The Sun.
London, England, 1862-09-01 00:00:00

Revolutions

Engines.

1 3 38 16.514
(JCS
2 4 57 12 121 54
3 338 16514 Equal to 51f
4 450 12.413 the Black Prince's. 53i
5 3 43 16.142 55
6 447 12.543 53}
Mean speed of the six runs, 14,354 knots.
By a comparison of the two means it will thus be seen
that there is a difference of speed against the Black Prince
of 1'037.

In seeking for the cause of this difference several may be
found, which, together or separately, will give a satisfactory
reason for the apparent loss, although it, at the same
time, will leave the Warrior as undeniably the faster
ship of the two. There is a difference in the pitch
of the two screws of about seven inches, and, with the Black
Prince altered to this extent, it is calculated that she would
increase the revolutons of her engines from her maximum
rtite of 52 to 54, or perhaps 55, the maximum of the War-
rior's, which would give her at the same time an increase of
speed. Again, the Black Prince had on Saturday a mean
draught of water of 7f inches over that of the Warrior on
her trial, the former drawing 26ft. forward and 27ft. 2in.
aft, while the latter only drew 25ft. Gin. forward and 26ft.
Sin. aft, This would necessarily add to the Black Prince's
displacement and to the amount of resistance she would
have to overcome in passing through the water. It will also
be in the recollection of all those interested in such matters
that before leaving the Clyde the Black Prince grounded
and heeled over considerably, causing fears at the time that
she had somewhat strained herself. We have before alluded
to the slight disturbance in her upper port line, and there
is little doubt that she has dropped slightly at each end
since receiving her weights on board. If the form of her
bottom is at all altered, here alone is a sufficient cause to
account for the loss of a knotper hour of speed. Looking at
all these causes, however, a selection can only be fairly
made of the 71 inches extra displacement, and the difference
Black defeat. This extra in the pitch of the two screws
Prince'sas the true sources to which
deserves. Soule consideration. No rea-
son any certainty of its success, for
must be ascribed the
draught of water exceeding that of the
dis-
placement,soncanbe ashosiwgnevedert
auxiliary engines exceeded in weight that of
35 tons of armour plates, more than compensated.
but for this the Warrior's Rifle Tower,
The bottom of the Black Prince must therefore be sharper
must be thrown out of proper form,or her
thetwWthhi
aetanhrßlrtiaihltoatsetrce:r HaFa r
rhe 1:r
in::
bottom plates must be considerablythe heaviest. Over so vast
surface the 32d part of an inch would make a great difference
to the ship's weight. One thing is certain—the loss of a knot
per hour of the ship's speed under steam is not due to her
machinery, which fully maintained, by its working on
Saturday, the reputation of the emin9nt firm by whom it
was manufactured. The loss, then, is due, in some form,
to the ship's hull ; and to ascertain positively whether it is
owing to the ship's immersion, or to her form of bottom, it
would be necessary to lighten her, trim her to the same
draught as the Warrior, set her propeller exactly to the
same pitch, and try her again at the mile under, as nearly
as could be done, the same circumstances as attended the
Warrior's trial. With reference to the speed of ships
under steam generally, some misunderstanding appears to
exist in the public mild, If a ship is stated to have made
14 knots at the measured mile many persons look upon this
as denoting the ship's future speed at sea. Never was a
notion more fallacious. From all speeds made at the
measured mile 11 knot may be deducted, the remainder
giving the ship's best rate of speed at sea, with good"fuel,
clean fires, and the ship, in fact, " pushed" to do her best.
Taking a ship's average speed at sea, two knots may be
deducted from the measured mile rate. The reason of this
is obvious. At the measured mile she burns the best
picked fuel, her fires are attended by a body of experienced
stokers from the steam factory of the dockyard, under their
own foremen, and the trial is never made when important,
like the Black Prince, except under the most favourable
circumstances of weather. This explanation will account
for the apparent discrepancy in the speed of the Warrior on
her late run with the Lords of the Admiralty in their yacht
Osborne down Channel and what she realized at the
measured mile. When the Warrior made her 14.354 knots
at the measured mile her average speed was set down at
121 knots, and this, with a clean bottom, there is no doubt
is her true sea rate. Meanwhile, it is worth observing
, here that notwithstanding the numerous "infallible" pr e-
-1 parations for preserving clean the bottoms of iron ships
there is yet a noble fortune to be won in that way.
The Black Prince will make her trial of speed at half-

boiler power to-day, after which she will be swung at
Spithead to ascertain the deviation of her compass, pre•
paratory to proceeding on her maiden cruise. Whether she
or the Warrior eventually possesses the superiority in On;
of speed, the Black Prince is emphatically a grand ahiPl and
Captain Wainwright must feel just pride in being Pl6ced
in command of her.

Saturday
.0:: Tglireeatfihrospt
WORCESTER 110 P MARKET,
our market toisiidal
in
i et
beingoi] l b e ri,m but,from
instead of
ebnut t,
sample of 1862 hops was shown
and all the warehouses
not of Worcester growth, the samspe
lictla.se, there will probably
and purchased by a Worcester merclan
this
fair takes place on the 19th of
b2e,Oinogo or x,OOO peoecikeeetesnabeeintiesbr
rare everit), are
not be 50 pockets on sale.
,with prospect in view old
isereasuag in value. Last year's growth,
hops are gradual,'
eagerly bought up at
when offered (now a
ato £ IQP' P Per "it'