APPENDIX I.

MAGNETICAL OBSERVATIONS, 1893.

Made at the Kew Observatory, Richmond, Lat. 51° 28′ 6′′ N. and Long. 0 1m 151 W., height 34 feet above mean sea-level.

The results given in the following tables are deduced from the magnetograph curves which have been standardised by observations of deflection and vibration. These were made with the Collimator Magnet K.C. I. and the Declinometer Magnet marked K.O. 90 in the 9-inch Unifilar Magnetometer by Jones.

The Inclination was observed with the Inclinometer by Barrow, No. 33, and needles 1 and 2, which are 3 inches in length.

The Declination and Force values given in Tables I to VIII are prepared in accordance with the suggestions made in the fifth report of the Committee of the British Association on comparing and reducing Magnetic Observations.

The following is a list of the days during the year 1893 which were selected by the Astronomer Royal, as suitable for the determination of the magnetic diurnal variations, and which have been employed in the preparation of the magnetic tables :

:

7, 8, 15, 25, 26. 1, 11, 13, 26, 27. 10, 13, 18, 19, 20.

4, 9, 21, 22, 23.

2, 14, 17, 21, 28.

8, 13, 17, 22, 24. 5, 6, 10, 30, 31. 1, 9, 16, 17, 27. 4, 7, 13, 23, 24.

September

October.....

9, 11, 16, 21, 22.

-1.4 -2.0 -3.1 -4.5 -53 -5.7 -44-17+2·1

35.1
33.7 32.9
34.2 31.9
28.6 27.6

34.5 33.8 33.3 32.8 32.0

31.8 31.4

31.4

27.4 26.7
27.7

25.7

32.5 32.1 32.0 31.6 31.3 31.1 31.6 30.9 30.5 30.3 30.5 30.4 27.0 26.5 25.9 25.1 25.1 24.9 24.7 26.2 26.0 25.0 24.7 24.5 24.5 27.1 26.9 26.4

31.2

30.1

24.8

25.6

25.4

25.4 25.1

32.2

35-9 38.7 38.5 36.8 34.6 32.4 31.1
36-5 37.9 37.0 35.3 32.7 30.9 29.7 29.4
34.0 35-8 36.0 34.4 32.9 31.4 30.4 29.5
32.3 33.9 34.4 33.3 31.0
27.5 26.6
33.9 35.6 35.2 33.5 31.3
33.9 34.7 34.5 32.6 30.3

31.1

31.0

31.0
29.5 29.6 29.4 29.1
29.4 29.2 29.5 29.1
26.5
27.7
27.1

30.8 30.6

30 4

29.2

29.2

26.8 27.2 27.1

26.6

27.7 27.6

27.6

27.6

26.9 26.7

25.8 25.6

+56 +7.3 +7·1+5·5 +33 +14 +0.3-0.1-0.3 -0.3 -0.3 -0.6 -0.7

+36 +47 +44 +33 +2.2 +1.2 +0·8 +0.3 -0.3 -0.7 -0.8-1.0-1.0

+46 +60 +5·7 +44 +27 +13 +0.5 +0·1 −0·3 −0·5 -0.5 -0.8 -0.9

points to the west of its mean position.

Table III.-Hourly Means of the Horizontal Force in C.G.S. units

+00002+00002+00002 +00003 +00004+00005+00005+00004-00001

Annual mean.

+00004+00003 +00003 + ·00004 +00004 +00004 +00002 — 00001 -00008--00018

NOTE.-When the sign is + the

(corrected for Temperature), as determined from the selected quiet Days in 1893.

- -00022-00014-00004+00004+00008+00012 + 00014+00015+00015+00015 + 00012 +0001+00010]

Winter mean.

00016 00010 00005

00003 *00000 +00002 +00006 +00007 +00007+00008 +00007 + *00007 +00006

Annual mean.

00019 00012 00004

•00000 +00004 + ·00007 + ·00010+ ·00011+00011+00011+00009 +00009 +00008

reading is above the mean.