a difference of opinion as to the comparative value
of a new discovery and a new invention, and the difference between these
terms should be clearly apprehended. While they are to a certain extent
interchangeable, the word "discovery" in science is usually applied to
the first enunciation of some property of nature till then unrecognized;
"invention," on the other hand, is the application of this property to
the uses of mankind. Sometimes discovery and invention are combined in
the same individual, but often the discoverer is satisfied with the fame
arising from having called attention to something new, and leaves to
others the practical application of his discovery. Scientists will always
claim that a new discovery, which marks an advance in knowledge in their
chosen field, is of paramount importance; while the world at large is
more grateful to the man who, by combining the discoveries of others and
adding the culminating link, confers a tangible blessing upon humanity.

Morse was completely possessed by this new idea. He worked over it that
day and far into the night. His vivid imagination leaped into the future,
brushing aside all obstacles, and he realized that here in his hands was
an instrument capable of working inconceivable good. He recalled the days
and weeks of anxiety when he was hungry for news of his loved ones; he
foresaw that in affairs of state and of commerce rapid communication
might mean the avoidance of war or the saving of a fortune; that, in
affairs nearer to the heart of the people, it might bring a husband to
the bedside of a dying wife, or save the life of a beloved child;
apprehend the fleeing criminal, or commute the sentence of an innocent
man. His great ambition had always been to work some good for his
fellow-men, and here was a means of bestowing upon them an inestimable
boon.

After several days of intense application he disclosed his plan to Mr.
Rives and to others. Objections were raised, but he was ready with a
solution. While the idea appeared to his fellow-passengers as chimerical,
yet, as we have seen, his earnestness made so deep an impression that
when, several years afterwards, he exhibited to some of them a completed
model, they, like Captain Pell, instantly recognized it as embodying the
principles explained to them on the ship.

Without going deeply into the scientific history of the successive steps
which led up to the invention of the telegraph, I shall quote a few
sent