(57) 
TEUE ISOGONICS, ISOCLINALS, AND LINES OF HOEIZON- 
TAL INTENSITY FOE THE NOETH-WESTEEN PAETS OF 
THE UNION OF SOUTH AFEICA AND FOE PAET OF 
GEEAT NAMAQUALAND FOE THE EPOCH JULY 1, 1908. 
By J. C. Beattie, D.Sc, Professor of Physics, South African College, 
Cape Town. 
(Eead July 16, 1913.) 
(With Three Maps, Plates III., IV., V.) 
The results used in the preparation of the magnetic charts given in 
the following paper were obtained at various times from 1900 to 1913 ; the 
earlier observations in the south-west part of the Cape Province had 
already been used in preparing magnetic charts for the epoch July 1, 
1903 ; f these have been reduced to the later epoch by using the values 
obtained at repeat stations at Cape Town, Ceres Eoad, and Matjesfontein. 
Some of the observations in the Kenhardt, Carnarvon, Fraserburg, Suther- 
land, Prince Albert, and Beaufort West districts had also been used, and 
these were reduced to the new epoch by repeat observations at Fraserburg 
Eoad, Beaufort West, Hutchinson, Van Wyk's Vlei, and Kenhardt ; the 
previously used results in the Transvaal and the Free State were reduced 
by the help of repeat observations at Karree, Warrenton, Mafeking, 
Klerksdorp, and Orange Eiver. The new results embodied in the present 
charts lie chiefly in the north-west of the Cape Province, in German 
South-West Africa,! and in Bushmanland ; in addition a number of 
additional stations were occupied in the Western Transvaal and in British 
* The work has been carried out with the help of grants in and from the Union 
Government, the London Eoyal Society, the British and the South African Associations 
for the Advancement of Science. 
t " Keport of a Magnetic Survey of South Africa," by J. C. Beattie. London, 1909. 
I "On Magnetic work in Southern and Central Africa," by J. 3. Beattie and J. T. 
Morrison. Washington, 1913. 
