at water to be precipitated, and to
accumulate in the bottom of these boggy pools. In ancient days these bog
deposits of iron often alternated with coal layers. Millions of years
have passed since these two useful substances were laid down. To-day the
coal is dug, along with the bog iron. The coal is burned to melt the
iron ore and prepare it for use. It is a fortunate region that produces
both coal and iron.

Bituminous coal is plentiful, and scattered all over the country, while
anthracite is scarce. The cheapest iron is made in Alabama, which has
its ore in rich deposits in hillsides, and coal measures close by,
furnishing the raw material for coke. The result is that the region of
Birmingham has become the centre of great wealth through the development
of iron and coal mines.

Where water flows over limestone rock, and percolates through layers of
this very common mineral, it causes the iron, gathered in these rock
masses, to be deposited in pockets. All along the Appalachian Mountains
the iron has been gathered in beds which are being mined. These beds of
ore are usually mixed with clay and other earthy substances from which
the metal can be separated only by melting. The ore is thrown into a
furnace where the metal melts and trickles down, leaving behind the
non-metallic impurities. It is drawn off and run into moulds, where it
cools in the form of "pig" iron.

The first fuel used in the making of pig iron from the ore was charcoal.
In America the early settlers had no difficulty in finding plenty of
wood. Indeed, the forests were weeds that had to be cut down and burned
to make room for fields of grain. The finding of iron ore always started
a small industry in a colony. If there was a blacksmith, or any one else
among the small company who understood working in iron, he was put in
charge.

To make the charcoal, wood was cut and piled closely in a dome-shaped
heap, which was tightly covered with sods, except for a small opening
near the ground. In this a fire was built, and smothered, but kept going
until all the wood within the oven was charred.

This fuel burned readily, with an intense heat, and without ashes.
Sticks of charcoal have the form of the wood, and they are stiff enough
to hold up the ore of iron so that it cannot crush out the fire. For a
long time American iron was supplied by little smelters, scattered here
and there. The workmen beat the melted metal on the forge, freeing it
from impuritie