in impressions left upon
me after knowing Mr. Edison for many years is the marvellous accuracy of
his guesses. He will see the general nature of a result long before it
can be reached by mathematical calculation. His greatness was always to
be clearly seen when difficulties arose. They always made him cheerful,
and started him thinking; and very soon would come a line of suggestions
which would not end until the difficulty was met and overcome, or found
insurmountable. I have often felt that Mr. Edison got himself purposely
into trouble by premature publications and otherwise, so that he would
have a full incentive to get himself out of the trouble."

This chapter may well end with a statement from Mr. Jehl, shrewd and
observant, as a participator in all the early work of the development of
the Edison lighting system: "Those who were gathered around him in the
old Menlo Park laboratory enjoyed his confidence, and he theirs. Nor was
this confidence ever abused. He was respected with a respect which only
great men can obtain, and he never showed by any word or act that he was
their employer in a sense that would hurt the feelings, as is often the
case in the ordinary course of business life. He conversed, argued, and
disputed with us all as if he were a colleague on the same footing. It
was his winning ways and manners that attached us all so loyally to his
side, and made us ever ready with a boundless devotion to execute any
request or desire." Thus does a great magnet, run through a heap of sand
and filings, exert its lines of force and attract irresistibly to itself
the iron and steel particles that are its affinity, and having sifted
them out, leaving the useless dust behind, hold them to itself with
responsive tenacity.

CHAPTER XIII

A WORLD-HUNT FOR FILAMENT MATERIAL

IN writing about the old experimenting days at Menlo Park, Mr. F. R.
Upton says: "Edison's day is twenty-four hours long, for he has always
worked whenever there was anything to do, whether day or night, and
carried a force of night workers, so that his experiments could go on
continually. If he wanted material, he always made it a principle to
have it at once, and never hesitated to use special messengers to get
it. I remember in the early days of the electric light he wanted a
mercury pump for exhausting the lamps. He sent me to Princeton to get
it. I got back to Metuchen late in the day, and had to carry the pump
over to the laboratory on m