hundred hands.

[Illustration: RUNNING METAL INTO PIGS.]

The first process is melting the ore in the blast-furnace. Here the ore,
with coal and a flux of limestone, is piled in and subjected to the heat
of the fires, driven by a hot blast and kept burning night and day. The
iron, as it becomes melted, flows to the bottom of the furnace, and is
drawn off below in a glowing stream. Into the top of the blast-furnaces
the ore and coal are dumped, having been raised to the top by an
elevator worked by a blast of air. It is curious to notice how slowly
the experience was gathered from which has re suited the ability to
work iron as it is done here. Though even at the first settlement of
this country the forests of England had been so much thinned by their
consumption in the form of charcoal in her iron industry as to make a
demand for timber from this country a flourishing trade for the new
settlers, yet it was not until 1612 that a patent was granted to Simon
Sturtevant for smelting iron by the consumption of bituminous coal.
Another patent for the same invention was granted to John Ravenson the
next year, and in 1619 another to Lord Dudley; yet the process did not
come into general use until nearly a hundred years later.

[Illustration: CARRYING THE IRON BALLS.]

The blast for the furnace is driven by two enormous engines, each of
three hundred horse-power. The blast used here is, as we have said, a
hot one, the air being heated by the consumption of the gases evolved
from the material itself. The gradual steps by which these successive
modifications were introduced is an evidence of how slowly industrial
processes have been perfected by the collective experience of