experiments and tests on carbons, lamps, dynamos,
armatures, commutators, windings, systems, regulators, sockets,
vacuum-pumps, and the thousand and one details relating to the subject
in general, originated by Edison, and methodically and systematically
carried on under his general direction, would fill a great many pages
here, and even then would serve only to convey a confused impression of
ceaseless probing.

It is possible only to a broad, comprehensive mind well stored with
knowledge, and backed with resistless, boundless energy, that such a
diversified series of experiments and investigations could be carried
on simultaneously and assimilated, even though they should relate to a
class of phenomena already understood and well defined. But if we pause
to consider that the commercial subdivision of the electric current
(which was virtually an invention made to order) involved the solution
of problems so unprecedented that even they themselves had to be
created, we cannot but conclude that the afflatus of innate genius
played an important part in the unique methods of investigation
instituted by Edison at that and other times.

The idea of attributing great successes to "genius" has always been
repudiated by Edison, as evidenced by his historic remark that "Genius
is 1 per cent. inspiration and 99 per cent. perspiration." Again, in a
conversation many years ago at the laboratory between Edison, Batchelor,
and E. H. Johnson, the latter made allusion to Edison's genius as
evidenced by some of his achievements, when Edison replied:

"Stuff! I tell you genius is hard work, stick-to-it-iveness, and common
sense."

"Yes," said Johnson, "I admit there is all that to it, but there's still
more. Batch and I have those qualifications, but although we knew quite
a lot about telephones, and worked hard, we couldn't invent a brand-new
non-infringing telephone receiver as you did when Gouraud cabled for
one. Then, how about the subdivision of the electric light?"

"Electric current," corrected Edison.

"True," continued Johnson; "you were the one to make that very
distinction. The scientific world had been working hard on subdivision
for years, using what appeared to be common sense. Results worse than
nil. Then you come along, and about the first thing you do, after
looking the ground over, is to start off in the opposite direction,
which subsequently proves to be the only possible way to reach the goal.
It seems to me th