ORIGIN AND PROGRESS OF GEODETIC SURVEY IN SOUTH AFRICA. 233 
The work was suspended during 1902 on account of the war, and 
recommenced in 1903. I selected Dr. Tryggve Rubin as officer in charge 
of the work in Northern Rhodesia. He had been a member of the 
Swedish-Russian expedition for measurement of the Spitzbergen are of 
meridian in the summer of 1901, and was leader of the expedition which 
completed that work in 1902. After residence for three weeks at the 
Cape Observatory he sailed for Chinde on April 29, 1903. He was 
joined by Mr. Tyrrell McCaw as chief assistant, who sailed from the Cape 
for Chinde on October 5 of the same year. There remained several 
points requiring occupation south of the Zambesi, and some others had to 
be re-selected, as further reconnaissance had shown them to be unsuitable 
for the northward extension. Dr. Rubin found, as Mr. Simms had 
found, extraordinary difficulties presented by haze, smoke, and heavy 
rains, and much of the first year was occupied with work connected with 
the Anglo-Portuguese boundary. Dr. Rubin’s last report brings his 
statement of its progress up to April 1905. 
In July 1902, during a visit to Lord Milner, then Governor of the 
Transvaal and Orange River Colony and High Commissioner for South 
Africa, I submitted plans and proposals for an ordnance survey of these 
Colonies. The original desire of Lord Milner was to have the topography 
of the country carried on pari passw with the principal triangulation, or, 
rather, to immediately follow the latter work in localities where maps 
were most urgently wanted. But in consequence of a proposal of the 
War Office for the formation of a central office for the execution of a 
topographic survey of South Africa, to which all South African Colonies 
were to contribute, I urged that the principal triangulation of the Trans- 
vaal and Orange River Colony should be first of all executed, in order to 
bring up their state of survey to a level with that of the Cape Colony 
and Natal. 
That course was adopted, and the work has been in steady progress 
ever since, under the energetic directorship of Colonel Morris, R.E., C.B., 
pressure of other work having compelled me to limit my offices to those of 
scientific adviser. 
So much for the history of the work. Let us now look at the results. 
The large map Plate II. shows the whole of the triangulation accom- 
plished in South Africa ; the different divisions of the work will be suffi- 
ciently evident from their geographical position. 
Although the whole of the triangles shown in the Transvaal and Orange 
River Colony have been selected and beaconed, the whole have not yet 
been completely measured. Diagrams | and 2, Plate ITI., show the chains 
which have been completed and reduced in the Cape Colony, Transvaal, 
Orange River Colony, and Natal, with the exception of the astronomical 
observations at the points to which no figures are attached. For these 
points the astronomical observations have been made, though not yet re- 
duced. The whole of the Bechuanaland and Damaraland triangulation, 
and its connection with Maclear’s arc, and the triangles near Kimberley 
have also been reduced. The survey in Southern Rhodesia has been com- 
pletely reduced. 
Tn Rhodesia the two northern triangles have not been observed, or, 
rather, the details of their measurement have not yet reached me, but the 
rest have been preliminarily reduced for the purposes of the present paper. 
The following are the base lines which have been measured, and 
from the following table it will be seen that they control, more or less 
