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Mining
-- First Use of the Steam Engine
Little, if any, valuable ore was
found in the river valleys supporting systematic agriculture. On the other
hand, those living in the highlands had learned to work shallow pits for
copper and gold, two soft minerals that could be worked into jewelry and
other items of limited utility. When tin was found and mixed with copper,
an amalgam was developed giving its name to a lengthy Bronze Age, a technological
period when men first made tools and weapons from metal. Casting was well
established in the Middle East in 3500 B.C. Probably that era's heaviest
commerce was between those who raised an excess of food but desired metals,
and those unable to raise crops but knowing how to bring other valuables
out of the earth. Various mixtures of these malleable metals brought forth
fastenings for wooden gears and machines some of which were used for lifting.
Iron was also known in the Middle East about 3000 B.C., but did not come
into wide use for another 1000 years when it was found that iron ore could
be softened with the intense heat created by burning coal and injecting
forced air. This combination of coal and iron created metal that could be
cast in molds or beat into the hardness required to make the sturdier gearing
and machines that would take the heavier pressure of the steam gradually
being harnessed. First came an atmospheric device to pump water out of mines,
being sunk ever-deeper to find the iron and coal combination that drove
the Industrial Revolution in England, then Europe. When the Newcomen reciprocating
engine was given rotary motion by James Watts in 1769, men and ore could
be more quickly moved between the mine's lower levels and the surface.
The emphasis upon lifting water for crops, that had given way to the lifting
of earth and stone for ever towering structures, gave way to devices that
took men deeper and deeper into the bowels of the earth to harvest minerals
more precious than gold! |
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