The Sun.
London, England, 1858-10-09 00:00:00

SUBMARINE TELEGRAPHS IN
AUSTRALIA.

Mr. W. T. Henley, the submarine cable maker,
of Greenwich, is just on the point, of completing a
cable ordered from him by the Colonial Govern-
ment of Victoria. It is intended to be laid from
the city of Victoria, across Bass's Straits to Laun-
ceston in Tasmania, and will be in three sections,
the first cable being from Victoria to Cape Wick-
ham, on King Island, whence communication will
be continued by a land line to the opposite extre-
mity of that island ; the second from the latter
point to Hunter Island, across which also a land
will be continued ; and the third from Hunter
Island to Launceston, in Tasmania. The total
length of the cable is 250 miles. The conductor is
a solid copper wire of No. 16 gauge, double covered,
up
.to No. 1 size, with gutta percha ; the ex-
terior of the gutta percha is sewed with Russian
hemp, saturated with a mixture of Stockholm
tar, linseed oil, and Russian tallow. The
outer covering spun by Mr. Henley around this
sewing of hemp consists of 10 solid iron wires, of
No. 8 size. The " lay" of these iron wires is right
handed, and the length of each " lay" is 15 inches.
The weight of the cable is two tons to the statute
mile. The engineers who have superintended its
construction are Mr. Latimer Clarke, the engineer
of the Electric and International Company of Eng-
land, and Mr. W. H. Butcher, of Hobart-town.
The latter gentleman will have charge of the sub-
mersion of the cable. During the whole period of
manufacture every flake has been daily submerged
as it was completed, and tested with an upright
galvanometer capable of showing 30 degrees of de-
flection under the influence of a pair of battery
plates. Under this test we are informed that Mr.
Henley's cable does not evince a single degree of
loss of insulation. The shipment will commence
this day.
A NEW SUBMARINE CABLE.

Another invention is in the field. Mr. Rogers,
well known as the inventor of the linendraper's
blocking and measuring machine, has furnished the
Atlantic Telegraph Company with specimens of a
cable which appears to us to combine all the requi-
sites necessary for securing the grand object on
which the eyes of the whole world are fixed. Mr.
Rogers's cable is made of flax or hemp, spun into
fine threads and formed into what is called a spin-
net-plait, which is laid longitudinally—a new
feature in telegraphy—and in sufficient numbers to
cover the wire, the whole being bound tightly to-
gether. To give additional strength, when neces-
sary, a plaited cord is twisted round the cable,
which enables it to hold a larger quantity of water-
proofing material, put on to render the rope
thoroughly impervious to the water. Any number
of wires can be insulated in the gutta percha; and
whatever the strain upon the cable, the wires will
be the last to receive it. There is also another ad-
vantage in Mr. Rogers' cable, arising from its com-
parative lightness and elasticity—it is not likely to
" kink," as there is neither twist nor turn in its
entire construction, which is the case with all spiral
ropes, so that the first strain upon them
is almost sure to break the centre core. The
material used by Mr. Rogers for waterproofing is
mainly composed of oil, rosin, and tallow, which
will not only preserve it many years under water,
but leaves it quite supple and easy to be laid down.
The specimen of cable examined consists of a single
wire, insulated in gutta percha, and is 11 inch in
circumference. The weight is about two ounces to
the yard ; while it will bear the breakage strain of
one ton. The cost is estimated at £5O per mile,
without the extra plaited cord. Another specimen
had three wires, insulated as usual, and measures 21
inches in circumference ; this weighs four ounces to
the yard, and has a breakage strain of 11 ton. The
cost of this is estimated at £6O per mile. In fine,
the cord can be made to any thickness required.
The great advantage of this cable appears to con-
sist of its lightness, and its amazing strength, so
that there will be very little strain upon it when
paid out ; while metallic cables are aways liable to
a great strain on being laid, and do not sink so
gently' and gradually to the bed of the ocean as those
made of flax or hemp tightly twisted into thread.