replied that the current was apparently instantaneous. Morse, who
probably remembered his old lessons in the subject, now remarked that if
the presence of the electricity could be rendered visible at any point
of the circuit he saw no reason why intelligence might not be sent by
this means.

The idea became rooted in his mind, and engrossed his thoughts. Until
far into the night he paced the deck discussing the matter with Dr.
Jackson, and pondering it in solitude. Ways of rendering the electricity
sensible at the far end of the line were considered. The spark might
pierce a band of travelling paper, as Professor Day had mentioned years
before; it might decompose a chemical solution, and leave a stain to
mark its passage, as tried by Mr. Dyar in 1827; Or it could excite an
electro-magnet, which, by attracting a piece of soft iron, would
inscribe the passage with a pen or pencil. The signals could be made by
very short currents or jets of electricity, according to a settled code.
Thus a certain number of jets could represent a corresponding numeral,
and the numeral would, in its turn, represent a word in the language. To
decipher the message, a special code-book or dictionary would be
required. In order to transmit the currents through the line, he devised
a mechanical sender, in which the circuit would be interrupted by a
series of types carried on a port-rule or composing-stick, which
travelled at a uniform speed. Each type would have a certain number of
teeth or projections on its upper face, and as it was passed through a
gap in the circuit the teeth would make or break the current. At the
other end of the line the currents thus transmitted would excite the
electro-magnet, actuate the pencil, and draw a zig-zag line on the
paper, every angle being a distinct signal, and the groups of signals
representing a word in the code.