The output of _Peru_, as now produced, seems to depend upon high prices and with such prices could probably remain at the level of 1916 for several years. The Huaura deposits are reported to be large, though of low grade, and may under proper management yield much ore even at lower prices. They were under the control of German firms during the war and probably still are. =North America.=--Until 1911 the _United States_ was the leading tungsten-producing country, but in that year it was passed by Burma, which kept the lead until 1916, when the United States again became the principal miner of tungsten ore. In 1918 China entered the excessively high-priced market with an output that exceeded by nearly 1,000 tons the world’s production of any year before 1915. North America increased its output from 1,549 tons in 1913 to 6,512 tons in 1917, but dropped back nearly 1,000 tons (to 5,406 tons) in 1918. In the United States the decrease of production was due almost wholly to the fall in price, and only partly to exhaustion of deposits. In the Boulder, Colo., tungsten field some of its best ore bodies are worked out and the cost of production has risen greatly owing to the impoverishment of others, and the same thing is true in some other places, but it seems possible that in the country as a whole the production can be made about equal to what it has been before, _provided prices are equally high_, through the discovery of the contact-metamorphic deposits of the Great Basin. In _Mexico_ the tungsten deposits are seemingly a continuation of those of southern Arizona. So far as known, all the Mexican deposits carry scheelite, in places partly replaced by cuprotungstite. The known worked deposits in the Sahuaripa district of Sonora are described as veins containing scheelite with copper minerals and a pegmatite dike in which are large masses of scheelite and molybdenite.