s in 1880 to 365,000 tons seventeen years
later, and if continued the yearly production by 1920 will amount to
580,000 tons, or more than a billion pounds.

The principal lead-producing states are Missouri, Idaho, Utah, and
Colorado. In Missouri it is probable that the present rate of increase
could be kept up for at least fifty years. The other states could keep
up the present production for many years but could not greatly increase
it without exhausting the supply.

As with most mineral resources in the United States, it is only the
richest ores that are now drawn upon (except where lead is a by-product
extracted with some other ore). If prices would advance, so as to make
the low-grade ores profitable, the amount of our resources would be
greatly increased.

There is little waste in the mining or smelting of lead ores, and the
slag, the waste, is always ready to be used again. In the refining and
concentrating of lead the loss often amounts to as much as fifteen per
cent. or twenty per cent. The best way to prevent final loss is to store
all refuse until such time as the reworking becomes profitable.
Improvement in methods has been great in the last fifteen years but more
economical methods everywhere will be one of the necessities of the
future. We can see that the lead resources of the United States are not
large and that when our own supply is exhausted we can not turn to the
rest of the world.

The waste in mining is not large, and most of it can not be avoided at
present prices; so that for the conservation, which we see is so
important, we must turn to the uses of lead. The most necessary of these
is for lead pipes in plumbing. Another use is for war supplies, which
not only makes heavy drains on our stores of coal and iron, but also on
lead, which is much less plentiful.

One ton out of every three produced in the United States is used in the
manufacture of white lead and consumed as paint. This, of course, is
entirely lost, and it seems that some other material might be used,
instead of so valuable a mineral, especially when the resource is not
abundant. White lead is used more than any other substance for paint,
although zinc white has come into considerable use in the last few
years. No other nation uses lead paint to such an extent as does the
United States, partly because no other nation could afford so general a
use of such an expensive material, and partly because so many wooden
buildings are erec