192 
Transactions of the Boyal Society of South Africa. 
Date. 
1906-53-1899-01 -- 
7-52 yrs. 
Secular Variation. 
Declination. 
-12' 
Dip. 
+ 4'-4 
Horizontal Intensity 
-66 
Date. 
1911-51 
1903-66 
Machadodorp. 
Declination. 
19° 31'-3 W. 
20 47-6 
(2, 4) 
Dip. Horizontal Intensity. 
59° 27'-3 S. -18411 
58 45-0 -19062 
Secular Variation. 
1911-51-1903-66 = 7-85 yrs. -9'-7 +5'-4 
— 837 
Mafeking-. (2, 3, 4) 
Date. 
1911-93 
1909-30 
1906-07 
1903-21 
1898-02 
Declination. 
21° 41'-0 W. 
22 10-8 
22 38-8 
23 08-3 
Dip. Horizontal Intensity. 
58° 10'-4 S. 
57 51-2 
57 33-8 
57 10-7 
56 31-1 
1911-93-1909-30 = 2-63 yrs. 
1909-30-1906-07 = 3-23 yrs. 
1906-07-1903-21 = 2-86 yrs. 
1903-21-1898-02 = 5-19 yrs. 
1911-93-1903-21 = 8-72 yrs. 
1911-93-1898-02 = 1 391 yrs. 
Secular VarioMon. 
-ll'-3 
-8-7 
-10-3 
-10-0 
+ 7'-3 
+ 5-4 
+ 8-3 
+ 7-6 
+ 7-1 
-18779 
-19010 
-19308 
-19501 
•19871 
-92y 
-68y 
-71y 
-79y 
Matjesfontein. 
(2, 3, 4, 5, 7) 
Date. 
Declination. 
Dip. 
Horizontal Intensity, 
1913-48 
26° 49'-8 W. 
61° 05'-6 S. 
•17124 
1912-48 
27 02-2 
60 57-8 
•17199 
1908-47 
27 44-1 
60 27-4 
•17607 
1906-50 
60 12-2 
•17792 
1905-09 
28 10-7 
60 06-2 
•17928 
1904-52 
28 16-2 1904-36 
59 57-8 
1904-52 -17923 
1903-00 
28 26-8 
59 47-3 
1900-47 
28 50-5 
59 25-3 
•18282 
1900-28 
28 46-6 
59 23-7 
1899-55 
59 18-1 
•18360 
