's
pitch into work again.'"

Another interesting and amusing reminiscence of this period of
activity has been gathered from another of the family of experimenters:
"Sometimes, when Mr. Edison had been working long hours, he would
want to have a short sleep. It was one of the funniest things I ever
witnessed to see him crawl into an ordinary roll-top desk and curl up
and take a nap. If there was a sight that was still more funny, it was
to see him turn over on his other side, all the time remaining in the
desk. He would use several volumes of Watts's Dictionary of Chemistry
for a pillow, and we fellows used to say that he absorbed the contents
during his sleep, judging from the flow of new ideas he had on waking."

Such incidents as these serve merely to illustrate the lighter moments
that stand out in relief against the more sombre background of the
strenuous years, for, of all the absorbingly busy periods of Edison's
inventive life, the first five years of the storage-battery era was
one of the very busiest of them all. It was not that there remained any
basic principle to be discovered or simplified, for that had already
been done; but it was in the effort to carry these principles into
practice that there arose the numerous difficulties that at times seemed
insurmountable. But, according to another co-worker, "Edison seemed
pleased when he used to run up against a serious difficulty. It would
seem to stiffen his backbone and make him more prolific of new ideas.
For a time I thought I was foolish to imagine such a thing, but I could
never get away from the impression that he really appeared happy when
he ran up against a serious snag. That was in my green days, and I soon
learned that the failure of an experiment never discourages him unless
it is by reason of the carelessness of the man making it. Then Edison
gets disgusted. If it fails on its merits, he doesn't worry or fret
about it, but, on the contrary, regards it as a useful fact learned;
remains cheerful and tries something else. I have known him to reverse
an unsuccessful experiment and come out all right."

To follow Edison's trail in detail through the innumerable twists and
turns of his experimentation and research on the storage battery, during
the past ten years, would not be in keeping with the scope of this
narrative, nor would it serve any useful purpose. Besides, such details
would fill a big volume. The narrative, however, would not be complete
wi