et prices at the consuming centers, and can still
leave a fair margin of profit for the mining operation. The price
equilibrium between consuming centers affords a reasonably uniform basis
against which to measure availability of ores.

Figures of cost are obtainable as a basis for comparison of availability
of iron ores of certain of the districts, but not enough are at hand for
comparison of the ores of all districts. Careful study of costs has
demonstrated the availability in the near future of the Brazilian
high-grade Bessemer hematites; and projects which are now under way for
exportation to England and the United States will doubtless make this
enormous reserve play an important part in the iron industry. Iron ore
is known but not yet mined in many parts of the western United States
and western Canada. With the increasing population along the west coast
of North America, projects for smelting the ore there are becoming more
definite. Establishment of smelters on the west coast would make
available a large reserve of ore (see also, however, p. 155).

The list of changes now under way or highly probable for the future
might be largely extended. The use of iron and steel is rapidly
spreading through populous parts of the world which have heretofore
demanded little of these products. This increased use is favoring the
development of local centers of smelting, which will make available
other large reserves of iron ore. The growth of smelting in India, China
and Australia illustrates this tendency.

Iron ore reserves are so large, so varied, and so widely distributed
over the globe, that they will supply demands upon them to the remote
future. Reserves become available and valuable only by the expenditure
of effort and money. Ores are the multiplicand and man the multiplier in
the product which represents value or availability. Iron ore can be made
available, when needed, almost to any extent, but at highly varying cost
and degree of effort. The highest grade ores, requiring minimum
expenditure to make them available, are distinctly limited as compared
to total reserves. Any waste in their utilization will lead more quickly
to the use of less available ores at higher cost. One of the significant
consequences of the exhaustion of the highest grade reserves will be an
increased draft upon fuel resources for the smelting of the lower grade
ores. Availability of iron ores is limited, not by total reserves, but
by economic