The times., 1898-10-15
OCEAN CABLES.
How the Lines Are Insulated With
Gutta-Percha.

One-half Of the world has grown ac-
customed to talking with the other half
by means OF the submarine cable II is
no longer a matter for wonderment or
even enthusiasm, but mere matter of
course. Yet only about generation and
half in time has elapsed since the first
of these wonders was worked Today
hundreds of thousands of miles of strong
wires lie on the bottom OF the ocean
connecting all lands with all others With
the extension of the empire of this coun-
try comes the desire TO connect the far
away colonies with the continent by this
means, so that it is only a matter of
months when Hawaii, the Ladrones and
Philippines will be connected by way of
the Pacific.
Men are living today who witnessed
and participated in the enthusiasm
which agitated the people when the first
message was flashed between New York
and Great Britain Three years ago one
group OF Chicagoans in one room in a
building in this city sent a message 10
another in another room not twenty feet
distant. The message went all around
the earth and was received on the enun-
ciator in an incredibly short time with
all the registration marks to show the
thousands of miles 1t had covered. The
feat caused less comment than did the
receipt of the original message between
the two big Anglo-Saxon nations some
forty years ago.
Out of the necessities of the world for
rapid communication has grown another
occupation Now the world could not do
business minus the cable. Hence the 130-
000 miles of cables in use, to say nothing
of those projected, require men specially
trained for the work; ships specially fit
ted for handling the long coils and crews
ready to invade any section of the earth
Repairs must be made constantly, so that
these men have plenty of labor during the
whole year. The process of preparing a
cable line from the making of the cable
itself TO the opening of the new line is
one of the interesting things of the pres
ent day.
Submarine cables must lie under the salt
sea, hence they must be specially prepar-
ed to resist the encroachments of the big
bodies of water. Water fresh or salt
has a great liking for electricity. so the
cable must be well insulated or 1t refuses
to work. These cables are made in three
parts. The inner part is the transmitting
wire which carries the current from point
to point. II is of copper stranded with six
finer copper wires. Around this cable of
copper sheath of gutta-percha is fitted
in three sections and the whole enveloped
in an outer covering of strong steel wires
to give the whole the strength to resist
the fraying of the constantly moving sea
Gutta-percha is not absolutely a nom
conductor of electricity. but it approaches
this desirable state of affairs nearly as
TO be of sufficient service In retaining the
current In the central cable. An eminent
civil engineer has declared its conductivity
to stand in the same relation to copper as
the ratio of a body moving through l foot
In 500 years is to the velocity of light.
This is a strong saying, and he who wishes
can figure it out to his satisfaction or
mental dizziness, as the case may be.
But the gum is all right. for thirty-five or
forty years experience is better than all
the equations man can devise.