The Sun.
London, England, 1842-10-17 00:00:00

NAVAL INTELLIGENCE.
PORTSMOUTH, OCT. 13.—The Orestes, 18; Com-
mander the lion. S. J. Carnegie, was this morning
removed from her moorings by the Topaz hulk, and
hauled abreast of, but not alongside, the dockyard,
immediately opposite the Semaphore, for the purpose
of practically testing the efficacy of her lightning
conductors, by a series of-experiments by Snow
Harris, Esq., F.R.S., upon whose plan the conduc-
tors have been fitted up. She was moored about 100
yards from the jetty, between which and the ship,
about midway, a barge was placed containing a car-
ronade. A wire leading from the positive side of a
powerful electrical battery in the Semaphore was at-
tached to a cup of gunpowder, on her main truck.
Another wire, leading from the negative side of the
battery, was attached to the gun in the boat. A short
wire was placed on the touch-hole of the gun, and led
over the gunwale of the boat to the surface only of
the water, on the side nearest the Orestes. There was
no communication between the ship and the barge.
Prom the interesting and important nature of the
subject, there was a numerous attendance of naval
officers from every ship in the port, among whom
were Admirals Sir Edward Codrington and Hyde
Parker ; Captains Sir Thomas Hastings, Lord John '
Hay, W. Henderson, Codrington, Carnegie, Willis,
Hailowes ; the officers of the Austrian frigate Bel-
lona ; General Sir Hercules Pakenham, and a num-
ber of scientific individuals from all parts of the neigh-
bourhood.
Mr. Harris first briefly explained the artificial ar-
rangement of the Leyden jar, by which all the results
of lightning may be imitated, and performed several
interesting experiments illustrative of the definite
aetion and laws of electrical discharges. It had been
generally supposed that metals were attractive of
lightning in virtue of some inherent affinity for the
electrical agency. Mr. Harris combated this supposi-
tion, and. showed that the laws of electrical discharges
were reducible to mere resistance or distance—that,
in fact, the discharge through an imperfect circuit or
conductor, as an unprotected ship, merely picked out
such pieces of metal as happened to lie in a line or
lines of least resistance to its course. This was illus-
trated by passing an electric shock over small masses
of gold distributed fortuitously on paper ; some of
these were burned up, others remained untouched.
The arrangement for illustrating the action of the
conductors in the Orestes has already been described.
The object was to show that immediately an electrical
discharge reached the mast-head, it passed down
to, and was dispersed in, the water, by means
of the continuous line .of conductors. This was
proved thus :—The electric battery in the Sema-
phore was discharged ; the discharge passed
along the copper wire from the metallic plate on the
interior of the jar to the mast-head; its presence there
was rendered apparent by the ignition of the gun-
powder in the cup; it passed thence down the con-
ductor on the mast into the hull of the ship, and
along the conductors on the hull into the sea. That
it had arrived in the sea was proved by the ignition
of the powder over the touch-hole of the gun in the
boat, awl the consequent discharge of the gun, be-
cause the only means by which this gunpowder could
be ignited was the passage of the electricity up the
short copper wire which connected the touch-hole of
the gun with the sea ; so that not only must the elec-
tric fluid have arrived in the sea, but it must have
passed through it to this short copper wire in the
boat. It is almost needless to add, that so rapid is
the passage of the electric fluid, that the report of the
discharge of the battery, the ignition of the powder at
the mast-head, of that over the touch-hole of the gun,
and the report of the gun itself, appeared simulta-
neous, notwithstanding the great distance traversed
by the electricity, thus showing clearly and satisfac-
torily that the instant the explosion arrived at the
main truck, that same instant did the conductors clear
it of the ship and transmit it to the water.
Several experiments were then made to prove that
the principle held good in the case when the top-
masts and top-gallant-masts were struck. These
were very conclusive, the electrical current followed
the continuous line without at all diverging to those
portions of the conductors, which by the striking
of the masts were placed in a position out of that line.
Wire rope-conducters were then considered, and
the several objections to them fairly and conclusively
stated. The danger of a man being killed in the
bight of such a rope, while striking the top or top-
gallant mast during a thunder squall, was most
clearly proved by a very neat experiment. Such a
case was represented by gold leaf on paper, and when
an electric shock was passed over the paper, the gold
was burnt up in the direction of the man, but re-
mained untouched round the bight of the rope.
The last experiment which was performed was with
a view to prove at once the complete protection
afforded by the continuous conductor, and the ap-
parent impossibily of the least action taking place on
metallic bodies out of it, thus practically refuting the
supposition of any lateral discharge taking place. A
model of a mast about ten feet in length was made in
parts, and an interrupted line of metal placed in the
heart of it. Percussion powder, which, it is well
known, will inflame with the least spark of electricity,
was placed between these interruptions. On the
outer surface of the mast a continuous conductor
was placed, the extremities of which were con-
nected at each end of the model of the mast with the
extremities of the interior and interrupted line
of metal. In order to make the experiment
more complete, bands of metallic leaf were made here
and there to surround the mast as hoops, together with
other metallic bodies which could enter into the mast
itself and touch the internal line of metal. An intense
shock of electricity was allowed to fall upon the upper
extremity of the mast, where both lines of metal were
in conjunction, with the view of discovering (since
the electric matter had thus, it may be said, the choice
of two lines) whether it would pass upon the metal
within, or whether it would be dispersed between the
two lines and pass down each, or whether it would
only pass down the exterior line, and whether, in
passing down that line, it could cause a lateral dis-
charge to enter the mast, or in any way to affect the
interior. This was a severe test, from the highly in-
flammable nature of the percussion powder, and it
succeeded perfectly. As long as the continuous ex-
ternal conductor remained perfect, the discharges of
electricity were innoxious ; when, however, the ex-
terior conductor was removed and a similar charge
was thrown over the model, the mast was blown to
pieces by the ignition of the percussion powder,_ evi-
dently proving that if the previous discharges had in
any way, or under any form, pervaded the interior,
this effect would have resulted in the very first instance,
In repeating the experiment of passing the electric
fluid through the Orestes, an accidental circumstance
fully proved Mr. Harris's theory, that metals of them-
selves are not attractive ; and that lightning will take
the most direct continuous way to arrive at its course,
The wire which led from the Semaphore to the cup
containing the gunpowder at the mast-he'f. of the
ship, was not properly placed—the bight, touching the
mast a few inches below the cup. The discharge,
therefore, instead of continuing along the wire to the
cup, was conveyed to the conductor at the spot where
oitfi
un-
exploded,
the bight touched the mast, and carried through the
ship, and thence by theseatothaet b
the at
mast-head where
the gun, leaving the gunpowder
exploded,
After I%lr, Harris had concluded his experiments,
Admiral Sir Edward Codrington said that after what
he had witnessed, he thought it but right publicly to
observe that he felt perfectly convinced of thhe. efficacyhf
veet oarns
and satisfactory
lr.
teHarris'sats plan,he
hw
otlfiethoeonceolnudsthat day
whad ich,
undergone, would no doubt be generallyyused through-
outy the navy.. All the other officers present were
equally gratified, and expressed their approbation of
the plan.
The Jaseur, 16, was commissioned yesterday after-
noon, by Commander W. Willis.
The Warspite, 50, Capt. Lord. john Hay, bent her
sails this morning, and wID go out of harbour next week.
The QM% Glendowertransport will leave Spit-
-444 to-morrow for Gibraltar, with convicts from
Woolwich and this port.
The Phatnix steam-frigate is hourly expected from
the Mediterranean.
whip at Spithead—Owen Glendower.
Ships in Harbour—St. Vincent, Victory, Excel-
lent, Warspite, Orestes, Jaseur, Bellona (Austrian),
Royal George yacht, Echo steamer, Java transport.
WOOLWICH, OCT. 14.—The Ariel steam-vessel,
Master Commander L. Smithett (acting), left Wool-
wich on Tuesday to resume her duties on the Dover
station. .
The Sindbad arrived on Wednesday from Ports-
mouth,
The Lightning, steam-vessel, Lieutenant-Com-
mander Falmouth arrived on Thursday from Plymouth._
c
milder G. Snell, who has not yet been superseded,
although appointed to the Nautilus, tender_ to the
Royal George yacht, left Woolwich yesterday with
Monsieur Clement and Mr. Joseph Large, one of the
foremen of the yard, to act as interpreter during the
experiments ordered to be made by the Lords of the
Admiralty, withapparatus invented and fitted on board
the by M. Clement, to ascertain the speed
9x
determine the heat of the water in the
thl:, Lightning,
ng
radeeteepr, to a
hailers, and enable navigators to discover when they
are within 15 miles of an iceberg, and furnish'ngs
sure indicator of all sudden changes front deep ° a
shallow water. The first is named the Str(iluloi
o
Monsieur CllPs
title given to a substitute for the common I
in the
has been approved of the French Ad which
t.,T and
introduced into, several of the finest
Royal Navy of France.
clasoribed the invention 0a folio in
has
copper ball, against which the" 11°1Ic'w
is attached to a moveable plug of watK, Rots,
the
which slides in a copper tube same metal,
centre of the vessel to the ke2l, passing through the
tached a lever, which, by To this plug is at-
acts on a second lever, placed means
of a vertical rod,
on the deck of the ves-
sel, and communicating with
a spring; the tension of
the spring constitutes an equilibrium with the pres-
gu" o e water °II the ball and
serves to measure