14 
MR. A. W. RUCKER AND DR. T. E. THORPE ON A MAGNETIC 
Comparisons of Magnetometer 70 with the Kew Standard Instrument. 
Observer, Mr. Watson. 
Date. 
s 
(Survey Instrument ) 
K 
(Kew Instrument.) 
K-S=/3. 
K-/3=K'. 
S-K'. 
April 16, 1891 . 
17 52-6 
1°7 48-7 
-3-9 
1°7 52-3 
+ 0'3 
,, 20 , 
17 49-4 
17 45-6 
-3-8 
17 49-2 
+ 0-2 ! 
„ 20, 
17 52-5 
17 48-6 
-3-9 
17 52-2 
+ 0-3 
„ 20, 
17 56-0 
17 53-2 
-2-8 
17 56-8 
-0-8 
„ 21, 
17 52T 
17 47-7 
—4-4 
17 51-3 
+ 0-8 
„ 21, 
17 47-4 
17 43-0 
-4-4 
17 46-6 
+ 0-8 
„ 22, 
17 51T 
17 47-6 
-3-5 
17 51-2 
-OT 
„ 22, 
17 48-6 
17 45-2 
-3-4 
17 48-8 
-0-2 
„ 23, 
17 52-3 
17 48-4 
-3-9 
17 62-0 
+ 0-3 
„ 23, 
,. . . 
17 48-3 
17 44-7 
-3-6 
17 48-3 
0-0 
„ 24, 
17 50-0 
17 47-2 
-2-8 
17 60-8 
-0-8 
„ 24, 
5 J 
17 47-6 
17 44-6 
-30 
17 48-2 
-0-6 
/ 3 =- 3-6 
Mean . 
= ±0-43 
Oct. 12, 
1891. . 
17 48-9 
17 46-2 
-2-7 
17 48-8 
+ 0-1 
„ 13, 
17 44-5 
17 43-2 
-1-3 
17 45-8 
-1-3 
„ 14, 
?5 
17 44-5 
17 40-6 
-3-9 
17 43-2 
+ 1-3 
„ 14, 
)> 
17 48-8 
17 46-0 
-2-3 
17 49T 
-0-3 
1 
/3=-2-6 
Mean . 
= ±0’75 
April 21, 
1892. . 
17 41-8 
17 39-6 
- 2-2 
17 41-8 
0-0 
M 21 , 
11 
17 41-8 
17 39-8 
-2-0 
17 42-0 
-0-2 
„ 21 , 
91 
17 45-0 
17 42-6 
— 2-4 
17 44-8 
+ 0-2 
„ 21 , 
11 * • 
17 44-8 
17 42-6 
— 2-2 
17 44-8 
00 
„ 21 , 
15 
17 42-8 
17 40-2 
- 2-6 
17 42-4 
+ 0-4 
„ 21 , 
55 
17 42-7 
17 39-7 
-3-0 
17 41-9 
+ 0-8 
„ 22 , 
55 
17 39-8 
17 38T 
-1-7 
17 40-3 
-0-5 
22 
55 
17 40T 
17 38-7 
-1-4 
17 40-9 
-0-8 
55 
17 44-9 
17 42-5 
-2-4 
17 44-7 
+ 0-2 
22 , 
55 
17 44-7 
17 42-6 
-2T 
17 44-8 
-OT 
/3=-2 2 
Mean . 
= ±0-32 
Oct. 7, 
1892 . . 
17 40-0 
17 .35-4 
-4-6 
17 38-6 
+ 1-4 
„ 7. 
55 
17 42T 
17 37-7 
— 4'4 
17 40-9 
+ 1-2 
„ 7, 
55 
17 40T 
17 37-8 
-2-3 
17 41-0 
-0-9 
„ 10, 
55 
17 38-9 
17 .36-7 
-2-2 
17 39-9 
-1-0 
„ 10, 
17 43-8 
17 40-8 
-3-0 
17 44-0 
-0-2 
„ 10, 
55 
17 42-5 
17 39-7 
-2-8 
17 42 9 
—0-4 
/3=-3-2 
Mean 
= ±0-85 
