The Sun.
London, England, 1865-09-23 00:00:00

Naval and Military Intelligence.

The ironclad frigate Bellerophon, 16, 1,000-horse
power (nominal), resumed, and brought to a con-
clusion, her official full-boiler trials of speed at the

measured mile, Maplin Sands, yesterday, the condi-
tions under which the trials were made on this occa-

sion being far more favourable than on the previous
day. Owing to various circumstances, the causes
of which became apparent yesterday, the engines,
although satisfactorily performing their work, could
not drive the frigate through the water during the
preliminary trials on Thursday at a greater speed
than a little over 13 knots per hour. During the
trials yesterday, although this speed was exceeded,
it was nevertheless not what had been anticipated by
her designer and builders. The officials who con-
ducted the trials left Chatham Dockyard at nine
o'clock yesterday morning in the paddlewheel steamer
Adder, Mr. W. Blakey, Master-Commander. These
included Mr. Reed, Chief Constructor of the Navy ;
Mr. Dinnen, Inspecting Officer of the Steam Branch ;
Capt. Tatham, of the Bellerophon ; Capt. Stokes,
Queen's Harbour-master ; Mr. Baker, Chief Engi-

neer and Inspector of Machinery ; Mr. Tucker,

Inspector of Machinery Afloat ; Mr. Thornton,
Master Shipbuilder, and the officials connected with
his staff ; Mr. Barnaby, Assistant Constructor of
the Navy, and others. During the night the Belle-

rophon had received about 100 tons of the best Welsh
coal in her bunkers, one cause of the unsatisfactory
nature of the results, as regards her speed, on the
occasion of her trial or. Thursday being the inferior
quality of the coal supplied to her. On the Bellerophon
being reached at her moorings near Saltpan Reach,
at the entrance to Chatham harbour, she was ready
with her steam up, and after receiving Capt. Ran-
dolph, commanding the Steam Reserve, and the
other officials on board, she at once steamed
towards the Nore with her head laid for the
Mouse light. The firm of Messrs. Penn and Son, the
makers of the engines, was again represented by Mr.
Matthews, and the machinery during the day's trial
was under the management of Mr. Wigzel. The
weather yesterday was all that could be desired for
the trial, the wind, which on Thursday was blowing
half a gale from the north-westward, having mode-
rated to a force of between 2 and 3. At this time the
frigate's draught of water was slightly in excess of
that on the previous day, her forward draught being
16ft. 6in., and that aft 23ft. 6in. ; pitch of screw,
21ft. Bkin. ; diameter, 23ft., with the upper edge out
of the water lft. lliin. On running down past the
Nore the engines were found to be doing their work
most satisfactorily, there being abundance of steam,
although, from causes which soon became evident, the
screw could not be made to revolve more than 58
times perminute, which appeared to be the maximum
The vessel's displacement was 5,630 tons, or less than
1,000 tons of her true displacement when at her deep
draught. With all the attendant favourable cir-
cumstances stated, the Bellerophon was placed on the
measured mile for her full speed trials, and seven
runs were taken, with the following results :—First
mile—time, 5 minutes ; speed in knots, 12.000 ;
steam, 221 b. ; vacuum, 26iin. ; revolutions of screw,
57. Second mile—time, 3 min. 57 sec; speed, 15190
knots ; steam, 221 b. ; vacuum, 26in.; revolutions of
screw, 58. Third mile—time, 4 min. 59 sec. ; speed,
12.040 knots ; steam, 231 b ; vacuum, 26in.; revolu-
tions of screw, 56. Fourth mile— time, 3 min. 56 sec;
speed, 12.254 knots; steam, 241 b. ; vacuum, 25in. ; ' e-
volutions, 58. Fifth mile—time, 4 min. 56sec. ; speed,
12162 knots ; steam, 2411 b. ; vacuum, 26in. ; number
of revolutions, 57. Sixth mile—time, 4 min. 1 sec. ;
speed, 14.938 knots ; steam, 241 b. ; vacuum, 26in. ;
revolutions of screw, 58. Seventh mile—time, 4m. 47
sec. ;' speed, 12.543 knots ; steam, 241 b ; vacuum,
26in. ; revolutions, 57k. Rejecting the first runs, so
as not to interfere with the calculations, the first
means of the above figures will be 13.615, 13.647,
13.708, 13.550, and 13.741 knots ; and the second
means 13.631, 13.677, 13.629, and 13.645 knots
per hour. With regard to the fact of the Bellero-
phon not having made a minimum speed of 14 knots
per hour on her trial, as was intended by her de-
signer, the causes must be sought for in various
causes. Chief of them is undoubtedly the character
of the screw. When the Bellerophon was designed
it was never intended to fit her with a four-bladed
screw only a little smaller than that supplied to the
Minotaur, which is 100 ft. longer, and driven by
engines of one-third greater horse-power. The
mistake made in this respect was painfully apparent
during the trials yesterday, the engines, although
working to their utmost, being only capt.ble of driv-
ing the monster screw at a maximum rate of 58 per
minute, although it was always intended that the
Bellerophon should be furnished with a screw pro-
pelled at the rate of 70 revolutions per minute.
The pitch, too, was found after the first few
minutes' steaming to be bad. Under all the com-
paratively unfavourable circumstances, therefore,
the trials yesterday will allow a fair estimate to be
also be necessary vtiilethmaa
screw
chiner
machinery
adapted d
in
no
thheer
vessel
formed of what the Bellerophon will do when fitted
will antod
drive it.
character ofn
to set the new screw at a
pitch of about 20ft. to arrive at anything like satis-
factory results. There is no doubt whatever that
when the alterations now pointed out are effected
the Bellerophon can approach to, if o, not exceed, 15
knots per hour, her engines being all that can be
desired. At the close of the trials yesterday the
Bellerophon steamed up into Chatham harbour at
a rate of 10 knots an hour, a vessel of her size never
having entered the dockyard at such a rate before.
Cavaliere Givo Ant. Grassi, Luogotenente-Colo-
nello di Artiglieria ; M. Prato Cesare, Maggiore del
Genie Militaire ; Cavaliere Avv. Pietro Fenolio, and
other officers of the Royal Italian Army, arrived at
Portsmouth on Thursday from London, and, accom-
panied by Mr. H. Garratt, Italian Vice-Consul at
Portsmouth, visited part of the fortifications at
Portsdown-hill—forts Widley and Southwick, re-
cently inspected by Gen. Bixio. Every attention
was shown to the visitors. They went over part of
each of the works, attended by Lieut. Castle, R.E.,
who explained their plan and details of construction.
The boys under training on board her Majesty's