each other hammer and tongs, the
arguments TO HIM being carried on at the very top of one's voice to
enable him to hear, and FROM HIM being equally loud in the excitement
of the discussion, he has often said: "I see now that my position was
absolutely rotten."

Obviously, however, all of these personal characteristics have nothing
to do with Edison's position in the world of affairs. They show him
to be a plain, easy-going, placid American, with no sense of
self-importance, and ready at all times to have his mind turned into a
lighter channel. In private life they show him to be a good citizen, a
good family man, absolutely moral, temperate in all things, and of great
charitableness to all mankind. But what of his position in the age
in which he lives? Where does he rank in the mountain range of great
Americans?

It is believed that from the other chapters of this book the reader can
formulate his own answer to the question.

INTRODUCTION TO THE APPENDIX

THE reader who has followed the foregoing narrative may feel that
inasmuch as it is intended to be an historical document, an appropriate
addendum thereto would be a digest of all the inventions of Edison. The
desirability of such a digest is not to be denied, but as there are some
twenty-five hundred or more inventions to be considered (including those
covered by caveats), the task of its preparation would be stupendous.
Besides, the resultant data would extend this book into several
additional volumes, thereby rendering it of value chiefly to the
technical student, but taking it beyond the bounds of biography.

We should, however, deem our presentation of Mr. Edison's work to
be imperfectly executed if we neglected to include an intelligible
exposition of the broader theoretical principles of his more important
inventions. In the following Appendix we have therefore endeavored
to present a few brief statements regarding Mr. Edison's principal
inventions, classified as to subject-matter and explained in language
as free from technicalities as is possible. No attempt has been made to
conform with strictly scientific terminology, but, for the benefit of
the general reader, well-understood conventional expressions, such as
"flow of current," etc., have been employed. It should be borne in mind
that each of the following items has been treated as a whole or class,
generally speaking, and not as a digest of all the individual patents
relating to it. Any one wh