ned up an entirely new and
tremendously important art--the art of incandescent electric lighting.
This statement cannot be successfully controverted, for it has been
abundantly verified after many years of costly litigation. If further
proof were desired, it is only necessary to point to the fact that,
after thirty years of most strenuous and practical application in the
art by the keenest intellects of the world, every incandescent lamp
that has ever since been made, including those of modern days, is
still dependent upon the employment of the essentials disclosed in the
above-named patent--namely, a filament of high resistance enclosed in
a sealed glass globe exhausted of air, with conducting wires passing
through the glass.

An incandescent lamp is such a simple-appearing article--merely a
filament sealed into a glass globe--that its intrinsic relation to the
art of electric lighting is far from being apparent at sight. To the lay
mind it would seem that this must have been THE obvious device to make
in order to obtain electric light by incandescence of carbon or
other material. But the reader has already learned from the preceding
narrative that prior to its invention by Edison such a device was NOT
obvious, even to the most highly trained experts of the world at that
period; indeed, it was so far from being obvious that, for some time
after he had completed practical lamps and was actually lighting them up
twenty-four hours a day, such a device and such a result were declared
by these same experts to be an utter impossibility. For a short while
the world outside of Menlo Park held Edison's claims in derision.
His lamp was pronounced a fake, a myth, possibly a momentary success
magnified to the dignity of a permanent device by an overenthusiastic
inventor.

Such criticism, however, did not disturb Edison. He KNEW that he had
reached the goal. Long ago, by a close process of reasoning, he had
clearly seen that the only road to it was through the path he had
travelled, and which was now embodied in the philosophy of his
incandescent lamp--namely, a filament, or carbon, of high resistance and
small radiating surface, sealed into a glass globe exhausted of air to a
high degree of vacuum. In originally committing himself to this line
of investigation he was well aware that he was going in a direction
diametrically opposite to that followed by previous investigators. Their
efforts had been confined to low-resistance bur