closed in unison with the main circuit, the receiver can be operated.
It was the relay which made it possible to extend telegraph lines to
a considerable distance. It is not altogether clear whether Morse
adopted Henry's relay or devised it for himself. It is believed,
however, that Professor Henry explained the relay to Professor Gale,
who in turn placed it before his partner, Morse.

By 1837 Morse had completed a model, had improved his apparatus, had
secured stronger batteries and longer wires, and mastered the use
of the relay. It was in this year that the House of Representatives
ordered the Secretary of the Treasury to investigate the feasibility
of establishing a system of telegraphs. This action urged Morse to
complete his apparatus and place it before the Government. He was
still handicapped by lack of money, lack of scientific knowledge, and
the difficulty of securing necessary materials and devices. To-day the
experimenter may buy wire, springs, insulators, batteries, and almost
anything that might be useful. Morse, with scanty funds and limited
time, had to search for his materials and puzzle out the way to make
each part for himself with such crude tools as he had available. Need
we wonder that his progress was slow? Instead we should wonder that,
despite all discouragements and handicaps, he clung to his great idea
and labored on.

But assistance was to come to him in this same eventful year of 1837,
and that quite unexpectedly. On a Saturday in September a young man
named Alfred Vail wandered into Professor Gale's laboratory. Morse
was there engaged in exhibiting his model to an English professor then
visiting in New York. The youth was deeply impressed with what he saw.
He realized that here were possibilities of an instrument that would
be of untold service to mankind. Asking Professor Morse whether he