d
hardihood to set at naught the confirmed opinions of the world,
voiced by those generally acknowledged to be the best exponents of the
art--experiments carried on amid a storm of jeers and derision, almost
as contemptuous as if the search were for the discovery of perpetual
motion. In this we see the man foreshadowed by the boy who, when he
obtained his books on chemistry or physics, did not accept any statement
of fact or experiment therein, but worked out every one of them himself
to ascertain whether or not they were true.

Although this brings the reader up to the year 1879, one must turn back
two years and accompany Edison in his first attack on the electric-light
problem. In 1877 he sold his telephone invention (the carbon
transmitter) to the Western Union Telegraph Company, which had
previously come into possession also of his quadruplex inventions,
as already related. He was still busily engaged on the telephone,
on acoustic electrical transmission, sextuplex telegraphs, duplex
telegraphs, miscellaneous carbon articles, and other inventions of a
minor nature. During the whole of the previous year and until late in
the summer of 1877, he had been working with characteristic energy and
enthusiasm on the telephone; and, in developing this invention to a
successful issue, had preferred the use of carbon and had employed it in
numerous forms, especially in the form of carbonized paper.

Eighteen hundred and seventy-seven in Edison's laboratory was a
veritable carbon year, for it was carbon in some shape or form for
interpolation in electric circuits of various kinds that occupied the
thoughts of the whole force from morning to night. It is not surprising,
therefore, that in September of that year, when Edison turned his
thoughts actively toward electric lighting by incandescence, his early
experiments should be in the line of carbon as an illuminant. His
originality of method was displayed at the very outset, for one of the
first experiments was the bringing to incandescence of a strip of carbon
in the open air to ascertain merely how much current was required.
This conductor was a strip of carbonized paper about an inch long,
one-sixteenth of an inch broad, and six or seven one-thousandths of an
inch thick, the ends of which were secured to clamps that formed the
poles of a battery. The carbon was lighted up to incandescence, and, of
course, oxidized and disintegrated immediately. Within a few days this
was foll