In 1846 Werner Siemens, of Berlin, discovered the non-conducting
properties of gutta-percha. He coated several miles of copper
wire with gutta-percha, and submerged it in the Rhine from Deutz
to Cologne. Electric communication was thus established beneath
the water from shore to shore. In 1850 a submarine cable was
laid across the English Channel from Dover to Cape Grisnez.
It consisted of a half-inch copper wire covered with nothing
but gutta-percha, and loaded with lead to keep it down. The
communication was perfect for a day, and then the wire refused
to act. The electrical engineers were unable to explain the
facts. At last the mystery was dissipated by a fisherman. A
French fisherman set his trawl off Cape Grisnez. When he hauled
it in, he picked up the submerged cable, from which he cut off
a piece. This piece he carried in triumph to Bologne, where
he exhibited it as a specimen of rare seaweed with its center
filled with gold. The ignorant man had mistaken the copper wire
for gold, but unwittingly he had served the electricians. They
saw from the accident that it was not sufficient perfectly to
insulate the cable, but that it must also be protected. In
1851 there was laid across the Channel a cable twenty-four
miles long, consisting of four copper wires, insulated by
gutta-percha, covered with tarred yarn, and protected by an
outer covering of galvanized iron wires. That submarine cable
proved a success, and ocean telegraphy became possible through
an accident which compelled invention.--_Youth’s Companion._
(1646)