The Sun.
London, England, 1853-04-07 00:00:00

THE BOOMERANG PROPELLER

LIVERPOOL, WEDNESDAY.—Yesterday afternoon
trial was made in the waters of the Mersey of Sir
Thomas Mitchell's new mode of propelling ships by the
boomerang, in lieu of the common screw. The trial triP
was made in the Genova, one of Messrs. M'Kean ,
M'Klarty's Mediterranean steamships, the distance be'
lug from the Rock Light to the Crosby Lightship and
back. The boomerang is used in a similar way to the
ordinary screw, but its design and construction ale
widely different. The original idea was borrowed by
the inventor from the peculiar gyrations of the weapoll
used by the natives of Australia in its flight through
the air. That instrument is crescent shap
ed, but in-
stead of an arc, it has an elbow in the
middle. It
about 2 feet long, and about 2 inches broad, a quarter
of an inch thick, and is made of heavy wood. NO°
thrown in the air by the natives it describes two revola'
tions, one direct and the other rotatory. By the latter
motion it revolves round its own centre of gravity, 1.
enabled to survive the direct impetus with which it 14
sent up, and is made to screw back to the spot when
it was thrown.
This peculiarity suggested what is called " the hoorofs
rang propeller," which, in the course of the day,
described by Sir Thomas Mitchell. After many exPerl;
ments made for the purpose of discovering the best
ine3n.
of attaching a centre, so as to make the principle aPPI
cable to the propulsion of vessels, the various
practica
difficulties in the way were removed.
The elbow-shaped weapon of the savage gliding throtigt,h
the air shows how the difficulty of the centre may °_,e)
avoided; the cusps illustrate the mode by which engineel7
may regulate the circumference, while the general form °
the missile, in acting obliquely on the radius of the rota
tory motion, teaches how it is possible to embrace 01
columns of water at once with the least possible surface
and the least obstruction to the rotatory motion, but, AS
the same time, -with the greatest effect as a screw.
The great difficulty of testing the true value of the
invention has hitherto lain, and still continues to lie, in
the fact that screw-vessels are built with apertures too
narrow for its application in its entire and con] APlentef
form. It requires a space equal to at least
()pe-
tite height of the aperture. The only opportunity one-third
the
inventor has at present had for testing it— and this 3
very severe test—is by applying only mutilated portions
of it, relying on the more harmonious nature of its silL
face compared with the screw now in use and to
perfect freedom at the centre, which prevents it from
choking, and, consequently, gives it greater facility for
rotatory motion. So great is the mutilation necessary
to admit of a trial at all with ordinary steamers, that;
whereas the chief advantage of the boomerang propellee
is in its embracing two-thirds of the helix at once, th
two blades of the one used in the Genova were not ma's
than one-seventh each of the complete spiral, or ley
than one-third on the whole.
Another advantage in the boomerang is, that from the
convexity of one blade and the concavity of the other'
the water is prevented from being driven to the centre'
and thus choking it, as in the common screw, and dire°
steering is thus materially facilitated.
The severest test that could be applied was submit4.rea to yesterday. The pitch of the two mutilated portion)
was nearly double the diameter—i. e., the pitch was
feet 2 inches, and the diameter 12 feet 3 inches, so that
the working surface was five feet less than that of tPeci
common screw, against which it has been tried ; an
whereas the common screw weighed 62 cwt., the booloe'
rang was only 26 cwt.
Notwithstanding these adverse 0
circumstances, the
average speed obtained in slack water was from 9 co°
to 91 knots, under a pressure of steam of from 61b. , '
91b. ; a speed which several scientific gentlemen °ll board asserted was one knot faster than could hate
been made by the common screw under the same pre'
sure of steam.

In the course of the afternoon the visitors were ell'
tertained to dinner in the first-class cabin, Mr. Lamont:
of the firm of Messrs. M'Kean and M'Klarty, occuPYij!':
the chair. That gentleman, in the course of some a')
servations made after the cloth had been withdrawn,
regretted that complete justice had not been done to thl,
boomerang on the occasion, owing to the inability °.
the engineer to keep the steam up to a fair pressure 0).
101 b. He and the company he represented were, heir'
ever, so convinced of the great superiority of the boor;;
erang over the screw, that they were having one 0
their veesels prepared for the trial of the new propeller
e
in its integrity. Mr. Lamont also referred to the use
I n her , previousurhereas
svhoey
it with complete success in the last voyage of al
of English anthracite, in lieu of coals. They had tried
Livorno, having found that it was more serviceable, an
nlsr
v7egae
great
1 e:o i
aneEtsn
Britain
etrf
ae
iavcnnoo,
took up much less space.
ahgadesoltllli
consumed 12 tons 5 cwt. of anthracite. He thong"
because, if they could save a quarter of the consurat',.e.
ldaulftodiroenlianaysst
a the boomer'
voLefi thisivfl utoewerdlno,:uml drluefeccihrutehiairenteeedGea
consuming 1,500 tons of coal on her passage to Aus'
tralia, only required 1,000 tons she could accomplish
the whole distance without touching at St. Helena for
coals. The gain by anthracite instead of coal would,
in his opinion, be about 35 per cent., besides having the
gratifying fact that anthracite was not liable to spoil'
wncoeu,ldinsbteeatl.Pol i
taneous combustion.

DEATH OF LORD SKELMURSDALE.—We have to re'
cord the demise of this venerable nobleman, at Lathora
House, in his 83d year. His lordship sat in the House
of Commons from 1795 to 1828, when he was raised to
the peerage. He is succedeed by his grandson Edward,
eldest son of the late Hon. Richard Wilbraham, 1V1.17',
now in his 14th year. The Countess of Derby is the
youngest daughter.
CINCINNATI AND Sp. LOUIS RAILWAY._ The prospee-
tus of an issue of first mortgage bonds on the important
railway line in the course of construction between Chr
cinnati and St. Louis was published yesterday by
Messrs. George Peabody and Co. The length of the
road is 335 miles, and it is under contract to be Cour
pieted for 9,000,000 dollars by the Ist of July, 1854
Much of the undertaking is already finished, and VW°
divisions of it are to be opened on the Ist of January
next. The capital subscribed in the United States 18
about 6,000,000 dollars, and the bonds now offered are
for 2,050,000 dollars, or 410,000/. sterling. Their sell;
rity is that of a complete lien on the entire work, an:
they are to be redeemable in 1872, bearing meanwhile
per cent, interest, the holders also having the right to
conTert them into stock any time before the Ist ),:
January, 1857. A deposit of 10 per cent. is to be pal
immediately, and the remaining instalments on the 3t
May and Ist of September.

- -
SUICIDE BY OXALIC ACID.---Yesterday morning in
formation was forwarded to Mr. Langham, the Depot;
Coroner for Westminster, of the death of Ann Rawl'
son, aged 28 years, who resided at Old Boswell-court,
Carey-street, Lincoln's-inn-fields, who committed se::
destruction by swallowing a large quantity of oxalis
acid. It appears that the deceased had formerly °cow
pied a respectable position in society, having been the
daughter of persons who earned an honest livelihood-
Some time since she quitted her home in a fit of passiob
and finally became the paramour of a cabman. °I/
Monday night the deceased obtained a quantity of or
alic acid of the neighbouring chemists, and on her re'
turn took the poison. Her groans attracted the atten-
tion of the inmates, who instantly raised an alarm, whell
Dr. Digby, surgeon, was promptly on the spot, but:
notwithstanding his exertions, she expired in most elc
cruciating agony. No cause at present has been es,
signed for the rash act.