current, in all elements save its danger, was and is ideal. Its thin
wires can be carried cheaply over vast areas, and at each local point
of consumption the transformer of size exactly proportioned to its
local task takes the high-voltage transmission current and lowers its
potential at a ratio of 20 or 40 to 1, for use in distribution and
consumption circuits. This evolution has been quite distinct, with its
own inventors like Gaulard and Gibbs and Stanley, but came subsequent
to the work of supplying small, dense areas of population; the art thus
growing from within, and using each new gain as a means for further
achievement.

Nor was the effect of such great advances as those made by Edison
limited to the electrical field. Every department of mechanics was
stimulated and benefited to an extraordinary degree. Copper for the
circuits was more highly refined than ever before to secure the best
conductivity, and purity was insisted on in every kind of insulation.
Edison was intolerant of sham and shoddy, and nothing would satisfy him
that could not stand cross-examination by microscope, test-tube, and
galvanometer. It was, perhaps, the steam-engine on which the deepest
imprint for good was made, referred to already in the remarks of Mr.
F. J. Sprague in the preceding chapter, but best illustrated in the
perfection of the modern high-speed engine of the Armington & Sims type.
Unless he could secure an engine of smoother running and more exactly
governed and regulated than those available for his dynamo and lamp,
Edison realized that he would find it almost impossible to give a steady
light. He did not want his customers to count the heart-beats of the
engine in the flicker of the lamp. Not a single engine was even within
gunshot of the standard thus set up, but the emergency called forth its
man in Gardiner C. Sims, a talented draughtsman and designer who
had been engaged in locomotive construction and in the engineering
department of the United States Navy. He may be quoted as to what
happened: "The deep interest, financial and moral, and friendly backing
I received from Mr. Edison, together with valuable suggestions, enabled
me to bring out the engine; as I was quite alone in the world--poor--I
had found a friend who knew what he wanted and explained it clearly. Mr.
Edison was a leader far ahead of the time. He compelled the design of
the successful engine.

"Our first engine compelled the inventing and making of a s