nine of
them are west of the Mississippi River and most of these are in
Missouri. The greatest of all the iron regions now lies in upper
Michigan and Minnesota. This furnishes eighty tons out of every one
hundred mined in the United States, but the smelting is done along the
southern shores of Lake Michigan. The reason for this is that the iron
region itself is far distant from a cheap fuel supply. Pittsburg,
Pennsylvania, has been the great iron city of the United States on
account of its nearness to great supplies of both coal and iron.
Birmingham, Alabama, is the heart of the great smelting region of the
South.

The iron is divided into districts as follows:

(1) The Northeastern, comprising the states of Vermont, Massachusetts,
Connecticut, New York, New Jersey, Pennsylvania, Maryland, and Ohio,
supplies a little more than five per cent. of the iron mined in the
United States.

(2) The Southeastern, containing Virginia, West Virginia, eastern
Kentucky, and Tennessee, North and South Carolina, Georgia, and Alabama,
gives us twelve per cent. of our iron.

(3) The Lake Superior district, containing the northern parts of
Michigan, Minnesota and Wisconsin, supplies more than eighty per cent.

(4) The Mississippi Valley district contains western Kentucky, and
Tennessee, Iowa, Missouri, Arkansas and Texas. This region furnishes
less than half of one per cent. of the total supply.

(5) The Rocky Mountain district contains Montana, Idaho, Wyoming,
Colorado, Utah, Nevada, New Mexico, Arizona, western Texas, Washington,
Oregon and California; and all this great region now supplies but a
little more than one per cent.

The official report, which is as thorough as can be made but is
naturally subject to mistakes, gives the amount of available iron, that
is, that which can be mined under present conditions, as nearly five
billion tons.

Let us see how long this may be expected to supply the demand.

Before 1810 the amount of iron ore produced was so small as to be
scarcely worth considering. From 1810 to 1870 a little less than fifty
million tons were mined, from 1870 to 1889 nearly 154,000,000 tons, and
from 1889 to 1907, 475,000,000 tons, or altogether nearly 680,000,000
tons. The production has been found to double itself about every nine
years. In 1907 alone it was 52,000,000 tons or about one-thirteenth of
all that has been mined.

In 1880 we used 200 pounds of pig-iron for every man, woman, and child
in the c