Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1868-11-03
The New Atlantic Gable.

From the London Timos, october l5.l
The manufacture of the new Atlantic
telegraph, which is to be submerged be-
| tween Brest and a suitable terminus on
the shores of the State of New York, is
progressing satisfactorily. The new
cable is almost identical in construction
| with those which were completed in 1866,
the only difference being that the diam
\ eter OF the conducting copper core is
slightly greater, and the outside wires
are of homogeneous Bessemer steel, gal
vanized, having breaking strain OF about
1000 pounds, while the wires outside the
existing Atlantic lines have breaking
strain of only 800 pounds. The new
cable will be laid in two lengths-one
from Brest to St. Pierre, in deep sea, of
1926 miles, not including slack, and the
other from ST. Pierre to the terminus, of
1922 miles in length, not including slack.
The latter section will be similar to the
Persian Gulf cable, as it will have to be
laid in comparatively shallow water, and
its exterior wires will be protected with
Bright and Clark's patent silicious COM
pound, which consists principally OF
powdered flint and pitch. The construc-
ton of the shore ends will be similar to
that of the existing Atlantic lines, and
will gradually become thinner until they
assume the deep-sea dimensions. During
the summer her Msjesty's ship Gannet
took soundings along the proposed route,
and from the results OF the operations 1t
is understood that the bottom OF the
ocean is nearly the same in character as
the bed in which the existing cables are
laid, and of about the same depth.
Very little but mud and ooze
we're found along the route. In
order to avoid the dangers of injury
from rocks and icebergs, the new line
will be laid to the south of the present
cables, below the southern edge of the
| Great Bank, so that it may be laid in
deep water. Sir James Anderson, who
will command the Great Eastern during
| the expedition organized for the sub
mergence of the line, has made the fol-
| lowing observations regarding the New
! foundland Banks: "By keeping in the
| five hundred fathom line upon the Milne
| Bank, and around the southern edge OF
| the Grand Bank, there is no possibility
| of ice or any other agency that can be
suggested injuring the cable. The north
ern edge of the Grand Bank was avoided
because it is uncertain at what depth the
icebergs ground. They are said, upon
good authority, to ground at times in
| ninety fathoms. 1t is not certain at
what depth the vessels employed in the
seal trade may sometimes choose to drop
an anchor for the purpose Of keeping In
the track of ice foes. These dangers are
avoided by the track chosen for the pro
posed cables, and / am justified by my
own experience in saying that the track
from the southern edge Of the Grand
Bank to ST. Pierre, aud thence to the
place of landing in America, is entirely
free from any danger from ice, and does
not cross any anchorage resorted to by
the feet OF fishing vessels" The break
ing strain Of the new steel cable will be
seven and half tons, and the strain re-
I ouired for submersion need not be more
| than fourteen cwt. Even if il at any
tine be necessary to haul up any portion
of IL already laid, the strain need not ex-
coed a ton and q half in the deepest wa
ter. The weight Of copper forming the
conductor Of The existing Atlantic cables
Is three hundred pounds PEI knot; in the
new cable Il will be about four hundred
pounds. The Great Eastern has arrived
at Shearness, whence she will proceed
with the cable probably in the end OF
next June. After leaving the Midway
she will 90 10 Brest TO finish coaliug, and
will thence start on the telegraphic expe-
dition.