The news and herald. (Winnsboro, S.C.) 1877-1900, 1895-04-04
MAKING An OCEAN CABLE
4 Vast Amount Of Work Before Is Cas
Be Laid In the Ocean.

Be Laid In tho ocean,
The mixing Of an ocean cable Is
ask involving no small amount Of skill
and mechanical ingenuity, and 1t Is
something to the credit Of the first cable
makers that their pattern has not
greatly changed in thirty years. When
the, Commercial Gable Company de
.ided to lay a new Atlantic cable las'
rear, the work was intrusted to the
Irm Of Siemens Brothers, Of Woolwtcn,
London. As this firm has constructed
10 less than eight out Of the eleven
.ables now linking Great Britain ana
he United States, says the New Science
Review, it's methods of manufacture
nay be watched as typical OF the best.
The first care Of a cable manufacturer
8 to secure the very best materials.
The copper wire, which forms the heart
ind essential part Of the cable, must &c
II the purest metal, since the purer the
metal the higher its standard OF COLI
luctivity will be. Every strand and
every coil Of wire that goes fato tho
cable is expected to reach q certain
standard; and to such degree Of excel
ence Is the making Of copper wire for
electrical purposes brought nowadays
that the material submitted is more
frequently above that standard than BE-
low.
The single wires having passed tho
est for purity and conducting power,
eleven similar strands are taken and
spun into slender rope in lengths OF
,ne mile. Guttapercha insulation Is
hen applied In sheets prepared from
he raw material as it comes to hand
from Singapore and other Malay ports.
These sheets are wrapped by expe-
:ienced hands so firmly and smoothly
round the wire that not an air bubble
AN remain between the copper and Its
nsulator. The "core" Is then ready 10
be submitted to a galyanometer test, as
ascertain whether the insulation is per-
,ect or as nearly perfect as that very
elusive agent, electricity, will permit.
That test having been satisfactorily
passed, a workman, whose sole busl-
less it is to attend to the joining OF the
engths Of cable, splices the ends Of the
nile lengths. Again the insulation test
applied. The galvanometer indicat-
ng no Very appreciable loss Of electrici-
y, even under the strain Of an alternat-
ng current Of 5000 volts, the core is
passed into the hands Of the sheathers,
whose care it is to surround the copper
md guttapercha with more substan-
:ial protective covering before they are
submitted to the rough action Of the
sea. And now the weight and size OF
he cable become appreciable. Already
each mile length has in 1t some 800
pounds Of pure copper and $40 pounds
If pure guttapercha- Over this is spun
coat of jute yarn weighing nearly $40
pounds to the mile. Then the cable
S made the center Of a twisted sheath
If steel wires Of the stoutest kind, aver.
aging more than 1000 pounds to the
enile. And finally compound of tar
s laid over the whole, which brings its
,wn weight of 800 pounds to the mile.
After the tar is applied the cable is
.oiled and left to soak in tanks Of water
Until such time as the cable ship shall
,e ready to lay it in its last resting
place. Such a cable as this is made ut
he rate Of fifty to ifty-fve miles per
sWenty-fodr hours.