1921.] 
Departmental Reports. 
13 
DEPARTMENTAL REPORTS. 
Mean Hourly Values of the Magnetic Declination and the 
Horizontal Magnetic Force. 
By H. F. Skey, B.Sc., Director of the Magnetic Observatory. 
(Communicated by the Surveyor-General.) 
Christchurch Observatory. (Latitude, 43° 3T*8 S.; longitude, 172° 37'*2 E.) 
Magnetic Declination , E. 16° + Tabular Minutes of Arc. 
Year 1917. 
G.M.T. 
Jan. 
Feb. 
Mar. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Annual 
Means. 
h. 
/ 
, 
P 
P 
/ 
P 
p 
/ 
f 
' 
P 
0 
52-8 
52*8 
51-5 
52*5 
53*1 
54*0 
53*8 
54*7 
53*4 
55*3 
56*2 
55*3 
53*8 
1 
54-3 
54-8 
54-3 
54*7 
54*9 
55*0 
55*0 
56*0 
55*5 
57*5 
53*6 
58*2 
55*7 
2 
55-0 
56-1 
56-3 
56*2 
56*3 
55*9 
56*2 
57*4 
57*8 
59*0 
60*2 
59*4 
57*1 
3 
55‘2 
56-2 
56-5 
56*8 
56*6 
56*2 
57*0 
57*9 
58*6 
59*2 
59*8 
59*8 
57*5 
4 
54-6 
55-3 
56-0 
56*0 
55*7 
55*9 
56*4 
57*5 
58*2 
58*4 
58*7 
58*8 
56*8 
5 
54-0 
54*1 
54-8 
55*0 
54*6 
54*7 
55*0 
56*0 
57*0 
57*2 
57*0 
57*4 
55*6 
6 
53-1 
52-7 
53-3 
53*9 
53*5 
54*2 
54*2 
54*3 
55*7 
55*4 
55*4 
55*5 
54*3 
7 
52-5 
52-2 
52-9 
53*2 
52*9 
53*7 
54*4 
55*2 
55*1 
55*0 
54*7 
54*3 
53*8 
8 
51-9 
51*8 
52*2 
52*7 
52*5 
53*5 
53*8 
53*7 
54*5 
54*0 
53*9 
54*2 
53*2 
9 
51*4 
51-7 
51-6 
51*7 
51*6 
52*8 
53*0 
53*4 
54*0 
53*3 
53*8 
53*1 
52*6 
10 
50-6 
50-8 
51T 
51*5 
51*6 
52*4 
52*6 
52*3 
53*1 
52*4 
52*8 
52*4 
52*0 
11 
50-5 
50-5 
51-3 
51*3 
51*1 
52*3 
52*2 
52*8 
52*5 
52*3 
52*7 
52*5 
51*8 
Noon 
50*2 
50-8 
51T 
51T 
51*7 
52*3 
52*2 
52*3 
51*7 
52*0 
52*8 
52*1 
51*7 
1 
49-9 
51-0 
51*2 
51*1 
52*7 
52*7 
51*8 
52*9 
52*6 
52*5 
53*0 
52*6 
52*0 
2 
50*1 
51-2 
51*5 
51*9 
52*7 
52*8 
52*5 
52*2 
53*0 
53*1 
52*6 
52*8 
52*2 
3 
503 
50-8 
51*3 
52*2 
53*1 
53*3 
52*2 
53*0 
53*3 
53*5 
52*9 
53*1 
52*4 
4 
50"6 
51-2 
51*5 
52*6 
53*2 
53*6 
53*2 
53*5 
53*6 
53*3 
53*0 
52*4 
52*6 
5 
50-2 
50-9 
51*5 
52*3 
53*0 
53*4 
53*8 
54*1 
54*0 
53*3 
53*0 
51*8 
52*6 
6 
49-5 
50-3 
51*8 
52*3 
52*9 
53*4 
53*6 
54*0 
53*6 
52*9 
51*7 
50*4 
52*2 
7 
48-4 
48-9 
50*3 
51*8 
52*9 
53*2 
53*6 
54*3 
52*8 
51*4 
49*7 
48*5 
52*1 
8 
46-6 
47-2 
48*2 
51*0 
52*6 
53*3 
53*4 
53*2 
51*0 
49*8 
48*2 
47*6 
50*2 
9 
46-0 
46-3 
46*7 
49*7 
51*5 
52*7 
52*4 
51*8 
49*4 
48*4 
47*8 
47*2 
49*2 
10 
47-4 
47-6 
46*5 
49*1 
51*2 
52*6 
51*8 
51*0 
48*8 
49*4 
48*8 
48*9 
49*4 
11 
49-3 
50-3 
48*3 
49*7 
51*4 
52*6 
51*9 
51*8 
49*8 
51*6 
51*8 
51*5 
50*8 
Monthly 
means 
51-0 
51-5 
51*7 
52*5 
53*1 
53*6 
53*6 
54*0 
53*7 
53*8 
53*7 
53*3 
53*0 
The mean value of the magnetic declination for the year 1917 is 
E. 16° 53' 
