .78
""
39
15 3 27 p.
18.11
1
"
13 .31
2
"
"
15 3 2 p.
20 .18
1
"
20.88
2
0 43 13
F.G.F.
M.A.
16 3 37 p.
22 .51
19 .30
16 3 29 p.
26 .75
F.G.F.
M.A.
30.21
17
3 22 p.
26 .00
F.G.F.
22 .32
December,
14 2 47 p.
0 39 40
F.G.F.
15 3 10 p.
22..39
W.D. M.A.
18 .59
39
16 3 28 p.
22 ..93
F.G.F.
22 .24
39
OBSERVATIONS OF HORIZONTAL MAGNETIC FORCE.
DATE.
1888.
Time of
one
H.K.M.T.
Vibra- tion.
Tem- perature Log mX.
Cent.
Value of
m.
H.K.M.T.
Distance in Centi- meters,
Tem- |perature Cent.
m
Deflec- tion.
Log
Mean.
Value of X,
Obser-
ver.
B
January 16,...
February 14,...:
March
April
14,...
17,...
May
15,---
3h. 3. p.
2 54 p. 3,5119 16 .55
3 23 p.
2 46 p.
2 58 P. 3.5252
July
17,...
3 12 p. 3.5349 31 4
August 14.... 3 0 p. 3.5348 30 .2
September 14,... 3 16 p. 3.5392 30 .5
October 15,... 2 55 p.
3,5410 29 .3
November 14,... 3 9 p.
3.5399 25. 1
December 14,... 3 18 p. 3.5407 23. 45
3.5186 25 .3
3.5181 22 .3
30 .2
3.5171 24°.0 2.35929 633.93
2.35952 633,51
2.35925 633.07
2.35892 632.40
2,35851 631.80
2.35666 629.20
2,35623 627.99
2.35492 626.89
2.35418 625.35
2.35359 624.47 4
2.35313 623.95
3h. 33m. p.
3 24
å
4 14 p. 30
3 17 P. 30
3 32 p. 30
7 p.
3 50 p.
4 13 p.
3 29 p.
10
5
¿
3 47
p. 30
8989898989898989898983
30
220,3
7° 28′ 6′′
3.24480
0.36077 F.G.F.
40
3 8 6
30
16,0
7 28 35
3.24400
40
3 8 10
22.4
7 26 50
3.24364
0.36121
0.36124 M.A.
39
40
3
7 36
21 .1
7 26 32
3.24307
0.36134 F.G.F.
40
3 7 27
28.6
7 24 50
3.24265
40
3 6 36
30
29.9
7. 22 45
3.24091
0.36135
0.36130 M.A
19
40
3 5 44
30
28 .5
7 21 51
3.23967
40
3 5 17
30
29 .1
7 21 16
3.23948
0.36164
0.36118
37
**
40
3 5 15
30
27.6
7 20 20
3.23807 0.36145 F.G.F.
40
3
4 42
30
23 .2
7 20 22
3.23742 0.36147 M.A.
40
3
4 51
21 .8
7 20 21
3.23716
0.36140 F.G.F.
40
3
4 50