The Sun.
London, England, 1865-06-19 00:00:00

The Atlantic Telegraph.
At length all the preparations connected with the
final departure of this great telegraphic expedition
are completed. On Wednesday the Amethyst left
the telegraph works with the last length of 245
miles of cable on board, and on Saturday the opera-
tion of coiling this in was begun. This work will
probably last till the 22d instant, when the Great
Eastern will have in her as nearly as possible 7,000
tons of cable, or, including the iron tanks which
contain it and the water in which it is sunk, about
9,000 tons in all. In addition to this she has al-
ready 7,000 tons of coal on board, and 1,500 tons
more still to take in. This additional weight, how-
ever, will not be added till she leaves the Medway,
which she will do on the morning of the 24th, for
the Nore, when the rest of the coals and special
stores will be put aboard, and these will bring her
mean draught down to 32ift. Her total weight, in-
cluing engines, will then be rather over 21,000 tons,
a stupendous mass for any ship to carry, but well
within the capacity of the Great Eastern, of which
the measurement tonnage is 24,000. Her way out
from the Nore will be by Bullocks Channel, which
the Admiralty are having carefully buoyed to avoid
all risk in these rather shallow waters. Before the fol-
lowing spring tides set in, about the 6th or 7th of
July, the Great Eastern will start for Valentia. There
she is expected to arrive about the 9th or 10th, and
there she will be met by the two ships of war ap-
pointed to convoy her—the Terrible and the Sphinx.
Both these vessels are being fitted with the best ap-
paratus for deep sea soundings; with buoys and means
for buoying the end of the cable, if ever it should
become necessary; and with Bollen's night light
naval signals, with which the Great Eastern is like-
wise to be supplied. To avoid all chance of accident,
the big ship will not approach the Irish coast nearer
than 20 or 25 miles, and her stay off Valentia will
be limited to the time occupied in making a splice
with the massive shore end, which for a length of 25
miles from the coast will be laid previous to her ar-
rival. This monstrous shore end, which is the
heaviest and strongest piece of cable ever made,
will be despatched in a few days, and be laid from
the head of a sheltered inlet near Cahirciveen out to
the distance we have stated, where the end will
be buoyed and watched by the ships of war till
the Great Eastern herself comes up. Some idea
of the strength and solidity of this great end may
be guessed by the fact that its weight per mile is
very little short of half the weight of an ordinary
railway metal. For the shore end at Newfoundland
only three miles are required, and this short length
will be sent in the Great Eastern. When once the
splice is made from the great cable ship to the English
shore end—an operation which will consume about
five hours--the work of laying the cable will instantly
commence. By this time every mile of the cable in
the three tanks will have been joined up, and at a
stated hour, morning and evening, a series of signals
will be sent through the cable to the land at Valen-
tia, and thence to London, giving the latitude and
longitude of the great ship, the state of the weather,
and the number of miles paid out. The cable will
he first taken out from the forward tank, next from
that amidships, and lastly from that astern ; and if
all goes well the vessels should arrive with nearly 500
miles of cable in her still unused, an excess which
is most wisely allow 3d in case of accident. We may
add that since the paying-out apparatus has been
in work its action has been faultless. Messrs. Can-
ning, Clifford, and Temple have absolute charge of
all the details connected with the submergence. Mr.
De Sauty is in charge of the electrical condition of
the cable for the makers, Mr. Varley goes to repre-
sent the Atlantic Company, and Professor Thompson
as scientific adviser and referee. These gentlemen,
however, are only the chiefs of the various large
departmental staffs which will be on board.
With regard to the process of laying, it is hoped
the Great Eastern may be kept throughout the
whole voyage at a uniform speed of six knots
per hour, faster than which it would not be safe, as
a rule, to run out the cable. At less speed than this,
however, the big ship would fail of steerage way,
and with a beam wini would certainly go to lee-
ward without some counteracting influence. This
influence will be afforded, if necessary, by the pad-
dle-engines, which are to be disconnected, and the
efforts of one wheel at either side would be quite
sufficient to over-balance the effects of anything
but a very violent, storm. The latter risk is
now literally all that has to be feared. Everything
else which human foresight can suggest, either in
cable or ships, everything which long experience or
scientific progress can devise, has been provided,
and the success or failure of this vast expedition is
now only a question of weather. On this only
doubtful point, therefore, it is gratifying to know
that Captain Anderson is sanguine of all doing well.
In his experience of many years and hundreds of
voyages backwards and forwards in command of
the Cunard liners over this very track of the Atlan-
tic, he states that in the early part of July it never
blows long or strong, and that during that time he
had never even heard of any bad weather which
could for a moment affect a vessel like the Great
Eastern. If these anticipations should prove cor-
rect—and there are none better capable of forming
them than Captain Anderson—and if all goes well,
both as to course and rate of steaming, telegraphic
communication with the United States may be looked
for at the latest about the 20th or 21st of next
month. Yet, in the estimate of events, it must not
be forgotton that, in the last memorable expedition
in the Agamemnon, midsummer was fixed on as the
time when a storm in the Atlantic was almost im-
possible, and the records of the Meteorogical De-
partments both here and in America certainly justi-
fied such an expectation, as they showed that for 50
years no storm had taken place at that time. Yet
it was precisely on the 21st of June that the hurri-
cane with which the Agamemnon and Niagara had
been battling for some days was at its height, and
those on board the ill-towed Agamemnon, at least,
knew not from hour to hour which was to be their
last. Most earnestly is it to be wished that on this
great occasion the calculation of averages, if not
more just, may prove at least more fortunate. As
far as regards the cable itself there is absolutely
nothing to be desired.
The Malta and Alexandria wire was an enormous
improvement on that by means of which it was
hoped to connect England with the United States.
That laid along the Persian Gulf is again a great
improvement on the Malta and Alexandria ; while
this which is to cross the Atlantic is a still more
marked improvement on them all. So exquisitely
delicate are the tests that a minute flaw even in one
of the four coatings of gutta-percha has been de-
tected, its place defined almost to a yard or so, and
the length in which it occurred at once cut out. It
is a singular but significant fact that almost all the
accidents and stoppages which have occurred to sub-
marine cables have arisen from those which have
been laid in shallow water. A deep-sea line once
well laid seldom or never gives future trouble, ex-
cept, of course, in those few rare cases where the
line has to be taken over ocean depths known to be
liable to volcanic disturbances. Thus the deep-sea
portions of the Malta and Alexandria line from
Malta to Tripoli have, it is stated, never given an
hour's uneasiness, while the shallow sections from
Bangazi, &c., to Alexandria are constantly getting
out of repair. As a sec-off to this, however, it is
only fair to say that shallow cables may be repaired
with as much facility as they seem to break down ;
while, on the other hand, the first fault of a deep-
sea line is, as a rule, its last.

At the bottom of the Atlantic it is needless to
say that no volcanic disturbances are apprehended.
Along the route on which the cable is to be laid the
depths vary from 1,500 to about 2,500 fathoms. The
dangerous part of this course has hitherto been sup-
posed to be the sudden dip or bank which occurs
about 100 miles off the west coast of Ireland, and
where the water was supposed to deepen in the course
of a few miles from about 300 fathoms to nearly
2,000. Such a rapid descent has naturally been re-
garded with alarm by telegraphic engineers, and
this alarm has led to a most careful sounding sur-
vey of the whole of the supposed bank by Captain
Dayman, acting under the instructions of the Ad-
miralty. The result of this shows that the sup-
posed precipitous bank, or submarine cliff, is a gra-
dual slope of nearly 60 miles. Over this long slope
the difference between its greatestheight andgreatest
depth is only 8,760 ft., so that the average incline is,