BRITISH ISLES FOR THE EPOCH JANUARY 1, 1915. 
7 
In the first two the observations were made in the Magnetic Pavilion, and 1 
determined my own azimuth by sun observation. In the third tlie observations were 
made a few yards from the Pavilion at the station selected by the O.S.O. and the 
azimuth was determined by the O.S.O. 
Horizontal Force. 
January 14, 1914. 
January 15, 1914. 
May 14, 1914. 
Survey value. 
18,575 
18,560 
18,565 
Greenwich value. 
18,548 
18,553 
18,553 
Difference. 
+ 27 
+ 7 
+ 12 
Mean . . +15 
Inclination. 
January 14, 1914. 
. 
January 15, 1914. 
May 14, 1914. 
Survey value. 
66 50'- 8 
66 50'-2 
66 49'- 4 
Greenwich value. 
66 50-6 
66 50-1 
' 66 50-0 
Difference. 
+ 0-2 
+ 0-1 
- 0-6 
Mean 
-o'-i 
It is here of interest to examine the values at Kew and Stonyhurst Observatories 
where observations were made and the observatory values supplied by Dr. Chree 
and Kev. Father Sidgreaves. 
Kew, May 27, 1914. 
D. 
H. 
I. 
Survey value. 
15 
28-9 
18,484 
66 56'-4 
Kew value. 
15 
30-0 
18,460 
66 56-2 
Difference. 
- ri 
+ 24 
+ 0-2 
Stonyhurst, September 17, 1914. 
D. 
H. 
I. 
Survey value. 
16 46'0 
17,376 
68 4l'-4 
Stonyhurst value. 
16 44-3 
17,362 
68 40-4 
Difference. 
+ 1-7 
+ 14 
+ 1-0 
In both these cases the observatory azimuths were used and were not determined 
by the O.S.O. Further, at Stonyhurst the spare dip needle was used, as No. 1 had 
gone out of order. 
