526 KEPonx— 1887. 



mining being mainly confined to the south-eastern slopes of the Ural 

 Mountains. The reason of this uniformity of yield is the vast area over 

 which the workings extend. The yields of the various districts have 

 varied much, but the average production of the whole is fairly steady. 



Since 1829 Siberia has been the chief source of Russian gold. From 

 1867 to 1874 it yielded from two-thirds to three-fourths of the total 

 amount. 



In 1860-67 the Ural district yielded about 20 per cent, of the total 

 production ; in 1872 this fell to l7Tf per cent., and in 1877 to 16 per 

 cent. Since that date it has still further decreased. The yield of eastern 

 Siberia has risen, and in 1877 amounted to 78 per cent, of the whole. 



The modern developments of Russian gold-mining have been in the 

 extreme east, in the basins of the Amur and the Lena ; here, as elsewhere 

 in Siberia, entirely in alluvium. Much of the ground is perpetually 

 frozen, and has been so probably since the Glacial period. This frozen 

 condition of the gravels has protected them from denudation ; but for 

 this much more would have been swept into the sea by the summer floods. 

 The preservation of the Siberian placers is thus due to frost ; those of the 

 Californian and Victorian placers to volcanic action. 



The vast extent of unworked placers in Eastern Siberia will yield a 

 steady supply for many years to come. But the older placer workings in 

 other areas will fall off in yield, and therefore it would not be safe to 

 anticipate a yearly increase to the world's annual production from this 

 source. There is one point, however, to be borne in mind. The source 

 of the gold must be in the Altai and in the ranges of mountains to the 

 east. All this is practically unexplored ; and we may fairly anticipate 

 the discovery here of quartz veins, which will probably help to keep up 

 the supply of Siberian gold when the yield from tbe placers declines. 

 Very little is known of the geology of this region, but the existence of 

 Silurian rocks has been proved. 



African Gold Coast. — This has long been known as a source of gold, 

 and the amount of the metal thence exported must in the aggregate have 

 been very considerable. There are no means of ascertaining the amounts 

 obtained, and hence the wildest estimates are made. 



It has been stated that Western Africa during part of the last century 

 produced over 3,000, OOOZ. of gold yearly. Similar estimates have been 

 made for South-eastern Africa during the Portuguese rule. But Dr. 

 Soetbeer's estimate for the whole of Africa is a yearly average of 

 279,000Z. from 1701 to 1740, and of 2(j9,2o0l. from 1741 to 1800. It is 

 probable that the yearly production of the whole world during the last 

 century rarely exceeded 3,000,000/., and that only during the maximum 

 period of the Brazilian placers. We need not, however, doubt the exist- 

 ence of rich alluvial tracts in Western Africa, which, after having been 

 drawn upon for centuries by hand labour, may yet for a while yield con- 

 siderable supplies if systematically worked. There must be numerous 

 auriferous reefs the denudation of which has yielded the gold of the 

 river gravels and of the seashore. Some of these have long been 

 known, and a few partially worked, and from them hereafter a somewhat 

 increased yield for West Africa may be expected. 



The quantity of gold exported from the British possessions at the 

 Gold Coast during 1884 is officially stated at 24,994 ounces, valued at 

 89,98U. 



South Africa. — No trustworthy data are available for ascertaining the 



