Democrat and sentinel. [volume] (Ebensburg, Pa.) 1853-1866, 1858-10-06
THE CABLE.

The Loudcn Times of the Stb inst IN an
article Or the Atlantic Telegraph. explains
the cause of au interesting fact. - wit that
while it is possible to transmit Q signal from
New foundland to Ireland. it may be. and has
been impossible to return one. The article
is of such importance to proper understand
ing of great scientific problem, that We
transfer it to our columns
'.The bond of electrical union between Ire
land and newfoundland consists Of copper
strand, containing seven twisted wires OF pure
copper Each wire is not much thicker than
thread of sewing silk, and section OF the
rope formed by the twisting of ali 5eren, not
much thicker than the head of an ordinary
sized pin Suck is the thickness of the cleo
trical road to America under the depths OF
the ocean. The gutta perchs coverings OF
this copper rope, as well as Its hempen and
iron wire shea,bings, are only for the insuia-
tion and support Of the precious core.
OF all the marvels of modern electricity,
perhaps the most astounding is this that ell
ther water or earth will serve as return
wire for the telegraph. When the electric
telegraph was first introduced, it was suppo-
sed to be necessary to lay down, or erect, two
insulated wires between the stations from and
20 which signals were to be received aud de-
spatched. Sup9osing, for instance. we wish
ed to communicate between London AID Ed
inburg the electrical current could only be
sent from London to EliDburg, 50 as to re-
cord itself, upon the condition that there
should be some means by which it should
travel back again to the place from whence
it came.
! The electrical current could only be crea-
ted in London and detected at Edinburgh by
/ the existence Of Two electrical rods-oEe TO
/ carry the current and the other to return 1t
so as to esta abish what is called complete
| or closed circuit. This required two wires
| one to carry the message, shock wave, or
! current, from London to Edinburgh, tbs eth
! er to return it. Ii vas soon discovered, frst.
! that wherever there existed an unb. oxen body
| of water, it might be substituted for the re-
| turning wire; and secondly, that the earth
! itself, for all known distances cf electri al
stations, might be similarly used
How it comes that earth or water acts 4
means Of enclosing or completing the electric
currcIt, is not yet we'll understood. 1t is
one Of many marycls cf science, well deter
mined. yet hard to grasp intellectually EI"c-
trical wares or currents, call them what you
will, have been transmitted from Irelaa-d to
Newfoundland, through two thousand miles
of copper ropa Eut thicker than a bodkIni
these currents have found :heir way back
through the earth, under the depths of the
Atlantic ocean, accurately y TO the spot from
wherce they started. How have they found
their way back again? Has the subtle light
ning forced path through the SHORES! mail
euiatical line from the spot where the cope
wire dipped into the earth at Neu:ouu j and
to that where the otAer end Of the l,ue /
buried in ireland? Are we to conceive som,
III a. Q,v IL,
veIlous vibration Of PARTICLES of rnatu'r trans
mittod, by the shortest route. between tn
two earth ends of the cable OF Is it diffuse'
through the surface of the earth for some uu
known distance Gu each side Of TINS uafro'
path? Are we, iustead of these processes, ;
hard TO conceive, 10 suppose tue earth grea
reservoir OF NATURALIZATION tor molecular dis
turbance, ihat ihe PARTICLES OF the vile b.
ing disturbed by electrical Vibrations, tb
! earth At both eu,is Il the wire may ncui.aliZ
these vibrations when both the uIIus Il
+ , contact with II? These are solnr OF the sci
eutific specuiatIous A. 10 the TuitOHdte OF tn
fact that The earth serves as return wire I"
, / any lengths of electrical cable, provided tina
caule b= kept through hout its whole length GU
/ Of electrical communication with the earth.
This scientific aigressiou is necessary It
render conceivable the fact stated by Mr.
Whiteheuse, that the transmission OF signal
from Newfoundland to ireland continued un
Interrupted, while they could not be trans
mtted from ireland TO Newfoundland,
the copper rope had been completely broke
across uud the ends separated from contact
40 signals could have been sent either way
! But if there existed leakage o! clec;ricit
near one of the stations, dimiuu ION
the conductibiIity of the wire, by its attenua
, ton or some other Cause, 81 gnai might
received at tha; statiou, though it could Il,
, be transmitted from.
, The intensity OF a current Of cl cctricity $,
, through any length of electric wire or cab
is diminished TO some ratio, depending up;
the length Of the wire through which it pa
, ses. The current, which may be Ct great il
= tensity as it leaves Newfoundland, becon
much weaker as it reaches Ireland rs
= leaves Newfoundland, it would perhaps pa
alyze you: as it ncaIs Ireland you might tai
+ it with impunity. Now. il there he an il
+, eruption or leakage, not total st"ppag
q | of the electrical current near Ireland, the en-
!, rent sent from newfoundland to ircan
might suffer great diniiuution of lptensi
h lear Its destination, and yet be strong enous
Y to make itself manifest to the recording i
: strument in Ireland. On the other hand. Il
Y current sent from Ireland to Newfoundlau
j. suffering a great loss OF intensity near
starting point, might not, AFTER Its dimiauh
of intensity, be able to record its presence
Newfoundland.