—Cassiterite occurs in pegmatite, intrusive into granite, in the Erongo Mountains east of Brandberg, and some placer tin deposits have been worked. On the whole the region does not seem to be particularly promising.
PROBABLE CHANGES IN KNOWN GEOGRAPHICAL DISTRIBUTION
It seems reasonably certain that England is in a position to keep producing a large part of the world’s tin for some time, the lessening output from the Malaysian provinces being offset by the increased production of the African colonies. Both Cornwall and Australia, it is believed, will be able to maintain for a number of years a rather steady output of about the present size.
Bolivia will doubtless be able to increase her output of tin, and probably both Siam and China can be expected to produce larger quantities in the future. Production of the Dutch East Indies can probably be maintained at about its present rate for a number of years.
POLITICAL CONTROL
As will be seen from [Table 62] and [Figure 10], Great Britain controls politically over 50 per cent. of the tin output of the world, in that her political influence is absolute in England, Africa, Australia, and all of her colonial possessions on the east side of the Indian Ocean; and there can be little doubt that the strong British policy with regard to the eastern colonies is also potent with respect to Siam and China.
Fig. 10.—Political control of tin deposits and tin smelters, based on estimates for 1918.
Holland controls the tin output of the East Indian island colonies, in which there are smelting works that seem capable of taking care of most of the ore mined. Holland consumes little tin herself and has approximately 16 per cent. of the world’s supply at her disposal. Prior to the war Holland was a large distributor of tin, but during the war tin from her colonies was sent direct to America and England, the largest consuming countries.
China has a rather feeble political control of the output of the Yunnan tin mines, but as that part of her production which reaches the rest of the world is exported through French territory, largely through English middlemen, her actual control is not particularly great.