24 
MR. A. W. RtlCKER AND DR. T. E. THORPE OX A MAGNETIC 
Comparisons at Kew of Dip Circle, No. 74, with the Kew Standard. 
Date. 
Observer. 
S 
(Survey 
Instrument). 
K 
(Kew 
Instrument). 
K-S=^. 
K-/J=K'. 
S-K'. 
Sept. 30, 1887 
R. 
67 3hl 
6°7 35-4 
+ 6-3 
o / 
67 34-8 
+ 6-3 
Oct. 19, „ . . 
R. 
67 34-2 
67 35-1 
+ 0-9 
67 34-5 
-0-3 
^=+0-6 
Mean 
= ±0-3 
June 2,1890 . . . 
G. 
67 31T 
67 32-0 
+ 09 
67 31-6 
-0-5 
,, .3, „ ... 
G. 
67 32-3 
67 .32-6 
+ 0-3 
67 32-2 
+ 0-1 
„ 4, „ ... 
G. 
67 31-6 
67 31-2 
-0-4 
67 30-8 
+ 0-8 
„ .5, „ . . . 
G. 
67 29-9 
67 31-0 
+ 1-1 
67 3U‘6 
-0-7 
„ 6, „ ... 
G. 
67 32-2 
67 32-4 
+ 0-2 
67 32'0 
+ 0-2 
/3=+0-4 
Mean 
= ±0’5 
March 25, 1892 . . 
G. 
67 .30-9 
67 31T 
+ 0-2 
67 30-3 
+ 0-6 
„ 25, „ . . 
G. 
67 30T 
67 31-6 
+ 1-5 
67 .30-8 
-0-7 
13=+0-8 
Mean 
= ±0-6 
Oct. 24, 1892* . . 
G. 
67 32-1 
67 31-2 
-0-9 
67 31-8 
+ 0-3 
„ 24, „ . . 
G. 
67 32-3 
67 31-4 
-0-9 
67 32-0 
+ 0-3 
„ 24, „ . . 
G. 
67 32-3 
67 31-3 
-1-0 
67 31-9 
+ 0-4 
25 
G. 
67 31-0 
67 30-9 
-0-1 
67 31-5 
-0-5 
OK 
G. 
67 30-5 
67 30'5 
0-0 
67 31T 
-0-6 
„ 25, „ . . 
G. 
67 31-1 
67 30 2 
-0-9 
67 30-.8 
+ 0-3 
/3=-0-6 
Mean 
= ±0-4 
* Tlie Observations in October were made with Needle No. 1, and with Needle No. 1 belonging 
Dip Circle 83, see p. 7. 
