12 
MR. A. \¥. RUCKER AND DR. T. E. THORPE OX A MAGNETIC 
ComjKirison at Kew of Declination Observations made with the Survey and 
Keiv Instruments. 
As it will be convenient to discuss each magnetic element rather than each 
instrument separately, we begin by tabulating the Declination Observations. 
Comparisons of Magnetometer 60 with the Kew Standard Instrument. Observer, 
Mr. Gray. 
Date. 
s 
(Survey Instrument.) 
K 
(Kew Instrument). 
1 
K-S=/3. 
K-/3=K'. 
S-K'. 
June 3,1890 . 
1°7 5l'4 
1°7 52-2 
+ 0-8 
17 51-9 
-0-5 
'3, „ • ■ 
17 53-7 
17 54-4 
+ 0-7 
17 54-1 
-0-4 
4, , . . 
17 5T2 
17 51-5 
+ 0-3 
17 51-2 
0-0 
„ 4, „ . . 
17 52-5 
17 51-9 
-0-6 
17 51-6 
40-9 
„ 5, „ . . 
17 54-7 
17 54-9 
+ 0'2 
17 54-6 
40-1 
„ 5, „ . . 
17 55-6 
17 56-1 
+ 0-5 
17 55-8 
-0-2 
6, „ . . 
17 49 3 
17 49-6 
+ 0-3 
17 49-3 
0-0 
/3= +0‘3 
Mean 
= ±0-30 ! 
Nov. 12, 1891 . . 
17 40-8 
17 42-5 
+ 1-7 
17 41-9 
-1-1 
„ 12, „ . . 
17 42-9 
17 44-3 
+ 1-4 
17 43-7 
-0-8 
„ 18, • . 
17 45 0 
17 45-2 
4-0-2 
17 44-6 
40-4 
„ 18, ,. . . 
17 44-4 
17 44-7 
+ 0-3 
17 44-1 
40-3 
„ 18, „ . . 
17 44-8 
17 45T 
+ 0-3 
17 44-5 
40-3 
„ 18, ., . . 
17 44-4 
17 45-5 
+ 1-1 
17 44-9 
-0-5 
„ 18, „ . . 
17 46-4 
17 45-4 
-1-0 
17 44-8 
41-6 
/l=+0-6 
Mean 
= ±0-71 
Oct. 24, 1892 . . 
17 36-3 
17 36-7 
+ 0-4 
17 36 2 
40-1 
„ 24, „ . . 
17 39T 
17 39-6 
-f 0-5 
17 39-1 
0-0 
„ 25, . . 
17 36-8 
17 37-2 
-1-0-4 
17 36-7 
40-1 
„ 2.', „ . . 
17 39 0 
17 39-7 
4-0-7 
17 39-2 
-0-2 
/3=: 4-0-5 
Meaji 
= ±0-10 
