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-
spected, 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
board the Blenheim, 56, screw-ship, Captain Henderson,
C.B, at Spithead, are the invention of Mr. Thompson,
late surgeon of the Odiu 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
book. It is said this night telegraph 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 harbou.
Mr. Brown, master of the Agincourt, depeit-ship of
the ordinary, with a party under his charge, embarked
yesterday in the Confisnce steam tender, and sailed
from Devonport for Liverpool, to navigate the *Bacchus
to the former port.
A proposal has been made to the Admiralty to substi-

tats -Minell's screw moorings at Woolwich for the or-
dinary moorings.
Apollo troop-ship, Commander Rawstorne, 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 is nearly ready for service, and will
probatly go to Spithead about Monday next.
Linnet, 6, packet-brig, Lieut.-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 Devonport in charge of the master of the flag-ship
at Sheerness, with 2,5 seamen riggers from Chatham, and
25 from Sheerness.
Niger screw sloop-steainer, Commander Heath, em-
barked the mails f it. the coast of Africa on Tuesday, and
sailed from Devonport the following morning.
Poictiers, 72, ordinary guard ship, Captain Richards,
CB., is to be put out of commission on the 30th inst.,
and the Cumberland, 70, fitting as ordinary guard ship,
will hoist the pendant on the 31st. The officers and me❑
of the Poictiers are to be turned over to the Cumber-
land, which ship has got her main deck and quarter deck
and forecastle guns on board. 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 progressing in her rigging; her topmasts are fidded,
although as yet she has but tow men. Seamen do not
like large ships, and as there are such a number of stea-
mers fitting, she will not get her small complement of
seamen till these are manned. The Vengeance will be
completed by the dockyard by the 31st.
SUPERA.NNITATIONS.—The following workmen have
been superannuated at Chatham dockyard:—James
Thompson, oar-maker; Richard Moss, shipwright; Wil-
liam Virlander and Samuel Endell, sailmakers, on pen-
sions of 241. per annum each.

ADMIRALTY SURVEY OF THE BLACEWATER 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 :—" I have the honour to inform you that
in the river 131ackwater. between Yougbal and Lismore,
a distance cf nineteen miles, there are altogether no less
than thirty-four fishing-weirs; four below the wooden
bridge near Youghal, and thirty above it. Many of
these weirs appear to me to be very objectionable,
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
up with wickerwork, and therefore admirably adapted to
intercept and catch all matter carried in suspension, and
to cause its deposit. The weirs below the bridge are, I
consider, unobjectionable, as they are so placed as to
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 navigation. 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 scarcity in
the quantity of salmon so much complained of lately,
for they, each tide, catch enormous quantities of salmon
fry, which it is a common thing to see the country people
carry away in ba-kets full; a fact I witnessed several
times, and which I am assured by an intelligent person
conversant with the que,tion does a vast amount of
damage to the salmon fishery."
CANAL SCREW STEAM NAVIGATION.--OR Saturday
an experiment of an interesting character came off in
the presence of a considerable number of spectators, at
the Cans! Harbour, Portobello Bridge. Its object was
to test the applicability of a new screw-propeller to the
purposes of canal navigation. Many attempts have
been made from time to time to work canal boats by the
aid of steam-power, but hitherto they have been at-
tended with but a questionable success, the motive agent
being in every iustance applied so as to disturb the
water violently, and thereby cause injury to the banks
of the canal. To do a% ay with this formidable diffi-
culty Mr. O'Regan, 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 simplest character, and occu-
pies but a very limited space in the interior of the
boat, which has been built by
.Mr. O'Regan 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 worked 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 5f inches in diameter and of 10} 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, and four times as 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 took place. 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 far as the first lock.
ma
asitnitlal
igreater r
osupge ehdo,u
ta,
rateanThe
d mjoof
rufi. rvone:
Rymeibgl ea, senkpuewnr adhse or mut
arakdbe °es i ntaogt
secure an average speed
of six miles an hour, or even more. When Fulton's
grand experiment came off upon the Hudson River five
mqes an hour was an average rate of motion obtained,
yet even that speed was
by the enginenlooked u
now,
wn:na
lsy through
3 f a weoentd:
Mr. wonderful
achievement. There is, therefore, every reason to be-
lieve that, as time advances, a progressive improvement
will take
spaceakeplaoceccuinpietdheb
machinery
O'Regan's successful enterprize.
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 enginewen and firemen, is, according to
Mr. Olie2an's estimate, only 4d. 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, THURSDAY.—Captain Henry Chads
(son of Captain H. D. Chads, C. 13., of her Majesty's
ship Excellent), late of the Styx steam-sloop, which,
under his command on the Coast of Africa, made 27
prizes during about two years' commission, is selected as
the Flag-Captain to Rear-Admiral Fairfax Moresby,
C.R., the Lowly-appointed Commander-in-Chief on the
Pacific station. Captain Hamilton (to whom the ap-
pointment was offered) having declined it, Commander
James Prevost, son-in-law of .the Admiral, is the Com-
mander; Lieutenant Fairfax Moresby, of the Encounter
.
goreW ooriette, (49u 9f the Admir6l), xiag-Aoleu-