s and then written now shows the paper eaten out by
the acid used, although covered with glass for many years. Mr. Edison
does not remember that he ever recurred to this very interesting test.

He was, however, ready for anything new or novel, and no record can ever
be made or presented that would do justice to a tithe of the thoughts
and fancies daily and hourly put upon the rack. The famous note-books,
to which reference will be made later, were not begun as a regular
series, as it was only the profusion of these ideas that suggested
the vital value of such systematic registration. Then as now, the
propositions brought to Edison ranged over every conceivable subject,
but the years have taught him caution in grappling with them. He tells
an amusing story of one dilemma into which his good-nature led him at
this period: "At Menlo Park one day, a farmer came in and asked if I
knew any way to kill potato-bugs. He had twenty acres of potatoes, and
the vines were being destroyed. I sent men out and culled two quarts
of bugs, and tried every chemical I had to destroy them. Bisulphide of
carbon was found to do it instantly. I got a drum and went over to the
potato farm and sprinkled it on the vines with a pot. Every bug dropped
dead. The next morning the farmer came in very excited and reported
that the stuff had killed the vines as well. I had to pay $300 for not
experimenting properly."

During this year, 1878, the phonograph made its way also to Europe,
and various sums of money were paid there to secure the rights to its
manufacture and exploitation. In England, for example, the Microscopic
Company paid $7500 down and agreed to a royalty, while arrangements were
effected also in France, Russia, and other countries. In every instance,
as in this country, the commercial development had to wait several
years, for in the mean time another great art had been brought into
existence, demanding exclusive attention and exhaustive toil. And when
the work was done the reward was a new heaven and a new earth--in the
art of illumination.

CHAPTER XI

THE INVENTION OF THE INCANDESCENT LAMP

IT is possible to imagine a time to come when the hours of work and rest
will once more be regulated by the sun. But the course of civilization
has been marked by an artificial lengthening of the day, and by a
constant striving after more perfect means of illumination. Why mankind
should sleep through several hours of sunlight in the mornin