sometimes the case with cheap portable outfits. Their use should not be
tolerated when any other method is available, as the danger from accident
alone should prohibit the practice except when properly installed and
cared for away from other sources of combustible gases.


ACETYLENE

In 1862 a chemist, Woehler, announced the discovery of the preparation of
acetylene gas from calcium carbide, which he had made by heating to a high
temperature a mixture of charcoal with an alloy of zinc and calcium. His
product would decompose water and yield the gas. For nearly thirty years
these substances were neglected, with the result that acetylene was
practically unknown, and up to 1892 an acetylene flame was seen by very few
persons and its possibilities were not dreamed of. With the development of
the modern electric furnace the possibility of calcium carbide as a
commercial product became known.

In the above year, Thomas L. Willson, an electrical engineer of Spray,
North Carolina, was experimenting in an attempt to prepare metallic
calcium, for which purpose he employed an electric furnace operating on a
mixture of lime and coal tar with about ninety-five horse power. The result
was a molten mass which became hard and brittle when cool. This apparently
useless product was discarded and thrown in a nearby stream, when, to the
astonishment of onlookers, a large volume of gas was immediately
liberated, which, when ignited, burned with a bright and smoky flame and
gave off quantities of soot. The solid material proved to be calcium
carbide and the gas acetylene.

Thus, through the incidental study of a by-product, and as the result of an