made a
start, and being entirely new was without precedent upon which to base
any such statement, but, as a matter of fact, the records of the lamp
factory show that in 1896 its daily output of lamps was actually about
forty thousand.

The other instance referred to occurred shortly after the Edison Machine
Works was moved up to Schenectady, in 1886. One day, when he was at the
works, Edison sat down and wrote on a sheet of paper fifteen separate
predictions of the growth and future of the electrical business.
Notwithstanding the fact that the industry was then in an immature
state, and that the great boom did not set in until a few years
afterward, twelve of these predictions have been fully verified by the
enormous growth and development in all branches of the art.

What the explanation of this gift, power, or intuition may be, is
perhaps better left to the psychologist to speculate upon. If one were
to ask Edison, he would probably say, "Hard work, not too much sleep,
and free use of the imagination." Whether or not it would be possible
for the average mortal to arrive at such perfection of "guessing" by
faithfully following this formula, even reinforced by the Edison
recipe for stimulating a slow imagination with pastry, is open for
demonstration.

Somewhat allied to this curious faculty is another no less remarkable,
and that is, the ability to point out instantly an error in a mass of
reported experimental results. While many instances could be definitely
named, a typical one, related by Mr. J. D. Flack, formerly master
mechanic at the lamp factory, may be quoted: "During the many years
of lamp experimentation, batches of lamps were sent to the photometer
department for test, and Edison would examine the tabulated test sheets.
He ran over every item of the tabulations rapidly, and, apparently
without any calculation whatever, would check off errors as fast as he
came to them, saying: 'You have made a mistake; try this one over.'
In every case the second test proved that he was right. This wonderful
aptitude for infallibly locating an error without an instant's
hesitation for mental calculation, has always appealed to me very
forcibly."

The ability to detect errors quickly in a series of experiments is one
of the things that has enabled Edison to accomplish such a vast amount
of work as the records show. Examples of the minuteness of detail into
which his researches extend have already been mentioned, and as