56 PRESIDENTIAL ADDRESS SECTION P.. 



template the unpleasant fact that the life of the mine may he 

 approaching its end." 



'J he future of the Namaqualand copper region, where enor- 

 mous quantities of low-grade ore, averaging from i^^ to 2^2 

 per cent, of copper, are available in the existing mines and in tlie 

 hundreds of ore-bodies that have not hitherto been opened up,* 

 depends on the introduction of economical methods such as 

 leaching flotation for the beneficiation of this material. 



As pointed out by Trevor, f the ore in question is well i.vcr 

 the grade that is being profitably exploited on a vast scale in 

 the United States and in Chile, in areas just as inaccessible and 

 inhospitable, and there is no apparent reason, therefore, why 

 the introduction of modern methods of treatment should not 

 give this grand old mining field a new lease of life. 



At Messina it is a question of locating further rich ore- 

 bodies of the type being worked, which have been shewn to owe 

 their origin to a process of secondary enrichment by descending 

 solutions. Exploratory work has for several years past been 

 conducted by the management on approved scientific lines, and it 

 is to be hoped that their efforts will bear fruit. 



Tin. 



The tin production of the Union for 1917 shows a consider- 

 able decrease com]:)ared with 19 13. This is due to the fact that 

 during 1916 and 191 / poor zones were encountered at some of 

 the ])rincipal mines. At the present time the workings of all the 

 more important producers are in good, or fairly good, ore, and 

 if the high price of tin be maintained, it is not improbable that, 

 as regards value, the 1918 output will constitute a record. 



Apart from a small production of alluvial tin from the Kuils 

 River fields near Capetown, the whole of the output t comes from 

 the Bushveld province of the Transvaal, which includes two 

 distinct tin-bearing areas, known respectively as the W'aterberg 

 and the Olifants River fields. Of these the former, occupying 

 a large crescent-shaped area in the central portion of the Water- 

 berg district, are the more important. The output of the Olifants 

 River fields, which extend in a north and south direction from 

 the farm Mutue Fides, in the south-eastern corner of the Water- 

 berg district, to the Elands River, is, however, steadily increasing. 



The deposits of both areas exhibit an extraordinary diversity 

 of type, and are as yet but imperfectly understood. From the 

 experience gained in the different mines and i^-ospects. however, 

 one fact stands out. and that is that, within the limits of either 

 of these tin fields, it pays to follow up the merest indication. It 

 is also relevant to observe that fissure deposits in the quartzites 

 of the Rooiberg series and pipe occurrences in the Red (iranite 



* C/. Rogers, A. W. : Proc. Geol. Soc S.A. (1915). 21-3.;. 

 t Cy. The South African Year-Booh. 4..13. 



t The output of the alluvial tin-tields of Swaziland, amounting to 

 about 350 tons of concentrate per annum, is not inchided in the returns. 



