The Sun.
London, England, 1860-04-07 00:00:00

Lessee, Mr. JR,/

On Easter Monday will
ROUTE. Messrs. C. M-
pendale, Mrs. C. 359 cup on Thursday on board the screw
To coneludPivile, 90, Capt. K. Barnard, and she went
OF koYidmoaze into Plymouth Sound, where she

saluted the flag.
The sailing frigate Constance, 50, at Devonport,
is to be lengthened 40 feet and fitted with a screw.
The lower yards of the screw steamship Aboukir,
90, were sent down on Thursday.
Steam was got up on Thursday onboard the Espoir,
5, and she went outside Plymouth Sound on trial
for several hours.
The crew of the screw steamship Donegal, 101,
Capt. Henry Broadhead, were paid wage. s at Ply-
mouth on Thursday by Admiral Superintendent
Sir Thomas Pasley, K.C.8., and they obtained
leave of absence.
A letter has been received at Plymouth from the
screw steamship Orion, 91, Capt. John B. E. Frere.
It is dated Naples, March 13, and states that she
the
10th. Malta on the 7th, and arrived at Naples on
10th. During the passage she sprang a leak, and
had four feet water in the hold. As the repairs
cannot be accomplished at Malta, she will have to
come home. The leakage is said to be increased,
if not caused, by the working of the machinery, in
consequence of which she will return under canvas
only, and may be expected shortly at Plymouth.
The Castor, 36, sailing frigate, was towed on Thurs-
day afternoon by two steamers from Chatham har-
bour to Pinope Reach, were she anchored for the
night. She was to have left yesterday for Green-
hithe to take up her position at the moorings pre-
pared for her in the Thames, where she will be
stationed for a time to serve as the receiving-ship for
the Naval Coast Volunteers. She has her main-
deck guns on board, consisting of 18.32 pounders,
each of 56 cwt., and Oft. bin. long.
The Galatea, 26, screw frigate, 800 horse-power
(nominal), has been undocked at Chatham, and will
proceed to Sheerness to join the steam reserve at
that port.
The paddle-wheel surveying vessel Bann, James
S. Wells, master, discharged her powder in Ply-
mouth Sound on Thursday, and went into Hamoaze
to have defects made good.
Her Majesty's steam storeship Rhadamanthus,
Master-Commander Frederic Sturdee, having un-
dergone an entire renovation of her engiaes and
machinery in the river, off Woolwich dockyard, and
a thorough inspection of her boilers, is ordered to
steam down the river on a trial of her speed, and
verification of her precise consumption of fuel under
a supply of ordinary steam alone. Their Lord-
ships have signified their desire that special care
shall be taken to notify minutely every circum-
stance relative to the abovenamed particulars,
and that a report may be promptly forwarded
thereof to the Board of Admiralty foi their consi-
deration. The order further adds that the Rhada-
manthus immediately after her trial will be fitted,
at the cost of Government, with the patent improved
apparatus of the Hon. John \\Tethered, a member
of the United States Congress, for the supply of
combined or ordinary and superheated steam
mixed, and which, it is stated, cannot fail, as proved
by previous experiments, to increase the power of
the engines, and also economise the consumption
of fuel from 30 to 50 per cent. The mode adopted
in carrying out the system is to attach another
stead pipe to the boiler for conveying the steam to
be superheated to pipes, or other contrivances
placed in any convenient form near the fire, or in
the uptake near the chimney of the boiler, or in a
separate furnace; the superheated steam being
added to the ordinary steam at or before its en-
trance into the cylinder. In its passage through
the superheating apparatus, that portion of the
steam is raised by the waste heat to a temperature
of 500 deg. or 600 deg. Fahrenheit. The heat thus
arrested is conveyed to and utilised in the cylinder
by its action on the other portion of steam from the
boiler, which is more or less saturated, according
to circumstances. The combined steam is issued ist
the cylinder at from 300 deg. to 450 deg. Fahren-
heit, instead of at the low temperature at which
steam is generally employed. The effect of using
the two kinds of steam has already proved the fact
that the superheated steam yields a portion of its
excess of temperature to the ordinary steam, con-
verting the vesicular water, which it always con-
tains, into steam, and expanding it several hun-
dred-fold; while, at the same time, the ordinary
steam yields la portion of its excess of moisture,
converting the steam gas into a highly rarified
elastic vapour—in other words, into pure steam at
a high temperature. Repeated endeavours have
been made to employ steam simply dried or super-
heated, all of which have been partially abandoned,
as, owing to the high degree of temperature neces-
sary, the lubricating materials have dried up, and
the packing and rubbing parts of the machinery
have been destroyed, and the temperature of the
steam in the cylinder has been found to be beyond
the control of the engineer. It is asserted that
Mr. Wethered's improvement, now about to be
adopted by the Admiralty, arose from the above-
named difficulty.
A further discharge of 75 mechanics and labourers
will take place at Chatham dockyard this afternoon,
including 20 shipwrights, 40 labourers, and 15
smiths, joiners, sawyers, and other mechanics. In
consequence of the great extent to which the esta-
blishment at Chatham was recently increased, there
ere still about 600 mechanics and labourers to be
discharged before the number of workmen in the
dockyard has been reduced to that ordered by the
Admiralty for the present year.