The experience and information gained during the war, largely during 1918, show conclusively, first, with respect to metallurgy, that 20 to 30 per cent. spiegeleisen, as well as 60 to 70 per cent. ferromanganese, instead of 80 per cent., may be used to make satisfactory grades of open-hearth steel without appreciably sacrificing rate of production or quality of product; and second, with respect to ore production, that known domestic deposits can supply for at least five and probably ten or more years, much more low-grade ore than is needed to make spiegeleisen, and for at least five years and possibly ten years, about one-third the high-grade ore needed for the manufacture of alloy with 60 to 80 per cent. manganese. The reader should note, however, that capacity of mines to meet demand is in large measure determined by the prices offered for the product, which during 1918 were about five times those prevailing before the war. Beyond doubt, at pre-war prices, the United States can not supply more than several per cent. of the high-grade ore needed to make ferromanganese. Citizens of the United States have not shown great interest in purchasing foreign deposits of manganese ore. With Cubans, they have controlled the mines yielding a large part of the Cuban output, and about 1907 one company, the Carnegie Steel Co., purchased several deposits in India. That company, however, seems to purchase ore, in addition to the output of its mines. Not until 1917 did Americans enter the Brazilian fields; then the largest deposits of the relatively unimportant Bahia district were purchased by a Philadelphia group. =England.=--Before the war, England received about 50 per cent. of her manganese ore from India, 40 per cent. from Russia, 3 per cent. from Brazil, and small quantities from Spain and Portuguese India. Some low-grade ore also came from Spain, Algeria, and Greece. Domestic production was scarcely 1 per cent. of imports. Exports of ferromanganese, largely to the United States, however, have been equivalent to 35 to 45 per cent. of the total imports of ore. Two effects of the war were to eliminate Russia as a source of ore, the deficit being made up from India, and greatly to curtail exports of ferromanganese. In contrast with the United States and Germany, Great Britain does not seem to contain deposits of low-grade ores capable of supplementing the needs of high-grade ore. England controls fully 90 per cent. of the Indian output, probably through ownership by resident English and native Indians. On the other hand, England seems to have no control, direct or indirect, of the output of Brazil, Russia, or of other important contributions to supplies.