44 SCIENCE IN AFRICA 



of Tanganyika of 55 kilometres, 1° 30' to 1° 00' S. For the com- 

 pletion of this small stretch the Belgians are ready to co-operate 

 and have finished the preliminary reconnaissance work. Alter- 

 natively it could be carried entirely through British territory 

 by deviating through Tanganyika, at an approximate cost of 

 j(^2,ooo, if in conjunction with other work, or ;;(^6,ooo if the subject 

 of a special expedition. 



Passing north, the Uganda sector from 1° S. to 10' N., was com- 

 pleted by a special Anglo-Belgian operation carried out in imme- 

 diate sequence to the Boundary Commission of 1908. Following 

 on this, there is a large gap comprising a small piece of Northern 

 Uganda, 275 kilometres, and the whole of the Sudan, as far as the 

 Egyptian border at 22° N. The portion from the Egyptian frontier 

 to Cairo was completed in 1930: quoting from a statement by 

 F. S. Richards: 'Geodetic survey was started in Egypt in 1908 with 

 the object of completing the Egyptian portion of the 30th meridian 

 arc. Before starting work Captain H. G. Lyons (Sir Henry Lyons) 

 sought the best advice available and eventually decided to use 

 methods similar to those used by Sir David Gill at the Cape. So 

 well was the foundation laid that there has been practically no 

 change in methods or instruments up to the present time. The 

 triangulation chain from Cairo to Haifa, which is claimed to have 

 as high a degree of precision as any geodetic survey in the world, 

 was completed in 1930.'^ 



The importance of completing this arc is stressed by every 

 authority on the subject. The Ruanda-Urundi gap would be easy 

 to close, since the country is open and most of the necessary expen- 

 sive instruments used recently by Major Hotine are already in use 

 by the geodetic branch of the survey departments in Tanganyika 

 and in Northern Rhodesia. The Sudan gap presents greater diffi- 

 culties; the northern part from the Egyptian border to Khartoum 

 is easy desert country, and its completion would consist simply in 

 extending the Egyptian work, but the southern part from Khar- 

 toum to Uganda cuts directly through the sudd area of the White 

 Nile, where triangulation is recognized to be impossible, so devia- 

 tion is necessary. The best way would be to make a complete 

 circuit round the sudd area, but, if this involves too much work, 



^ Private Memorandum. 



