introduced and diligently supported in each succeeding Congress, but it
was not until the very closing hour of the expiring session of 1843 that
the necessary enactment was effected and the appropriation secured.

The plan of construction devised by Professor Morse for the experimental
line of telegraph to be erected between Washington and Baltimore, under
the Congressional appropriation, provided for placing insulated wires in
a lead pipe underground. This was to be accomplished by the use of a
specially devised plough of peculiar construction, to be drawn by a
powerful team, by which means the pipe containing the electric
conductors was to be automatically deposited in the earth. This
apparatus was entirely successful in operation, and the pipe was thus
buried to the complete satisfaction of all concerned, at a cost very
much lower than the work could have been accomplished in any other
manner. Two wires were to be used to form a complete metallic circuit,
for at that time it was not known, as was shortly afterward discovered,
that the earth could be used to form one-half of the circuit. For
purposes of insulation the wires were neatly covered with cotton-yarn
and then saturated in a bath of hot gum-shellac, but this treatment
proved defective in insulating properties, for when ten miles of line
had been completed the wires were found to be wholly useless for
electric conduction.

No mode had been devised for the treatment of india-rubber to make it
available for purposes of insulation, and gutta-percha was wholly
unknown as an article of use or commerce in this country. Twenty-three
thousand dollars of the Government appropriation had been expended, and
the work thus far accomplished was an acknowledged failure. Only seven
thousand dollars of the available fund remained unexpended, and this was
regarded as inadequate to complete the undertaking under any other plan.