Daily Nashville patriot. [volume] (Nashville, Tenn.) 1857-1858, 1857-09-10
From the National InteIligencer.


We have already alluded to the fact that the con-
tingent occurrence of the particular accident which
proved fatal to the recent experiment in laying the
Telegraphic Cable had been previously indicated
in an able scientific paper by Lieut.. J. NJ. BROOKE
of the Navy, and which appeared in this journal
early in the month of May last. We to-day have
the pleasure of presenting TO readers from the
same intelligent source the following instructive
observations bearing upon this topic, as well as
others connected with the practical execution of the
great work, of whose eventual accomplishment it
is gratifying to observe that Lieut. BROOKE does
not despair though his scientific knowledge ena-
bles him to foresee even greater difficulties and
more varied casualties than appear TO have been
spprehended by those who first embarked in the
enterprise:
WAsHINGToN, September 3, 1857.
To the Editors Of the National LuteIiigencer:
The late unfortunate result of the attempt to lay
the telegraph cable has given rise serious doubts
as to the eventual accomplishment of the project
The papers of the day TEEN with fanciful supposi-
tons as to the causes of the mishap. 1t may be
shown, however, that neither mysterious nor in
surmountabe obstacles are opposed to a successful
result; for in every particular, the circumstances
attending the operation-the movement Of the ca
bic, the temporary interruption of the passage of
the electric fluid, and the parting of the cable, In
certain contingency-were clearly indicated sew
eral months ago. In the essay, "0cean Telegraph"
published in the IntelgeDcer and from which
quotations bearing on the management of the cable
have been recently made, the tendency Of the cable
to sink in the direction of its inclination point
ed out, and in this back-set" is found satisfactory
explanation of the remarkable under-currents that,
refusing to touch the deep-sea sounding lines laid
in wait to seize and bear away the cable on which
hung the hopes of nations The principle which
enables US to beat TO windDard, by inclination of
surfaces, consequent decomposition and re-compo
sition of forces applies well to the descending
cable as to the sail-boat, which leafs into the eye
of the wind"
We may reasonably anticipate waste if a cable
be permitted TO descend at an inclination OF per-
hsps thirty degrees from the withdrawing the
swiftest line of descent-approximating the cy-
clodal curve. And the secret OF the apparently
anomalous interruption of continuity lies in the
following paragraphs of the essay:
'Itremains to be seen, in practice. whether these
various materials have been most advantageously
combined.
suppose that the copper and iron wires were
straight and parallel; in that case, since the rea-
tive ductlity OF these metals s about four to Ve
In favor of the copper, the iron wires would practi-
caly bear the strain, relieving the copper; and
this, without regard TO change of form in the core
of gutta percha. But in the cable now in process
of manufacture the outer wires make two whole
turns to the feet. 1t becomes, then, a serious
question, whether by strain, the pressure of five
six thousand pounds to the square inch, the
will be mpressed or altered in form. The water
penetrating between the iron wire will surround
each part of the cable, and on them, individually,
exert its powers of compression. If the gutta-per-
cha yields, the iron wires will become loose-will
extend-and the strain will come on the straight
copper, dTdloing IL; and, although it may yield
twenty per cent. of its length without breaking,
any such process involves risk
"The character of the curve assumed by the ca
Bile on its way to the bottom will depend upon the
velocity of its descent and the speed of the ship.
"If the cable, when extended horizontally upon
the water sinks faster than the ship runs the
Vexty Of it's curve will be towards the bottom; the
upper portion, nearly vertical will descend more
directly, and therefore more rapidly, towards the
bottom; the lower portion will consequently be de-
posted az t0aVes upon the bottom"
The conducting wires broke; the gutta percha,
stretching with the outer wires drew the broken
ends apart, and continuity then interrupted.
But when that portion of the cable approached the
bottom it became slack. "Ihe cable SOiLL be depo =
Sted an WaUes upon the bottom" Then the gllttG-
percha relieved of the strain, by virtue of its elias
ITCHY contracting, drew the broken, separated ends
of the conducting wires together, and continuity
is striking proof of the fact that the conducting
wires were broken, while the gaata-percaa remain
ed unframed. Had it not been re-estabshed the
interruption would have been generally attributed
to abrasion OF the gutta percha, aud the error Of
construction you'd haze remained ttneEDOSed.
In view OF these facts, fulfilling as they do, even
in detail predictions made months ago, forming
part of an essay which, upon equally good grounds,
predicts the eventual accomplishment of the enter
prise, we may feel assured that day not far
distant we shall have a living ocean telegraph.
j. NJ. BROOKE, 1t. U. S. Navy.