The Sun.
London, England, 1850-08-23 00:00:00

NAVAL INTELLIGENCE.

The Surveyor of the Navy, Captain Sir Baldwin
Walker, K.C.8., is staying at Brighton.
The vacant appointment of inspecting-commander of
the coast-guard, caused by the death of Commander
Merritt, has been given to Commander James Archi-
bald Macdonald (1848).
Commodore Lord John Hay, C. 8., mustered, in-
spcc.ed, and paid advance, on Wednesday, in Plymouth
Sound, the Thetis, 36, Captain A. L. Kuper, C. 8., and
the Salamander, 6, steam-ship, Commander Ellman,
these vessels having previously been swung for the
adjustment of their compasses by the Queen's harbour-
master, Mr. Thompson. The Thetis, as we have stated,
is ordered to Spithead, and the Salamander has drawn
her charts, and was to proceed yesterday to Rio, the
Cape, and the East Indies.
The new signal-lights now under a course of trial on
heard the Blenheim, 56, screw-ship, Captain Henderson,
C. 8., at Spithead, are the invention of Mr. Thompson,
late surgeon of the Odin steam-frigate, and are intended
to be worked as a telegraph at night. The different
positions of the lights represent the different numerals,
and are to be deciphered by the common day tel, graph
book. It is said this Light tel.-graph can be perfectly
made out at the distance of two miles and a half. It is
now being worked between the Blenheim at Spithead,
and the Victory in Portsmouth harbor.
Mr- Brown, master of the Agincourt, del 6t-ship of
the ordinary, with a party under his charge, embarked
yesterday in the Confiance steam tender. and sailed
from Devonport for LivLrpol, to navigate the Bacchus
to the former port.
A proposal has been made to the Admirslty to substi-
tute Mitcriell's screw moorings at Woolwich for the or-
dinary moorings.
Apollo troop-ship, Commander Ravrstorne, has been
docked. She has to have new copper. Her old copper
rips off like brown paper. She is to be got ready to
leave for the West Indies by Sept. 10.
Fox, 42, Commodore Lambert, has hauled of along-
side her hulk. She it nearly ready for service, and will
probatly go to Spithead about Monday next.
Linnet, 6, packet-brig, Lie ut.-Commander James, was
taken out of No. 5 dock at Devonport on Tuesday ; and
the Portland, 50, taken in the same tide.
Magicienne steam-sloop,: left Chatham on Wednesday
for Devonpert in charge of the master of the flag-ship
at Sheerness, with 25 seamen riggers from Chatham, and
25 from Sheerness.

Niger screw sloop-steamer, Commander Heath, cm-
barked the mails f the coast of Africa on Tuesday, and
sailed from Devonport the following morning.
Po!ctiere, 72, ordinary guard ship, Captain Richards,
C. 8., is to be put out of commission on the 30,ti
and toe Cutabet Lind, 70, fitting as ordinary guard ship,
will hoist the pendant on the 31it. The officers ;lad men
of the Poietiers are to be turned over to the Cumber-
land, which ship has got her main deck and q larter deck
and fjrecastle guns on bJard. The lower deck guns are
not to be put on board.
Tiger steam-sloop has been masted at Chatham, and
taken into dock, to be fitted for service at sea, previously
to being sent round to Portsmouth to form one of the
reserve squadron.
Vengeance, 84, 'Captain Sir Henry Blackwood, has
had her old copper stripped off. She is undergoing a
thorough caulking previous to receiving new copper. She
is progressinz in her rigging; her topmasts are fidded,
although as yet she has but few men. Seamen do not
like large ships, and as there are such a number of stea-
mers fitting, she will not got her small complement of
seamen till these are manned. The Vengeance will be
completed by the dockyard by the 31st.
SUPERANNUATIONS.—The following workmen • have
been superannuated at Chat Liam dockyard :—James
Thompson, oar-maker; Richard Mss, shipwright; Wil-
liam Virlander and Samuel Endell, sailmakers, on pen-
sions of 241. per annum each.

ADMIRALTY SURVEY OF THE BLACKWATER RIVER.
—Commander George A. Frazer, of the Sparrow, has
made a report to the Lords of the Admiralty on the ob-
structions to the navigation of the river Blackwater, in
which he says:—"l have the honour to inform you that
in the river Blackwater, bettet-eu Youghal and Lismore,
a distance of nineteen miles, there are altogether no less
than thirty-four tishing-weirs; four below the wooden
bridge near Youghal, and thirty above it. Many of
these weirs appear to me to be very objectionahle,
especially those extending from bights or bays, and
which are in every case carried to beyond the natural
low-water curve, and almost to the middle of the river;
they have accumulated deposit to such an extent as to
make their extremities the actual low-water mark. Most
of the Blackwater weirs are quite close, being basketed
twi
andck erw
catcho r ka,lalnmda therefore
eadmirably
suspension,adapted a
ntdo
consider, unobjectionable, as they aro so placed as to
itunopteewarciuteshpe its deposit.; The weirs below the bridge are, I
give a better direction to the scour, and, therefore, im-
provement to the channel or harbour water. I am of
,pinion that almost all weirs tend more or less to do
harm, although many may be so circumstanced as not
in any way to interfere with its ntivigatior. I do
not feel competent to offer an opinion as regards
their effects upon the fish of a river ; I may, how-
ever, presume to remark that the style of weir used
in the Blackwater being so very close, must tend in a
great measure, I think, to cause that great scarc-ty in
the quantity f salmon so much complained of lately,
For they, etch tide, catch enormous quantities of salmon
fry, which it is a common thing to see the country people
carry away in ha kets full; a fact I witnessed several
times, and which I am assured by an intelligent person
conversant with the question does a vast amount of
damage to the salmon fishery."
CANAL SChEw STEAM NAVIGATION.--Oa Saturday
sa experiment of an interesting character elm() off in
the presence of a considerable number of speetatore, al
the Canal Harbour, Portobello Bridge. Its object was
to test the applicability of a new screw-propeller to the
purposes rf canal navigation. Many attempts have
be .nmade from time to time to work canal beats by the
aid of s team-power, but hitherto they have been at-
tended with but a queAlonable success, the motive agent
being in every instance applied so as to disturb the
water violently, and thereby cause injury to the banks
of the canal. To do away with this formidable diffi-
culty Mr. O'R-gan, the projector of the improved
screw-propeller we are about to describe, brought his
practical knowledge of machinery into requisition,
and with a degree of success which could scarcely
have been looked for. The machinery connected with
the propeller is of the aimplest character, and occu-
pies but a very limited space in the interior cif the
boat, which hos been built by Mr. O'itegen himself,
without the least assistance from any quarter, at an ex-
pense of 3301. It resembles, in size, shape, and general
appearance, the ordinary iron fly-boats employed on our
canals, and which have hitherto been worktel by horses
only. The steam is generated by a vertical tubular
boiler, to which an engine of six-horse power is attached.
The cylinder is 5i inches in diameter and of 10i inches
stroke, the pressure being 501 b. to the square inch. A
screw, 2 feet 4 inches in diameter, and consisting of two
arms, is mounted in the stern, immediately behind the
rudder; attached to which is a horizontal axle of consi-
derable length, passing longitudinally through the bottom
of the boat, as near to the keel as practicable. A
driving band, worked by a large wheel, causes this•axle
to revolve with great rapidity-90 revolutions being
produced in each minute, arid four times us many

. ,
revolutions of the screw. The chief peculiarity is
the position of the axle and screw, the former of
these being placed extremely low down, so as to
enable the screw to work at a considerable depth
in the fluid, an arrangement which materially aug-
ments the propelling power, and at the same time
causes as little commotion as possible in the upper stra-
tum of the water. On Saturday, at half-post two
o'clock, the trial soak plus. The boat, laden with a
weighty cargo of passengers, quitted Portobello Har-
bour, and steamed her way bravely, at a speed varying
from three to five miles an hour, as tar as the first lock.
The journey back was made at a still greater speed, a
rate of five miles per hour being maintained throughout,
and Mr. O'Regan undertakes to secure an average speed
of six miles an hour, or even more. When Fulton's
grand experiment came off upon the Hudson River five
m les an hour was an average rate of motion obtained,
yet even that speed was then looked upon as a wonderful
achievement. There is, therefore, every reason to be-
lieve that, as time advances, a progressive improvement
will take place in the machinery now, through Mr.
O'Regan's successful enterpriz?,.
_

DC; space occupied by the engine is only 3 feet 4 by
2 feet 6, and the width of the boiler is about 3 feet. The
engine consumes 8 cwt. of coal per day, and the entire
cost of the propelling power, inclusive of fuel and the
wages of the enginemen and firemt,n, is, according to
Mr. O'Begao's eat mate, only 41, a mile—while the cost
per mile, where the motive power is supplied by horses,
is no less than Is. 91—Saunders' News Letter.
PORTSMOUTH, THURsDA.Y.—Cuptiia Henry Chads
(son of Captain H. D. Chads, C. ii., of her Msjoaty's
ship Excellent), late of the Styx stesa,:cop, which,
under his co:l,mnd on the Cos...t of Africa, made 27
prix's during about two years' commission, is s, letted as
the Flag-C ptsin to Rear-Admiral Fsitfax Moresby,
C. 8., the newly-appointed Commander-in-Chief on the
Paific station. Captain Hamilton
(to whom the rp-
pointment was offered) having declitvd it, Clmmsnd r
Jam us Prevost, so:.-:n-law of she Admiral. is the Corn
mender; Lieutenant Fairfax Moresby, of the Encount€r
screw coryttt7, (son of the Admiral), is the Flag-Lieu-