telephone sets for
communication with their confederates off the stage.
The idea of encircling a floating needle with the alphabet was
developed into the sympathetic telegraph of the sixteenth century,
which was based on a curious error. It was supposed that needles which
had been touched by the same lodestone were sympathetic, and that if
both were free to move one would imitate the movements of another,
though they were at a distance. Thus, if one needle were attracted
toward one letter after the other, and the second similarly mounted
should follow its movements, a message might readily be spelled out.
Of course the second needle would not follow the movements of the
first, and so the sympathetic telegraph never worked, but much effort
was expended upon it.
In the mean time others had learned that many substances besides
amber, on being rubbed, possessed magnetic properties. Machines by
which electricity could be produced in greater quantities by friction
were produced and something was learned of conductors.
Benjamin Franklin sent aloft his historic kite and found that
electricity came down the silken cord. He demonstrated that frictional
and atmospheric electricity are the same. Franklin and others sent the
electric charge along a wire, but it did not occur to them to endeavor
to apply this to sending messages.
Credit for the first suggestion of an electric telegraph must be given
to an unknown writer of the middle eighteenth century. In the _Scots
Magazine_ for February 17, 1755, there appeared an article signed
simply, "C.M.," which suggested an electric telegraph. The writer's
idea was to lay an insulated wire for each letter of the alphabet.
The wires could be charged from an electrical machine in any desired
order, and at the receiving end would attract disks of paper marked
with the letter which that wire represented, and so any message could
be spelled out. The identity of "C.M." has never been established, but
he was probably Charles Morrison, a Scotch surgeon with a reputation
for electrical experimentation, who later emigrated to Virginia. Of
course "C.M.'s" telegraph was not practical, because of the many wires
required, but it proved to be a fertile suggestion which was followed
by many other thinkers. One experimenter after another added an
improvement or devised a new application.
A French scientist devised a telegraph which it is suspected might
have been practical, but he kept his device
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