The great copper belt in the Katanga district,[65] commences about 100 miles north-west of the British South African post, Ndola (situate twelve miles south of the Congo border), and extends thence, in a north-westerly direction, for a distance of 180 miles, with an average breadth of twenty-five miles. "In the not far distant future, when the many problems of development are solved, the Katanga copper belt," says Mr. J. B. Thornhill,[66] "will be one of the controlling factors in the copper supply of the world." In the report of the British South Africa Company for the year ending March 31, 1914, it was stated that the copper-mining industry in Katanga had attained to considerable dimensions; that furnaces with a capacity of 1,000 tons of copper per month were at work, and that further large additions to the plant were being made. Katanga has, also, a tin belt, and coal, gold, iron and other minerals are found there, besides. In the German territory on the eastern side of Lake Tanganyika there are, indeed, minerals; but they are found in no such abundance as in the Belgian territory on the western side of the lake. German East Africa can, however, produce in great abundance the wheat, the rice and the other food supplies necessary for the workers in Katanga mines, and the German view has been that the eastern and the western sides of the lake should be regarded as complementary the one to the other, and that the Tanganyikabahn should convey these food supplies to the lake, for transfer to the other side by steamer, and bring back the products of the mines for distribution, via the German east coast route and the Indian Ocean, among the markets of the world. In the same way it was hoped that all goods and necessaries likely to be imported into the Katanga and Mweru districts from Europe would reach their destination via this German East Africa Central Railway; and German business houses were strongly advised to establish branches in those districts,[67] so that, apparently, Germany would eventually control the trade as well as the transport of "the other side of Tanganyika." The development of the south-western section of Germany's east-coast Protectorate had, in itself, become a matter of vital importance ("eine Lebensfrage"[68]); but the Belgian Congo was the only quarter to which that section could look for markets for its produce. The possibility of securing sufficient traffic for the Central Railway to ensure its financial success may have been a secondary consideration; but the railway itself was to serve a most important purpose, economically, by helping Germany to capture the Tanganyika and trans-Tanganyika trade, and by making her East Africa colony more prosperous; politically, by strengthening her hold on the Belgian Congo through the increase of her commercial interests there; and strategically, by affording her the means of effecting a speedy concentration of troops in Central Africa, should the occasion for so doing arise.