The Sun.
London, England, 1858-05-31 00:00:00

EVENING, MAY Si,

THE ATLANTIC T.

;LEGRAPE EXPEDI-

TIOX.

PLYMOUTH, MAY 2S.

All the preparations for the trial trip which is to pre-
cede by a few days the actual attempt to submerge this
' cable are being rapidly completed here, and most proba-
bly ere these details are laid I efore the public the wbcle
squadron will have started for their preliminary cruise
in deep water. It was originally intended and expected
that the vessels would leave the Sound on Thursday
morning last, but one cause or another has occurred to
frustrate this arrangement, and it is not now expected
that the squadron will be clear off until to-morrow (Sa-
turday) evening. The Agamemnon, Captain Preedy,
and the Niagara, Captain Hudson, are lying within a
few yards of each other in Hamoeze, and the Gorgon,
Commander Dayman, and the Valorous, Captain Ald-
ham, which have been appointed by the Admiralty to
accompany and assist the expedition, are also anchored
near at hand. The first two named are, of course, the
vessels—the one on board which the coil is stowed, and
from which, in a few more days, it will either be laid or
lost, as Providence may decide. Both are now nearly
ready for the vo, age, and in both the peaceful nature of
the expedition seems, judging from appearances, to sit
with the most remarkably i I grace. Their heretofore
spotless decks are all hegrimed with tar and grease, and
lumber up the pieces where a short time ago it was
almost a breach of the articles of war to leave an un-
tidy-looking rope's end or drop a spot of dirt. Even
the hallowed precincts of the quarter decks themselves
are become as places of no account, mere platforms for
the erection of sheaved wheels to guide the tarry eke
into its ocean bed. Nor are the changes which have
taken place in the internal arrangemer is of each ship of
less importance. Wardiceims and guaroorne are almo t
words of no meanirg ; cahins are transferred and tran •
formed, one ordinary room being knocked into a dozen
for the accommodation af the officers, and a dozen rooms
knocked into one for the accommodation of the cable.
The latter trifle seems to occupy both ships in every
part—on the spar deck or on the keel, in cabins and
almost in berths its monstrous tarry folds are always
present, lying, coil above coil, for hundreds and hundreds
of miles, till the eye is pained and the head made giddy
in vain attempts to follow its endless circles. As may
readily be imagined, with at least 2,500 tons dead weight
on board each vessel, both the Agamemnon and Niagara
astonishingly deep. The lower deck ports of the former
are very near the water, and they are all being fastened
and caulked before starting. But in spite of this the
ka nemnon carries her share infinitely better than her
long black•looking rival of the United Sates, which is
immersed very deeply indeed by her load. The Agamem-
non now only draws 26 feet, or actually one foot lees
than her draught at starting last year; but even at this
depth she bears herself well, and looks a noble ship, and
one that should be seaworthy in any weather. The
Niagara, however, draws no less than 27 feet 2 inches
aft, and this great draught effects a marvellous and most
unpleasant change in her appearance, since it leaves her
spar deck scarcely 8 feet above the water's edge. in
fact, the main deck is actually below the water's level,
and if her 1 ifty bulwarks, some nine or ten feet higb,
were taken away, she would appear to be almost the
very last vessel in the wcrld in wh:ch it was desirable to
venture across the great Atlantic. So much has been
said about this Niagara, and such exaggerated rumours
have been afleat respecting her general capacity as a war
steamer, that many of our readers way be surprised to
learn that as a war steamer she is almost a total
failure. There have been bad bargains out
f our own dockyards, Heaven knows, but
they have never yet gone so far as to produce a wall-
sided frigate of almost double the tonnage of a line-of-
battle ship, yet only capable of carrying 12 guns on her
spar deck, and none at all on the lower. Any other
screw vessel of the same size as the Niagara should be
well fitted for carrying at least 100 cf the heavies.,
ordnance used in warfare. Her share of the cable is
admirably well distributed throughout her entire length,
and thu-a of course, any chance of undue strain in a
heavy sea is in a great measure obviated. Still, strange
to say, though time() on board assert that she is a munch
stronger vessel than the Agamemnon, her decks appear
to have given down under the pressure of the enorm us
coils to a much greater extent than is perceptible on
board the latter. On that ship the great bulk of her
share of the wire is stowed, as before, in her capacious
hold. Last year it wit, all coiled in one immense circular
mart., nearly 100 feet deep in circumference. By this
arrar gerneut, however, the pressure of some 1,300 tons
upon such a small surface was found to be greater than
the ship would bear with safety, and it also conduced
to her rolling to an extent that Has dangerous to the
process of submerging. To avoid this, therefore, the
hold has been enlarged, and the coil is now laid in a
mass, about 60 feet long by some 45 feet wide and 20
deep, and every precaution has been taken to prevent its
fouling or cemtng up in "kinks" while paying out. In
addition to this coil there is yet to be one on the orlop
deck of 95 miles, and there is one near the forecastle of
230, and a small one of 20 miles for the experimental
cruise. In both vessels the paying-out machines are
fixed on the starboard side, well astern, and the machines
for reeling in the coil in case of aria, accident oceurring
or "kink" pa-sing overboard are on the port side. Both
these machines have been ac iveiy at work since Wednes-
day, and the regularity and ease of their motion has
bees all that could be desired. Whatever accident may
mar the expedition this time will certainly not be due to
these portions of the submerging apparatus. The
mechanism of this machinery, which was devised by
Messrs. Penn, Field, Lloyd, and Everett, and the manner
in which it is fitted with Appold's break, has already
been so fully explained in our columns that it is needless
to describe it further. Tne experimental cruise to te-t
its character and capabilities is almost of a purely formal
character, and undertaken more fur the sake of showing
that no possible precaution towards success has been
neglected, rather than in the belief that any improve-
ment can be suggested is the working of the machinery
ewpkyed.

The programme of the intended proceedings of the
exp.tdition mAy be very briefly told. According to pre-
srmt arrangements the vessels leave the Sound to-morrow
evening, and set with all speed into deep water. Directly
they are out of "soundings" (meaning in about 2,000
fathoms) a piece of waste cable will be passed from he
Agamemnon to the Niagara, and a splice made. Only
this experiment can teach practically the best method
of effecting the important junction when in the middle
of the Atlantic. The cable will then be sunk from both
vessels, and, after a variety of experiments have been
macl,-., as to its strength, by means of running out, &1.,
the " reeling in'' machines will be set to work to at-
tempt to coil it up again. This latter portion of the tack.
though not altogether impossible, is so full of difficulty.
that but little hopes are entertained of recovering the
piece with which the experim'nts are made, and which,
to the length of some 30 r4O miles, will, there is
little doubt, remain as a permanent ornament to the
bottom of the Atlantic. Toe loss of the piece, however,
is of no consequence, ,ince, apart from the practical
value of the results it will furnish, it can have no other
use. It is a portion of the coil lost in the attempt of
last year, and which was so injured in Wallin', up from
1,000 fathoms as to become, electrically speaking, of no
further value'.

This txperimental trip (which is likely to last about
six days) fiaished, the vessels return at once to this
pert, and when the ships fill up with cal and water
the Agamemnon will receive her last coil of 95 miles
(making up the total quantity on board of both,
exclusive of the shore ends, to 2,96 G), and, the filial
preparations being completed, the squadron will sail
for the great undertaking about the sth of Jtne. Our
readers are of course aware that the cable will be sub-
merged by bosh ships from the centre of the Atlantic,
instead of commencing from the Irish coast as was the
Case last year. There are welt strong reasons in favour
of the present plan, which is the to igival one, and which
though abandoned for a time, was warmly advocated
last year, by Mr. Bright, the engineer of the company.
The chief advantage, of course, ie, that by laying from
the centre by both ships the whole operation can be
finished in half the time, and therefore at ball the risk
ftorn bad weather which it would otherwise incur. Tae
plan, however, is not without serious risks of its own,
but the manner iu which these are to he net has not as
yet been finally decided upon. The Niagara will be
given an advantage over the Agamemnon of some GO or
101) rni'es ; that is, the junction of the wires will n. t be
made exactly midway between Valentia and Newfound-
land, but at the distance we have mentioned nearer to
the American shore. No attempt will be made to effect
the splice until the weather is fair and the barometer
tising, Once, however, that the centre piece is resting
on the bottom, both vessels part and make all safe speed
to their respective shores. The rate at which the cable
will be lowered out will not be allowed much to exceed
five knots per hour. During the whole process, of
course, signals to ascertain the perfect continuity of the
coil will be passed from ship to ship, and a'l questions
and answers regarding the rate of speed and state of
weather with which each vessel meets kept regularly re-
corded. As regards the chances of bad weather, the
moat careful and elaborate investigations have been
made on this subject by Lieutenant Maury, of the
United States' navy, and therefore, as far as linroan
foresight and science can go, the risks have been at least
foreseen, and these fore partly guarded against. Ac-
cording to this officer and to the statistical tables
of the Washiugton Observatory, where the whole
subjsct of the frequency of gales, fogs, ice, arid
lightning in each month for the whole North
and South Atlantic has been compiled from up-
wards of 260,000 days of observation., it seems
that in the months of January and February that
part of the Atlantic that lies between England and
the United States is the stormiest known sea in the
world, and that along the telegraphic route there always
occur at least five, and perhaps 10 gales of wind during
the January of every year. In the summer season the
part of the Atlantic to be traversed by the paying-out
steamer going west is almost entirely exempt from gales.
Os the contrary, along the eastern (European) half of
the route there occur annually en the average at least
two or three gales in the months of June or July. There
is, however, scarcely any chance of gales in the month
of August, except in approaching the Irish coast, when
the chances of encountering one are about as 3 to 30.
On the other hand, the steamer going west with the
cable, though much less likely to encounter a gale, has
to contene with almost as great dangers from fogs and
ice. For ice, it appears from the logbooks for souse 830
summer voyages between Valentia and Newfoundland,
that 1 in 10 report meeting it June, 1 in 24 in July, and
lin33 in Ati,4ust. Thus, according to the relative fre•
quency of gales and fogs along the whole route in the
month of June, it seems that the English vessel risks
encountering five gales and no less than 22 fog banks,
for June is the foggiest month in the year in the North
Atlantic. The American ship has the chance of meeting
two gales, but no fewer than 37 fog banks, as well as the
chances of ice, which is always met with in her route,
but much less frequently on the English side of the
ocean. Calculating these dangers, therefore, by the