as. The book is numbered 184, falls into
the period now dealt with, and runs along casually with items spread
out over two or three years. All these notes refer specifically to
"Electricity vs. Gas as General Illuminants," and cover an astounding
range of inquiry and comment. One of the very first notes tells the
whole story: "Object, Edison to effect exact imitation of all done by
gas, so as to replace lighting by gas by lighting by electricity. To
improve the illumination to such an extent as to meet all requirements
of natural, artificial, and commercial conditions." A large programme,
but fully executed! The notes, it will be understood, are all in
Edison's handwriting. They go on to observe that "a general system of
distribution is the only possible means of economical illumination," and
they dismiss isolated-plant lighting as in mills and factories as of so
little importance to the public--"we shall leave the consideration of
this out of this book." The shrewd prophecy is made that gas will be
manufactured less for lighting, as the result of electrical competition,
and more and more for heating, etc., thus enlarging its market and
increasing its income. Comment is made on kerosene and its cost, and all
kinds of general statistics are jotted down as desirable. Data are to be
obtained on lamp and dynamo efficiency, and "Another review of the whole
thing as worked out upon pure science principles by Rowland, Young,
Trowbridge; also Rowland on the possibilities and probabilities of
cheaper production by better manufacture--higher incandescence without
decrease of life of lamps." Notes are also made on meters and motors.
"It doesn't matter if electricity is used for light or for power";
while small motors, it is observed, can be used night or day, and small
steam-engines are inconvenient. Again the shrewd comment: "Generally
poorest district for light, best for power, thus evening up whole
city--the effect of this on investment."

It is pointed out that "Previous inventions failed--necessities
for commercial success and accomplishment by Edison. Edison's great
effort--not to make a large light or a blinding light, but a small light
having the mildness of gas." Curves are then called for of iron
and copper investment--also energy line--curves of candle-power and
electromotive force; curves on motors; graphic representation of
the consumption of gas January to December; tables and formulae;
representations graphically of