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WELDING AND CUTTING
As mentioned in the previous chapter,
gas welding, using oxygen and hydrogen, dates back to the 1850s.
However, the oxy-hydrogen flame is virtually
useless for welding steel. Gas welding, to be broadly useful, had to
await the discovery of the remarkable
properties of the oxy-acetylene flame, and of a way to make acetylene at
reasonable cost. These events took place
in the 1890s.
Acetylene gas is unknown in nature.
Edmund Davy, a famous British chemist, is generally considered the first man
to make acetylene. In 1836, attempting
to produce potassium metal, he came up with a black compound
(potassium carbide) which reacted with
water to produce a gas which burned with great brilliancy. He thought it
would make an excellent illuminating
gas if it could be produced at moderate cost. That was not possible, using
potassium carbide as the starting point.
Calcium carbide (which, like acetylene, does not exist in nature) was not
made and identified until 1862. Like
potassium carbide, it reacted with water to form acetylene. Again, the process
by which it was first made did not offer
Although calcium carbide was undoubtedly
accidentally produced in electric furnace operations before 1892, not
until that year was it produced and
identified both in France and the U.S. In both cases, the experimenters were
trying to make something else. The Frenchman
did not immediately recognize the potential commercial value of
what he had created. The Americans did.
Major J. Turner Morehead and Thomas
L. Wilson, using an electric furnace they had set up in Spray, N.C., were
attempting to make calcium metal from
a mixture of quicklime and coal tar. If successful, they hoped to use the
calcium to reduce aluminum oxide and
come up with aluminum metal. However, the product of their electric
furnace run was a dark crystalline mass
which reacted violently with water. They had found a way to make
acetylene economically, and they were
not slow to recognize the value of their discovery. Because they sent a
sample of the calcium carbide to Lord
Kelvin in England, together with details on the method by which they had
produced it, by 1895 calcium carbide
plants were operating in both England and France, as well as in the U.S.
Plants in Norway and Switzerland followed