y one I have met abroad. I
think that you have pursued an original course of experiments, and
discovered facts of more value to me than any that have been published
abroad.

Morse was too modest in saying that he could bring nothing of value to
Henry in his experiments, for, as we shall see from Henry's reply, the
latter had no knowledge at that time of the "relay," for bringing into
use a secondary battery when the line was to stretch over long distances.
This important discovery Morse had made several years before.

PRINCETON; May 6, 1889.

DEAR SIR,--Your favor of the 24th ult. came to Princeton during my
absence, which will account for the long delay of my answer. I am pleased
to learn that you fully sanction the loan which I obtained from Dr. Gale
of your wire, and I shall be happy if any of the results are found to
have a practical bearing on the electrical telegraph.

It will give me much pleasure to see you in Princeton after this week. My
engagements will not then interfere with our communications on the
subject of electricity. During this week I shall be almost constantly
engaged with a friend in some scientific labors which we are prosecuting
together.

I am acquainted with no fact which would lead me to suppose that the
project of the electro-magnetic telegraph is unpractical; on the
contrary, I believe that science is now ripe for the application, and
that there are no difficulties in the way but such as ingenuity and
enterprise may obviate. But what form of the apparatus, or what
application of the power will prove best, can, I believe, be only
determined by careful experiment. I can say, however, that, so far as I
am acquainted with the minutiae of your plan, I see no practical
difficulty in the way of its application for comparatively short
distances; but, if the length of the wire between the stations is great,
I think that some other modification will be found necessary in order to
develop a sufficient power at the farther end of the line.

I shall, however, be happy to converse freely with you on these points
when we meet. In the meantime I remain, with much respect

Yours, etc.,
JOSEPH HENRY.

I consider this letter alone a sufficient answer to those who claim that
Henry was the real inventor of the telegraph. He makes no such claim
himself.

In spite of the cares of various kinds which overwhelmed him during the
whole of his eventful life, Morse always found time to stretch out a
helpin