The Sun.
London, England, 1853-03-30 00:00:00

NAVAL INTELLIGENCE.

PORTSMOUTH, Mental 29.
Vice-Admiral Sir Thomas Cochrane, K.C.8., the Corn
mander-in-Chief at this port, visited the Highflyer, 21
screw-frigate, Captain Heathcote, yesterday afternoon,
after the departure of Rear-Admirals Berkeley and Fan-
shawe, and Captain Sir Baldwin Walker, the Surveyor of
the Navy. The Highflyer seems quite an object of interest
in the harbour. Her gallant captain will be superseded
on Friday by Captain Moore, son of the late Admiral
Sir Graham Moore, and nephew of the late Lieutenant-
General Sir John Moore. Captain Heathcote is super-
seded merely because he has not studied steam, whereas
Captain Moore took deep interest in the fitting of the
Highflyer for commission, so much so that it was ex-
pected he would have been appointed to her. His last
command was the Harlequin, 12, in the Mediterranean.
Captain Heathcote intends to qualify for the command
of another steam-ship by studying steam at Woolwich
dockyard.

Commander Joseph Bickford, recently promoted from
First-Lieutenant of the Cumberland, 72, flag-ship on the
West India station, and lately appointed Commander t•
the Albion, 90, in the Mediterranean, is appointed to
supersede Commander Kynaston in the Cumberland, the
latter' officer returning to England.
The London, 90, Captain Mundy, was inspected at
Spithead yesterday by Vice-Admiral Sir Thomas Coch-
rane.

The Cruiser, 14, screw-sloop, Commander the Hon.
G.. 11. Douglas, is refitting alongside the Blonde hulk.
She seems to have met with rough weather in her late

cruise.

No information has been received here yet regarding
the fate of the leaking and insufficiently-manned barque
Duncan Ritchie. Captain Haan, of the galliot Agneta
Juliana, parted from her when she was about 40 miles
south-south-east of Scilly, and, as the wind blew in that
direction, he considered she would go there. A cutter
was in company with her when last seen. The barque
registered 508 tons, and was 'launched at Aberdeen in
1843.

A court-martial, consisting of Rear-Admiral Arthur
Fanshawe, C. 8., President ; Captains Sir T. Maitland,
C. 8., of the Agamemnon ; E. H. Scott, of the Neptune ;
W. H. Henderson, C. 8., of the Blenheim ; J. Shepherd,
of the Victory ; G. W. D. O'Callaghan, of the Encoun-
ter ; Francis Scott, of the Odin ; W. Crispin, of
the Victoria and Albert ; E. Heathcote, of the
Highflyer ; and Mr. G. L. Greetham, Deputy
Judge-Advocate of the Fleet, assembled this morn-
ing at nine o'clock, on board the Sag-ship Victory,
in this harbour, to try a seaman gunner of the Excel-
lent, named Robert King, for desertion. Captain
H. D. Chads, C. 8., of the Excellent, prosecuted for the Ad-
miralty. The prisoner entered the Excellent on the 13th
of September, 1851, and, having acquired the gunnery
science, deserted on the 23d of December following.
He was apprehended in London on the 16th inst., by
William Cutler, a quartermaster of H.M.S. Crocodile, a
vessel stationed in the Thames for the reception of
volunteers for the navy, under the command of Lieu-
tenant Greet. Cutler finding the prisoner not provided
with a man-of-war certificate, or a mercantile regis-
tration ticket, took him before Lieutenant Greet,
before whom he admitted he was a deserter from the
Excellent at the time named in the charge. Lieu-
tenant Greet sent him down to this port, where Cap-
tain Chads and the master-at-arms of the Excellent
recognised him. The evidence established the charge.
The prisoner offered no defence, and threw himself on
the mercy of the Court, but called upon Captain Shep-
herd, one of the members, to speak as to his character,
he having served with that strict officer in H. M. S.
Inconstant. Captain Shepherd at once testified as to
his character having been " very good" during the time
lie was in his ship ; and The prisoner must have been a
deserving, good man to have merited that testimonial at
his (Captain Shepherd's) hands. In consequence of this
testimony the Court only awarded the prisoner twelve
months' imprisonment in the County Gaol at Win-
chester.

SHEERNESS, MARCH 29.
The Conquestador, 50-gun frigate (razeed from a 74,
and one of the advanced ships), has this day been
brought down from her moorings and taken into the
fitting-basin to be prepared for immediate commission.
The African and the Myrtle, steam towing-vessels left
here to-day for Chatham, for the purpose of towing the
screw steam-frigate Imperieuse, 60, Captain Rundle B.
Watson, down alongside the cool depot Fortitude, where
she is to take in 500 tons of Welch coals preparatory to
her departure.

WOOLWICH, MARCH 29.
APPOINTMENT.
Second Master John W. Read to the Prince Regent,
90, at Plymouth.

IMPROVEMENTS IN EXTRACTING GOLD AND
SILVER PROM THEIR ORES ( BAGGS' PATENT).

These improvements, but recently introduced, and
already adopted by some of the leading gold companies,
are not based upon any untried or theoretical notions
with regard to the extraction of the precious metals, but
are founded upon the well-known results of extensive
practical experience. Mercury is used in these arrange-
ments as before, but under circumstances eminently cal-
culated to extract the gold or silver with great rapidity
and completeness. In the ordinary process of amal-
gamation the two objects aimed at are—lst, the sepa-
ration of the mercury into innumerable small globules,
so as to present an extended surface for the exercise
of chemical attraction ; and, 2dly, to aggregate these
globules into one mass, and so separate the metal from
the quartzose debris which has been stripped of its auri-
ferous treasure. These two operations, as at present con-
ducted, consume a very great amount of time in the first
place ; and they are always attended with a considerable
loss of gold, as well as of mercury, from the difficulty of
fulfilling the conditions upon which the success of
the process depends. In California, where the sys-
tem of gold mining is extensively practised, shaking-
tables are employed, which require to be made with the
greatest exactitude, to produce anything like a profitable
result. But in every instance the operation is tedious, and
the result imperfect, and attended with loss. If gold,
like iron, could only be endowed with the property of
attracting and being attracted by some subtle force
operating at sensible distances, like that of a magnet,
the process of extraction would be comparatively easy ;
or if, without destroying the liquidity of mercury, we
could only cause it to assume the form of a sieve (which
appears at first sight to be a physical impossibility), and
then cause the material upon which we are operating to
pass over and over again through the meshes of that
sieve, it is obvious that we should realise the de-
sideratum of an enormous surface of action, and
multiply the points of contact between the coin-
' bining substances to an extent hitherto deemed un-
attainable. Now, every chemist knows that when a.
fluid body acts upon a solid, the action is limited to the
points of actual contact ; so that if a globe of mercury
were made to act upon gold quartz, the surface would be
exercising its power of affinity, while the interior of the
sphere would be practically inactive ; and though we
are aware that the globules of mercury, in the ordinary
process of amalgamation, are mechanically small, yet,
chemically considered, they are very large, and hence
there results a great waste of power, time, and material.
The idea of a mercurial sieve, to which we have
just adverted, forms the leading feature of the
present invention. Taking into account the num-
ber, length, and diameter of the cylindrical wires
which compose each of the sieves, the total service pre-
sented to action is upwards of 160 superficial feet ; and
if we only suppose the barrel to make 100 revolutions to
begin with, in the short time so occupied the materials
which it contains will be brought into close and intimate
contact with no less than 16,000 square feet of mercuri
alised surface a surface incessantly renewed by the
percolation of falling mercury, and as continually
presenting its powerful attraction to the fine parti-
cles of gold which are made to pass through its
meshes. Considering the nature of these arrangements,
we are not surprised at the statement of the inventor,
that the process of amalgamation may thus be accom-
plished in one-tenth of the time usually occupied in effect-
ing it, and that 90 per cent. of the mercury ordinarily
required is saved. Not that a smaller per centage of this
metal is added to each charge, but that ten consecutive
operations may be performed in the time now occupied
in the reduction of a single charge ; so that a given
weight of mercury does ten times the work it has done
hitherto. In a cheaper form of amalgamation, under
this patent, the sieves are dispensed with, and replaced
by amalgamated balls of copper, thrown loosely into the
cask with the quartz ore, and a proper quantity of
metallic mercury. . _

When the necessary combination has been effected
by either of the above means, it becomes necessary to
separate the auriferous amalgam from the refuse mate-
rial with which it is now associated. This is a pro-
cess which commonly occupies time, and to take silver
as an illustration, it is the practice in the European
an amalgam of this metal from the
rock, methodt of producing
to
cause
the
barras
in
which the chemical union
has been effected to be reduced in speed to about 8 re-
volutions per minute, instead of making, as previously,
from 20 to 25. By this means the- minute globules o
mercury are aggregated into one mass ; but the opera-
tion is not effected under two hours, and even then a
portion of the metal is lost.
In addition to the Alliance Company, these improve-
ments have been already adopted by the Anglo-Califor-
nian and Anglo-Australian Gold Companies ; and great
results are looked forward to from their application in
'fa California and the antipodes•—Mining Journal of tSa-
turday.

SHIP-BUILDING ON THE CLYDE.—There are at present
100 vessels in course of construction on the Clyde, and
of these only six are timber-built—all the rest being
built of iron. It is also notable that these iron vessels
consist both of steam and sailing vessels, though the
former class preponderates. The aggregate tonnage
of the ships now in course of construction on the Clyde,
amounts to upwards of 60,000 tons. The engines of
the steam Part of this great fleet have an aggregate of
more than 14,000 horse power. The probable value of
the whole, though the estimate is necessarily inexact,
cannot be much short of two millions sterling ! Yet in a
few mouths, this enormous amount of shipping will be
off the stocks, and its place supplied by a new produc-
tion, equally valuable. The number of workmen em-
ployed in building the vessels and making the machinery
is about 15,000. The number of hands employed in
raising the raw materials from the basin of the Clyde,
within a circle of 20 or 30 miles, for these and similar
great works, is still more immense. Another most grad
tifying feature of the ship-building trade of the Clyde is;
that the employers in nearly all the establishments were
working men themselves within the last 30 years. Most
of them had attained the period of middle life before they
turned their attention to iron boat-building at all. The
men are not only the architects of their own fortunes,
but the creators of a new branch of industry.—Nortili
8ri444 Mag.

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