The Caledonian. [volume] (St. Johnsbury, Vt.) 1837-1867, 1857-03-28
New Scheme for Trans.A,Ian,ic
Telegraph.
From the Boston Journa

n'S o"h, WHICH he cOntenu5 WILL realize the
great object sought to be accomplished. A.
this IS topic of great public interest at tn.
present time, an explanation of Mr.. Hail.
views and plans, as published in the Scientific
american, will perhaps be acceptable to our
readers.
MIR. Halls reasons for predicting the fail.
ure of the plan now in progress, are, first
That there has never yet (to his knowledge
been transmitted communication throuoh
continuous wire 245O miles in length bu,
even if such an experiment has been success.
fully made on land, it could rot be accom-
plished with submerged wire. A coil of
ever so we'll insulated, if immersed in water
will not effect an elcctro-masnet with the
same power as if tested out of water. The
proximity Of thi, element produces .ensi.
ole effect upon the electric current, and
would, in the length of cable proposed, en-
tirely absorb the subtle fluid, especially all
that could be forced through so small wire
as the one contemplated. But even admit.
ting communication possible, it is known
to electricians that in submerged wires per.
ceptible period of time elapses in the passage
OF the current, and that this period increas.
es with the length of cable, and that it rs.
quires some seconds of time before the wire
is unchanged after each signal. In the length
of the cable proposed, it would require over
six seconds for each signal, making less than
halt newspaper column for twenty four
hours work.
The reason why the signals are 50 much re.
;arded is thus explained -
The reason why electric signals are So
much retarded in wires encased in eutta per.
cha. and laid under water. is owing to lateral
indu1ion. The insulated wire assumes the
character OF vast Leyden jar, the copper
wire representing the inner coating. and the
water outside of the Sutta percha the outer
coating. This literal inIuc,ion of the eIec-
TIC fluid in the cable, not only retards the
current passing through it, but when one
electlc wave Is sent through the wire, ano,h-
or wave or signal cannot be sent until the
reflex. or return wave has escaped; and the
time required for this is twice as long as for
the direct wave"
The second reason assigned for the failure
is the improbablity of securing a perfect in
Sulation with so thin a coating of outta per
cha for so many hundred miles of wire, when
the slightest particle Of damp, even the prick
of pin through its covering, would DESTROY
the whole work. The third and final obiec-
ton IS that it will be almost impossible to
lay so long cord without an accident, from
ships surging. when a slight strain would dam
age the central wire or its covering.
The plan which Mr.. Hall submits for pub.
lie approval, as the only practicable scheme,
is one in which the leading feature is to
shorten the telegraphic circuit, by construct
ing floating telegraph stations, to be perma.
nently anchored at suitable distances apart.
directly in the line of vessels running be-
tween New York and Liverpool. These
stations would be constructed in a peculiar
and Substantial manner, with but single sto-
ry above the water and to be secured to the
bottom of the ocean by wire cables, ra,liat-
ing in every direction, and secured by heavy
anchors. lie says
"a floating station of this kind every five
hundred miles. with suitable force and ma
terial, would make the electric circuits 80
short as to render them perfectly reliable,
besides answerin. purposes of infinite i'm
portance to the shipping interests of the two
great countries they connect. When located
they would have their fixed places on ocean
charts, and should any accident befall a shin
in mid ocean, it would, of course, make for
the nearest station. when aid could instantly
be te!egraphed and sent from the nearest port
Besides answering the proposes of light -hou-
SEES and ocean marks Of the commerce of the
world, they could report the progress of ves-
sells plying between the two ports, to the
great interest and satisfaction of friends,
whereas now. the fate of thousands of lives
and millions of property is hid in weeks and
months of anxiou. suspense"
Mr. Hall purposes that each cable should
contain at least four separate conducting
wires not only to provide against the chanc
of single wire becoming damaged, but to
allow a number Of operators to transmit
messages at the same time, as the amount of
business will no doubt require it. The ca.
bIe will be suspended at such depth as to be
out OF reach of ships. icebergs, &C., BY means
OF buoys or floats Under the buoy will be
attached an anchor or weight, to prevent the
cable from swinging from direct line. The
most important object contemplated by the
busys, however, is the facility they would
afford in finding and repairing a defect in
the cable, would be equivalent to its destruct.
ion. MIR. Hall does not consider this feature
essential, as the cable could be sunk to the
bottom between the stations.
Mr.. Halls project is a bold one, and if
possible to realize, would be a vast improve
ment on the method now proposed, even if
1t can be successfully put in operation, of
which there is some doubt. Not the least
important consideration is that one end Of