The Express.
London, England, 1857-07-16 00:00:00

THE ATLANTIC TELEGRAPH.

We understand that the soundings obtained by her
Majesty's steamer Cyclops, which has been engaged in
checking for the Atlantic Telegraph Company the Bounding,
taken by the United States steamier Arctic, are very satis-
factory, bottom having been found all the way across the
Atlantic, and for the greater part of the distance composed of
gun sand and small shells near this coast email pebbles
were found mixed with the sand. The greatest depth
sounded was about 21 miles. Captain Daymen has some inten-
tion of looking into Trinity Say, but wu undero and ho is
expected in Queenstown by a certain date, and is fearful of
losing too much time by making the trip thither.

In the Express of the 7th instant, we gave an
account of the manufacture and the shippieg on board the
Agamemnon at Greenwich, of a portion of the submarine
etwhich is to unite this country with America in tele-
graphic communication. The other half of the cable, 1,2.50
miles in length, which Means. Newel and Co. contracted to
supply, has already been completed, and is in coarse of
delivery on board the Nugent, at Birkenhead. The Niagara
is a screw steamer of 5,200 tons, pierced for twelve 11-mch
gene, belonging to the United States navy, and is under the
command of Captain Hudson, an officer of considerable ex-
perience, basing been attached to the service an far back as
1812, and having taken part in the Pacific Exploring Expe-
dition. The Niagara is 345 feet in length, by 56 feet
with engines of 1,000 horse power, ands the largest by=
afloat in the world. tier Acres. is a Grifeth's propeller.
flha is sthelseed in the Meracy, to take on board
the ebb. snit breath having prevented her from
baigVsledbar Illebunined. The inner gates of the dock at
Iffirkeelesed would Ism been quite large enough ; but, un-
istunately, the outer gates, which are 20 feet less than the
Inner, are only 50 feet wide. The Niagara hes now bees re-
ceiving the cable for upwards of a fortnight, and it is being
celled on board at the rate of sixty miles per day. Up to
Tuesday evening about 800 mile. Dad been ahipped, so that
the whole of it will have been stowed on board in the coarse
of a few days front the present date. In order to make rem
In, the immense coils in which the cable is deposited in the
vessel, the forehold of the Niagara hes been cleared of the
chain lockers, coal bunkers, and tanks, and fitted with • level
floor over the kelson, the beans having each been trussed
with double stays, to compentste fur the removal of
Ile stanchions. Part of the cable is also being
stowed in • space which has been cleared out on
the main deck, abaft the engine-room, by displacing
some of the officers' berths and enctoaching on the ward-
room. Three smaller revels, of 500 tons each, the Wallace,
the Ellen, and the Perthshire, convey the culla from the
works of Messrs. Newell and Cu., at Birkenhead, to the
frigate in the Sloyne, and two of these craft went lying along-
side the Niagara, one on either side, on Tuesday, and seen
at a little distance, from the river, served to bring out the
Teatime of her dimensions moat completely. The cable, of
the manufacture of which a very minute description was
given in the article above referred to. has • thick coating of
pitch and tar upon it, and the docks on which the cable
rests, have been covered with sheet lead to prevent the tar,
which accumulates at the bottom of the roil, from soaking
through and saturating the timbers. The weight of the
portion on board the Niagara will be about 1,200 tons.
The process, of coiling is one which seems to
pose= great interest in the neighbourhood, and steamers
from Liverpool are constantly conveying visitors to the
Niagara, whom Captain Hudson courteously allows to ta-
mped the work. Among the vnitors on Tuesday were Ste
William Cubitt, and Mr. Wm. Fairbairn, of Manchester.
The coiling on board in under the superintendence of Mr.
Wondhome, C.E., who took part in laying down the Varna
and Hilaire& telegraph, and this gentleman will accompany
Mr. C. Bright (who is the engineertin-chief to the company,
and was one of the original projectors of the submarine line
IC7o6llthe Atlentir) in the Niagara. to assist in laying down
the half of the cable stretching from the middle of the
Atlantic to the American shore. Three two gentlemen will
have to take alternate watch in the Niagara of the paying
out of the cable during the progress of the work ; and Mr.
Canning, who laid the line lICTOeB the Gulf of the St. Law-
rence, last year, with Mr. Webb, who has been engaged for
some years in laying down and raising the cables between
Orfordnees and the Hague, will take the some charge on
board the Agamemnon. The machinery for paying out the
cable has been made with greet prompt tulle, by Mesas. C.
De Bergue and Co., of Manchester. The operations at
Greenwich, at we have before stated in the Express,
have been assisted by two of the ablest electricians of the.
day, Dr. Whitehouse and Professor Morse.
The two vessele, the Agamemnon and the Niagara, rail
about the 26th inst., and are to le joined by her tlejesty's
frigate Leopard and the United States frigate Susquehanna.
Thee, are paddle-wheel atenntera of considerable power, and
are intended to pilot and mare the ether vesele when neces-
sary. The four meaniers are to rendezvous in Cork harbour,
and will probably rail together f thence about the let
August. Their first destination will be let. 52 deg. 4 min. N.,
and long. 32 deg. 32 Mill., or the central point of the are of
the great circle between Valenti& Harbour end Trinity
Bay. Having welted here for favourable weather, aboula
the &meets not be peopitious to the design on their arrival,
• " silica" will be effected between the half of the tele-
graphic cable on board the Agamemnon and the half on
thud the Niagara, and they will part company--the Niagara
and Suaquehanna sailing weatwsrd, for frinity Bay, New-
foundland, distant 900 to 1,000 milts ; and the Agamemnon
and Leopard returnine eastward, paying out their portion of
the cable until they make Valentie Harbour, on the coast of
Ireland. The arc of the circle thee indicated is 1,834 miles
in length, so that could each vccoel steer an exact course to
it. destination, not subject to the errors of the magnetic
needle or the disturbing influence of oceanic currents, each
would have to pay out 917 miles of cable, but
as that is impoeeible, each vessel has been sup-
plied with • surplus length of about 300 mites,
to meet all emergencies. Supposing that each vend'
should be able to pay out the cable at the rate of about
five knots per hour, or 120 per day, it will thus be seen that
the operation of dropping the great international link be-
tween this country and the United States will have been
completed in eight Jaye from the time the "splice" is
effected in mid-ocean and the vowels part company.
The outer coating of the greater part of the elide contests
of • mil of 18 strands of seven•thre td iron wire, as a protec-
tion to the gutta perch& cla, containing the telegraphic
wine, from friction or other injury until it has been
safely deposited on the bed of the deep Atlantic. But
those portions of the cable which will have to be joined when
the vessels part company may possibly be subjected to an
extra strain as the firm unbroken link of it wink., between the
sterns of the two vessels to find its ultimate resting place,
and to meet this potable contingency ten mike length of
this central portion of the cattle has been protected with •
sheath of 18 steel, instead of iron, wires, and is suppneed to
be capable of eustaising a strain of 12 tons. The machinery
made by Messrs. Do Bergen and Co. include, paying-out
sheaves or drums of five feet in diameter, having grooves
corresponding to the thickness of the cable, with
a friction drum attached to them revolving three
times as felt se they do, and with brenkage
power to check or retard the motion of the sheaves at
pleasure. From the hold of each ship the cable, pawing
over four of these sheaves to • few feet above the poop deck,
will be dropped into the sea over a fifth eheave, placed above
the stern. The exact amount of strain will be constantly in-
dicated by an instrument for the purpose under the eye of
the brakeman. At the aides of the vowel will Meng down
into the water new electrical logs, principally due to the in-
genuity of Mr. Charles Bright, the Atlantic Company's
chief engineer. These immersed loge have vanes and
wheels revolving at a rate proportioned to the pottage
of the ship through the water, and making an electric
circuit which is broken at each revolution. An electric wire,
from the lug to the deck, records there every revolution of
the log, and consequently the exact speed of the ship. It
tenet not be supased when the ships part company that com-
munication will hist between thole on board the eased..
The electricians hare hold of either extremity of the culla of
the cable, and will interchange eignals constantly, so that
each yeast will be mutter of the other', fate, and of every
incident that may help or retard the propene of eubmersion,
unless some unfortunate emergency should ramp the link.
When the termed. of the chips here suck beneath the
horizon, and they are lost to view by the look-out •men, the
inter-oceanic current of electricity will give instant record
of all that theme until the lengthening line of cable
hoe been spun out from shore to shore. A bell on board
each vessel will sound every second as each portion of the
cable is payed out, and its silence will probably be the
first indication of any ruiehap arieing frosn friction or over-
tension of the cable, and the verde will have apparatus on
board, so that in any such emergencies they can be backed,
the cable recoiled until the faulty place is found, when a
piece will be cut out and the perfect portions reunited with as
little delay as peeible. In case of a storm, apparatus has
been provided to allow for any extraordinary strain that may
occur, and, if necessary, for cutting the collo without let-
ting the outer end of it clip to the bottom of the meth,
whence it might neverbe recovered. In such en emergency
there are large reels of auxiliary cable of great strength,
which could be attached to the end ; and these auxiliary
cables can be suspended from Inge tloatethaped buoys on the
martens of the water, capable of resisting a very considerable
'nein till all danger he. passed.
The month of August has been chosen for the submersion
of the cable as likely to afford the beet conditions for the en-
terprise in regard to weather. The three great obstacles
most tope feared in such awork were fogs, floating kw, end
storms. There. the greatest freedom from fogs in winter,
from storms in June, and from lee in August, and upon
consulting Limit. Maury, from the 20th of July to the 12th
of August has been fixed upon an the most favourable period
for the undertaking. It may therefore be confidently anti-
cipated that the result of this great enterprise, to which every
one must heartily wish complete success, will be known to
the world by about the 10th of next month, or. possibly at an
earlierdate. The spirit with which Lancaelurc entered into
the project which is being so rapidly put into exeetttion
is
indicated in the fact that 150,0001, of the capital has been
subscribed in that county.