The Sun.
London, England, 1853-10-13 00:00:00

NAVAL INTELLIGENCE.

PORTSMOUTH, OCT. 12.
The Conflict screw steam-sloop has made another trial
to-day, in Stokes's :Vey of the boomerang propeller, the
invention of Colonel Sir T. Mitchell, Surveyor-General
•f New South Wales. Various experiments have lately
been made by the Conflict with the common screw, por-
tions of which have been cut off, until at the last trial
the surface left was reduced to that of the boomerang
blade. The forms of the blades are thus described :
That of the common screw consists of a sixth part of the
whole screw, or helix ; that of the boomerang traverses
a sixth part of the whole screw, or helix, diagonally, and
has much less surface and weight. It was the opinion
of some engineers that, if the blade of the common screw
were cut down so as to leave the same extent of surface
in the middle part as the Australian screw had in its
traversing blade, the effect would be as good. The re-
sult of the experiments have proved the reverse. The
common screw when deprived of 12 inches at each cor-
ner barely came up to the action of the boomerang
blade, and when cut down by the removal of 18 inches
more its action was less still. There evidently appears
an advantage in the oblique blade and leverage of the
boomerang, while its surface and weight are much less
than are those of the common screw, the vibration being
also less. To-day the wind was squally, its force vary-
ing from two to four on the beam. The revolutions of
the engines were 671, and the greatest speed attained
was in the last two runs at the measured mile, which
averaged 9.804 knots per hour, the greatest average ever
attained by the Conflict. In order to give an accurate
conception of the exact results of the trials of the com-
mon screw and the boomerang, we subjoin the results of
to-day's trial of the latter, and of three others of the
first-named, made on the 21st of September and the 6th
and the 7th inst., it being only premised that on the
21st of September the wind was a dead calm, and the
ship only just out of dock, where she had had her bot-
tom cleaned :

The Common Screw.—Trial of Sept. 21.
Time. Knots
per Hour. Average.
First run ... 6.22 ... 9.421
Second.... ... 6. 8 ... 9.783
Third ... 6. 5 ... 9.863 9.772
Fourth. 6 91 9 448
..„ .
Fifth ... ... 5.47 ... 10.375
Sixth ... ... 6.31 9.230
The Common Screw Cut.—Trial of Oct. 6.
Time. Knotsper Hour. Average.
First run ... 5.40 ... 10.5881
Second.... ... 8.10 ... 7.3461
Third ... 5.44 ... 10.465 8.975
Fourth 7.55 7.579
Fifth ... 5.46 ... 10.404
Sixth ... 7.30 ... 8.
The Common Screw Cut.—Trial of Oct. 7.
Time. Knots
per Hour. Average.
6. 5 9.863
7.11 8.352
5.44 ... 10.465

First run
Second ...
Third ...

9.178

Fourth ... 8. 7 ... 7.392
Fifth ... ... 5.22 ... 11.180
Sixth ... ... 8.36 ... 6.977
The Boomerang Propeller.—Trial To.
Thne. Knots
per Hot
5.22 ... 11.180
7. 8 ... 8.413
5.22 ... 11.180
7.14 ... 8.295
5.28 ... 10.975
5.57 ... 8.633

day.

First run

Second
Third
Fourth
Fifth
Sixth

Average.

9.742

PLYMOUTH, OCT. 12

We have advices from Bermuda to the 13th of Sep-
tember, giving a fearful account of the fatal progress of
yellow fever in that island. It first made its appearance
on board the convict hulk Thames, stationed at St.
George's, and soon went through the whole ship's com-
pany, there being no hospital ship to receive the sick.
It very soon reached the troops in garrison and the
townspeople. How long it would continue was uncer-
tain, as there was still a month or six weeks of hot wea-
ther to look forward to, and heavy rains were setting
in in succession to an exceedingly hot season. It is
stated that the Thames is beached at St. George's, under
the Barrack-hill, where she has continued imbedded in
her own filth for eight or nine years, without the slight-
est attempt at keeping her from the accumulation of
filth. The immediate cause of the fever is ascribed to
the fact that six weeks previously a severe gale occurred,
in the course of which the Thames shortened her heavy
chain moorings ' • they were consequently permitted to
work in the filth in which she was imbedded until the
whole surrounding atmosphere was poisoned with the
effluvia, and sickness was the consequent result. The
Weymouth (another hulk) has been taken down to St.
George's, and the survivors removed into her from the
Thames.

The _Bermuda Royal Gazette of the 13th of September,
gives a list of the deaths during the last five or six days
of August. It amounts to 81 persons, 40 of whom were
convicts. Among the fatal cases is that of Lieutenant
A. G. Woodford, 56th Reciment. Of this regiment 106
were sick, and 9 men, 1 officer, 4 women, and 2 children
had die Of the 205 convicts only 25 have escaped the
fever, and 50 have died. The Gazette says that the
fever was less intense.

The mail-boat Spray, Captain Hunter, arrived at Ber•
muda on.the 11th of September, 11 days from Halifax,
bringing dates from England to the 20th of August.
The ship Emerald Isle, 537 tons register, Captain
Pellatt, under charter by the Emigration Commission-
ers, which arrived at Plymouth on Sunday, sailed for
Adelaide at 2 yesterday afternoon. She embarked here
193 statute adults, viz., 34 married couples, 7 single
men, 92 single women, 22 boys, and 30 girls under 14
years, and 7 infants. Some of these were selected here
by Mr. J. B. Wilcocks, emigration agent, through whose
active exertions the Emerald Isle received such quick
dispatch. The owner, Mr. D. Smith, is gone out in her.

WOOLWICH, OCT. 12.

APPOINTMENTS.

Master—George Johnson (1830), from the Boscawen,
70, guardship in ordinary at Chatham, to command the
Apollo troop-ship at Sheerness.
Assistant-Engineer—Henry I. Sones, of the 3d class,
is promoted to the 2d class.
Masters' Assistants.—Samuel M. Spry, and Thomas
R. T. Quinn, have received their first appointments.
The Tyne storeship, Master Commander Peter Wel-
lington, is to be.paid off at this port on Saturday next.

THE CHANNEL FLEET.—The screw squadron, under
command of Commodore Martin, were lying off the har-
bour, south of the Old Head of Kinsale, on Saturday,
awaiting directions to join the Channel fleet at Spithead ;
but dispatches forwarded from the Admiralty by the
Highflyer, it is said, countermanded those orders. Her
Majesty's screw steam-frigate Highflyer, 21 guns, Cap-
tain Moore, which arrived on Friday in Queenstown,
took up the mail for the screw squadron, and left on
Saturday. It consisted of G,OOO letters for the officers
and men of the fleet. Her Majesty's screw steam-ship
Ajax, 58 guns, Captain Warden, will leave Plymouth on
the 18th, for Queenstown, and relieve her Majesty's
steam-ship Terrible, 21 guns, Captain M'Cleverty. Rear
Admiral Carroll's flag will be transferred to the Ajax on
arrival.—Cork paper.