The Meeker herald., 1896-07-25
g. "A. SNOW eco.
MAKING AN. OCEAN GABLE.
\ Vast Amount Of wor;s before It Can
Re Laid In tho Ocean.
or. rArrsr o.nes. w..n,neron. D. G.


Be Laid In tho Ocean.
The making of an ocean cable is
:asls involving no small, amount of skill
md mechanical ingenuity, and it ii
something to the credit of the first cable
makers that their pattern has MOI
greatly changed in thirty years. When
the Commercial Cable company decided
to lay new Atlantic cable last year,
the work was intrusted to the iiria 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
6rst care of n cable manufacture 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 its standard OF conductivity
WILDE. Every strand and every coil OF
wire that goes into the cable is cx-
pected to reach u certain standard; and
to such 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-perchn insulation is
then applied in sheets prepared from
the raw material as it comes to hand
al NJn1.. NOR
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 tc
be submitted to galvonometer test, tc
ascertain whether the insulation is per
feet, or as neurly perfect as that very
elusive agent, electricity, will permit
That test having been satisfactorily
passed, q 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 ar
alternating current of 5000 volts, the
core is passed into the hands OF the
sheathers, whose care it is to surround
the copper and gutta-percha with
more substantial protective covering
before they are submitted to the rough
action of the sea. And now the weigh
and size of the cable become appreci
able. Already each mile length has il
1t some 500 pounds of pure copper ant
$40 pounds of pure gutta-percha. Owe
this is spun Of coat of jute yarn
weighing nearly 600 pounds to the mile
Then the cable is made the center OF
twisted sheath of steel wires of tn
stoutest kind, averaging more thai
1000 pounds to the mile. And finally
compound OF tar is laid over the whole
which brings its own weight of 50
pounds to the mile. After the tar
applied the cable is coiled and left
soak in tanks of water until such tim
as the cable ship shall be ready to la
It In its last resting place. Such cab
as this IL made at the rate of fifty
nfty-fve miles per twenty-four hours.