me from the other end of the line."

The author of this letter points out, besides, the possibility of
keeping, in the first place, all the springs in contact with the
battery, and, consequently, all the letters attracted, and of indicating
each letter by removing its wire from the battery, and consequently
making it fall. He even proposed to substitute bells of different sounds
for the balls, and to produce electric sparks upon them. The sound
produced by the spark would vary according to the bell, and the letters
might thus be heard.

Nothing, however, in this document authorizes the belief that Charles
Marshall ever realized his idea, so we must proceed to 1774 to find
Lesage, of Geneva, constructing a telegraph that was based upon the
principle indicated twenty years before in the letter of Renfrew.

The apparatus that Lesage devised (Fig. 1) was composed of 24 wires
insulated from one another by a non conducting material. Each of these
wires corresponded to a small pith ball suspended by a thread. On
putting an electric machine in communication with such or such a one of
these wires, the ball of the corresponding electrometer was repelled,
and the motion signaled the letter that it was desired to transmit. Not
content with having realized an electric telegraph upon a small scale,
Lesage thought of applying it to longer distances.

"Let us conceive," said he in a letter written June 22, 1782, to Mr.
Prevost, of Geneva, "a subterranean pipe of enameled clay, whose cavity
at about every six feet is separated by partitions of the same material,
or of glass, containing twenty-four apertures in order to give passage
to as many brass wires as these diaphragms are to sustain and keep