The Sun.
London, England, 1860-04-09 00:00:00

THY„' SUBMARINE TELEG.RAPS TO

GIBRALTAR.

The unfortunate failure of the Atlantic telegraph,
-with its long series of mistakes and miscalculations,
has exercised, and still to a certain extent continues
to exercise, a depressing influence upon all im-

portant schemes for submarine telegraphic commu-
nication. We can scarcely say that confidence in
the working practicability of any Atlantic telegraph
whatever, submerged along the old deep sea route,
has yet been established, while, regarding such a
scheme merely in the light of an investment—a
commercial speculation by -which money is to be
made, we need not remark how,at the present time,
even the best inaugurated enterprise of the kind
would soon have the grief _of seeing its shares at
half discount unless the most rigid and practised
caution was exercised bah in the choice of route
and choice of cable. In the meantime, during the
stagnation that has engulfed all such projected
schemes since the Atlantic cable was designed and
lost, a great reform in the method of constructing
submarine ropes has been going steadily forward.
The old self-destructive principle of ponderous iron
coils for,deep sea wires has been so generally aban-
doned, that a proposition for now reverting to their
use across a sea of any length or depth would not
be entertained for a moment by telegraphic en-
gineers. To be sure this change, which of course
was, and still is, fiercely opposed by some of the wire
ropeipakers, has not baen brought about till the cre-
dulity and patience of shareholders were at an end,
and until the bottom of the Mediterranean, and
other seas, had been fruitlessly adorned with three
orfour of those leviathan coils, enduring monuments
of our commercial enterprise and of our mechani-
cal ignorance also. This journal was neither slow
nor lukewarm from the first in pointing out the
inherent faults of construction which led to this
fearful waste of money, and—still worse—which
gave rise to fears in the public mind that long lines
of submarine telegraphs presented insuper-
able difficulties. Our columns at the same
period also bear testimony in many letters from
electricians and engineers that some who are
now most forward in supporting the principle of
comparatively light cables were then most strenu-
ously opposed to them, and most urgent in denounc-
ing the advocacy of the press in their behalf. Since
that period—only four years ago, though marking
an age in the infant science of telegraphy—opinions
have undergone a most important change, and both
contractors and engineers now lean so strongly to
very light cables that the idea, like all good ideas,
is in danger of being led into extremes, and we may
see as much public money lost in trying to sub-
merge cobwebs as was ever dragged down " fathoms
deep," even by those expensive wire•covered cables,
big enough and:heavy enough to moor an island.
The results of this great alteration in the weight
and strength of cablee are likely soon to be practi-
cally tested on the most extensive scale, by the pro-
portionate success, or non-success, of some cables
which are now being manufactured in England.
One is about the very lightest cable of its kind that
has ever been made at all, always excepting the
guttaperch a-covered copper wirewhichwas stretched
across the Black Sea to Balaclava. The other is to be
a well-proportioned "composite" cable, heavy and
very massive, perhaps far too much so in some
parts ; in others, where it is proposed to be sunk
some three miles down, it is, if not quite a light
rope, still, with regard to lightness, an important
example in the right direction.
The first-mentioned extremely light cable, which
will weigh less than 3ewt. per mile in water, is
about being constructed at the Electric Cable Com-
pany's works, Milwall. The heavier, and we must
say the more expensive proportionedrope, is in pro•
gress of manufacture at Glass and Elliot's for the
English Government, and will, it is hoped, before
neat winter unite this country with Gibraltar.
Those, however, who suppose that the question of
the relative merits of a medium light cable or one
of the lightest possible construction will be entirely
set at rest by the ultimate success or failure of
either of these two kinds of rope will be mistaken,
inasmuch as the contract price allowed i for
the very light cable we have mentioned is
not, we imagine, sufficiently high to insure the pro-
duction of the best article of its kind. On the other
- hand, with the cable to Gibraltar, all questions of
cost have been considered at tshe Treasury as entirely
subordinate to procuring the very best workman-
ship and material—the highest conditions of me-
chanical and electrical excellence which it is possi-
ble to secure by money, toil, or ingenuity. Both
these cables, nevertheless, mark important epochs
in the quick progress of ocean telegraphy, and as
their success—though one is removed from the or-
dinary limits which govern commercial enterprize
—is likely to influence in the most important degree
the construction of all fature cables, we shall take
occasion to give our readers some insight into their
chief peculiarities.: None will require to be told
that for this country it is a matter of the very last
importance that the Government should have the
means of instantaneous communication with Malta
and Gibraltar as they have now with Woolwich or
Portsmouth. In fact, it seems somewhat astonish-
ing that England, which has manufactured thou-
sands of miles of cables for every other empire,
should still be entirely dependent on Continental
overland and submarine lines for a means of com-
munication with the very centres of its European
power. Before next winter therefore we may hope
to see the first steps taken towards putting an,end
to this vary unsatisfactory -state of things, and a
working telegraph laid from England to Gibraltar.
Before next year is out, tl the first line is success-
ful, a similar cable will unite Gibraltar with Malta,
while before the close of 1862 the line from the
latter Wand to Alexandria, and so on, via Suez and
the Red Sea, to India ought to be complete, taking
it • for granted that the Red Sea lino
continues in
good working order.
The.direct route from this country to Gibraltar
would for the most part lie through what
in telegraphic works would be oalled deep
water—the route from Brest to Finisterre,
and so on round the coast of Portugal, at a compara-
tively short distance from land, averaging on the
whole either 1,000 or more than 1,000 fathoms.
But in this cable (as should have been the ease with
every one that has ever been made) the contract
with Glass and Elliot is not only for its manufac-
ture on a certain plan but for submerging it success-
fully. The depth of water in which it will ulti-
mately be laid will, therefore, doubtless rest in a
great measure with the contractors, subject of course
to certain conditions of the government that it shall
be sunk is water deep enough to keep it out of the
reach of any enemy either to raise or to break.
The latter consideration is, of course, one of the
last importance, since only in war time will attempts
be made to injure it, and in war trine, above all
others, its services would be absolutely indis-
pensable to the country. It is in reference to the se-
curity of the rope from injury that some uncer-
tainty, we are sorry to say, still exists, as to the
beet of two places for landing the cable here—Fal-
mouth or the coast of Ireland. In case of the fer-
nier being chosen the route must take from this
country a south-westerly counsel, in order to give a
wide berth to Brest and Cherbourg, where the
ater shallows to 80 or 100 fathoms, and- in which
an enemy's frigate properly provided with grap-
pling irons could either raise or break the wire at
a day's notice.
After passing Brest, howeier, the
rope can always
be kept in deep
500 to 600 fathora. soundings of from
except for about 300 miles
across the centre of the Bay of Biscay to Finisterre,
where the groat depth is nearly 2,700 fathoms,
and where at no,partfnr a length of 270 miles :is
there less than 2,50 D, Fromb between et Finisterre, which
cawn this country
is almost precisely dway
and Gibraltar, the contractors choose their ow
depth, and, we need scarcely add, it is to b hopedn
that the Government will take care that they place
e
their sable where neither friend nor enemy can ever
reach it. The great and almost fatal objection to
this route, of course is, that after leaving Falmouth
- the wire, must remain for a length of nearly 800
miles in a depth *of water nowhere exceeding 200
faikoms, and genera* very considerably less. All
telegraph engineers know that at this distance
from the surface any cable, no matter its thickness,
can be either raised or broken--witnees the recent
fract::.re by an empty Indianian of one of the