The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1895-03-09
MAKING AN OCEAN cAaLE.
Vast Amount of work before IL Can
Be Laid IN the Ocean.

Be Laid I'm the Ocean
The making Of an ocean cable Is n
task involving no small, amount of skill
and mechanical ingenuity, and II Ii
something 90 the credit of the first cable
makers that their pattern has not
greatly changed In thirty years. When
the Commercial Cable company decided
TO lay new Atlantic cable last year,
the work was intrusted 10 the firm OF
siemens Brothers, of Woolwich, Lon
don. AS this firm has constructed no
less than eight out OF the eleven cables
now linking Great Britain and the
United States, says the new Science Re-
view, its method of manufacture may
be watched as typical OF the best. The
first care of a cable manufactures Is to
secure the very best materials. The
copper wire, which forms the heart and
essential part of the cable, must be of the
purest metal, since the purer the metal
the higher it's standard OF conductivity
WILDE. Every strand and every coil OF
wire that goes into the cable Is ex-
pected 10 reach certain standard; and
TO such q degree of excellence Is the
making OF copper wire for electrical
purposes brought nowadays that the
material submitted Is more frequently
above that standard than below.
The single wires having passed the
test for purity and conducting power,
eleven similar strands are taken and
spun into slender rope in lengths of
one mile. Gutta-percha insulation Is
then applied in sheets prepared from
the raw material as IL comes TO hand
from Singapore and other Malay ports.
These sheets are wrapped by ex-
perienced hands so firmly and smoothly
round the wire that not an air bubble
can remain between the copper and its
insulator. The "core" Is then ready TO
be submitted TO galvonometer test, TO
ascertain whether the insulation Is per-
feet, or as nearly perfect as that very
elusive agent, electricity, will permit.
That test having been satisfactorily
passed, a workman, whose sole bust
ness is TO attend TO the joining Of the
lengths of cable, spices the ends of the
mile lengths. Again the insulation
test is applied. The galvanometer in
dicating no very appreciable loss of
electricity, even under the strain OF an
alternating current of 5000 volts, the
core is passed into the hands of the
sheathcrs, whose care IL is 10 surround
the copper and gutta-percha with a
more substantial protective covering
before they are submitted 10 the rough
action of the sea. And now the weight
and size Of the cable become appreci-
able. Already each mile length has in
II some 500 pounds Of pure copper and
$40 pounds of pure gutta-percha. Over
this is n spun of coat Of jute yarn
weighing nearly 600 pounds 10 the mile.
Then the cable is made the center Of a
twisted sheath of steel wires OF the
stoutest kind, averaging more than
1000 pounds 20 the mile. And finally a
compound of tar is laid over the whole,
which brings its own weight of 500
pounds TO the mile. After the tar Is
applied the cable Is coilcd and left To
soak in tanks of water until such time
as the cable ship shall be ready to lay
it in its last resting place. Such cable
as this is made at the rate of fifty 10
flfty-fivc miles per twenty-four hours.