The Sun.
London, England, 1855-04-06 00:00:00

INSTITUTION OF CIVIL ENGIN2ER2

At the last meeting of this society, Mr. George P.
Bidder, vice-president, in the chair,
The discussion was renewed on Mr. R. A. Robinson's
paper, "On the application of the Screw Propeller to
the larger class of Sailing Vessels," and was continued
through the evening.
It was argued that a vessel carrying 3,000 tons, be-
sides machinery and coals, would require 1,000 H.P.
(indicated) to obtain 8i knots per hour, and even by
that means could not save more than 7A days in a
voyage like that of the Red Jacket. Arguing from
these premises, and demonstrating the position by a
diagram, showing the courses of various ships, it was
contended that the commercial advantages of employing
auxiliary steam-power, on voyages to Australia, were
questionable, inasmuch as the small saving of time on
the voyage could not command such an increase in the
rate of freight as had been named. The prevailing
westerly winds and currents in the Southern Ocean
might always be depended upon, if a proper course was
taken, as laid down in Lieutenant Maury's charts, and
it was not improbable that, from a continuance of the
same admirable observations, as had served for the
foundation of these charts, and the classification of the
valuable documents said to exist in the archives of the
Admiralty, such further information would be obtained
as would eventually still shorten and render more cer-
tain the voyage of the sailing clippers. It was admitted
that small auxiliary power would be very desirable for
enabling clipper-ships to work into and out of port, and
to make some way in what were called the "Horse
Latitudes;" but the expectation of great advantage
being derived on the Australian voyage was contended
to be fallacious. These remarks were not meant to
apply to auxiliary screw-clippers intended for other
routes, but rather to enforce the position of its being
always necessary to consider carefully the peculiarities
of the intended station, and to adapt the power and
means of propulsion to them. The question of the
speed of American vessels was again raised, and it was
contended that the transcripts of the logs al:tiled
to were correct, and did fairly represent the speed at-
tained. It was shown that the Great Britain, having
14,000 yards of canvas in a suit of sails, exceeded in ex-
tent of sails any of the clipper ships, and that although
it had been predicted for her that she would be a very
fast steamer, yet it was not supposed that she would
attain the great speed under canvas which she had ac-
tually exhibited ; it having been stated that she had run
17 knots per hour, whilst dragging her screw through
the water. The peculiarities of the method of building
American vessels were described, and instances given
of the facility of repair of well-built vessels, as compared
to some of the cheap rapidly-built ships that had been
turned oue for the California trade. Reference was
made to the forms introduced to the institution by
Captain Henderson, in 1847, and again in 1853, with
the object of obtaining the particulars of area of mid-
ship section, lines of displacement, power of engines,
&c., which were now asked for from the author of
the paper, who had furnished all that could be
obtained ; it was suggested to members to supply
these, in order to render the paper complete for reference.
It appeared to be shown that neither the full-powered
steamers nor the large auxiliary power sailing ships,
hitherto placed on the Australian route, had been com-
mercially successful, and therefore a class of minimum
power auxiliary screw propelled ships, fully rigged, was
advocated, with a view of sailing at all times, should the
wind serve, and only to employ their steam power in
calms and under favourable circumstances. When the
sun was far north, the trade wind ceased and calms
commenced, in 153 deg. to 16 deg. north latitude,
and continued as far as 3 deg. to 4 deg. north, cr
over a space of nearly 700 miles, in the usual track
of ships from the North to the South Atlantic. In
the contrary season, with the sun far south, the trade
wind usually failed in about 6 deg. north latitude,
and thence to the equator, or 2 deg. south, constant
calms prevailed over 400 to 500 miles ; the ships only
getting over that space by occasional squalls of short
duration. Now it was in these positions that the mini-
mum power was required, and by its judicious use it
was very possible to save ten days on the Australian voy-
age, and make a corresponding profit. As to the com-
pensation of the lifting the screw of the Dauntless in a
frame by 30 men in nine minutes, as compared with
turtling up that of the Caroline upon a rule-joint in the
dead wood with three men in three minutes, there could
not be any question as to which was the best system for
a trading vessel ; and it was contended that the screw
should rem=ain always coupled to the driving shaft, to
avoid the rattling and noise arising from having easy
allowance for coupling. As to American vessels coming
to Great Britain, it was contended that it was beneficial
for both shipbuilders and merchants that the Ame-
rican vessels should beat those of this country, as
otherwise the desire of having immense cargoes car-
ried in vessels of nominal small tonnage would do
away with all scientific improvements in construction.
The Americans had, moreover, shown that something
of cargo must be sacrificed to speed, and this country was
much indebted to them for the lesson ' • as also for denim -
strating the necessity for having the best practical sea-
man for the captain, and making it his interest to get as
much out of the craft as her power and speed would
give. It was contended, that as far as it had been prac-
ticable to procure such information, the displacement
and the immersed area of ships had been given in the
paper, but there was great difficulty in obtaining such
data correctly from the builders. The consumption of
coal fur the distance run was also stated, as far as was
practicable ; because this was recognised as the only true
means of ascertaining the commercial value of the auxili-
ary power. Nominal horse power has been referred to
more as a standard of the first cost than as affording any
measure of the power really employed. The general
assumption was, that having engines of two hundred
horse power (nominal), and with the expenditure of
350 tons of coals, a sailing clipper ship, with an
auxiliary screw propeller, might save ten days on
an average passage to China or to Australia, supposing
the steam only to be used in calms, -and under circum-
stances to enable a maximum effect to be produced by a
minimum expenditure of fuel ; it being taken as proved
that a minimum powered clipper ship could not pos-
sibly-be commercially successful if overloaded with coals,
or consuming such a quantity of fuel as had been re-
quired by the auxiliary power ships hitherto in use. Full
credit wasgiven to the charts of Lieutenant Maury for
pointing out the steady wind course, but it was con-
tended that even on that track, at certain periods, there
were winds so light that the best ships could not make
more than two knots an hour. It was maintained
that the author of the paper bad not received any
intimation of the construction of the Royal Charter,
and that the fact of the adoption, by so emi-
nent a firm as Messrs. Gibbs, Bright, and Cq. of the
dimensions of the ship, and the power of the engines,
so exactly similar to those advocated by the author,
was the best proof of the soundness of his views. It was
contended that this commercial question was of greater
importance, but it would have been desirable that it
should have been preceded by a paper on the forms and
capabilities of screw propellers ; it was, however, sug-
gested that such a communication should still be made,
when the whole question would be re-opened, and the
experience of the relative merits of the various systems
of lifting the screws, and the results of dragging them
through the water, could be fairly laid before the meeting.
Doubts were expresse I as to the anticipated advantages
of having a very small engine merely to give a slow
speed to the screw when the vessel was under sail, and
calculations were given to demonstrate its inutility, based
on the results obtained by Messrs. Maudslay and Field in
their experiments on the feathering screw. The benefits
arising from the friendly rivalry between America and
Great Britain in ship-building, in engineering, and in
general manufacturing and production, were frankly ad-
mitted, and fervent hopes were expressed for that being
the only kind of rivalry the two countries would ever be
engaged in ; it was the only contest in which the least
successful was the greatest gainer.

After the meeting there was exhibited in the library a
model of a system introduced by Mr. Clifford, for lo wering
ships' boats from the davits evenly, quietly, and safely, in a
gale of wind, and disengaging them without any risk of
capsizing,or being dragged under by the speed of the vessel.
The chief point was the employment of a block of a novel
fut m,having three sheaves placed over each other,through
and between which the lowering ropes passed in such a
manner as to have a tight grip upon them, and yet so
that, by letting all run free, the falls would run out in
such a manner as to let the boat down on the water on
an even keel, and quite free from the" ship. The lower-
ing could be accomplished by a man sitting in the boat,
and, though with a full loading, the descent could be
checked at any point. It was evident that by this
system the disastrous effects of undue haste in rushing
to the boat', in cases of danger, would be completely.
obviated. S. simple in4enious system of a hollow ro-
tating boat-plug for the bottam of the boat was also
shown.

It was resolved, that in order to insure a fuller attend-
ance ofmembErs than could be obtained on Easter Tues-
day the meeting should be adjourned by special reso-
lution until Tuesday evening, April 17th, at eight p.m.,
when it was announced that Mr. Burleigh's paper " On
the Construction of Railway Crossings and Switches''
would be read.

THE PENNY STAMP.—In Canada and Australia, where
society and institutions approach next in similarity to
our own, there is no stamp, and yet in both countries the
press does not, by any means, yield in respectability to
that of the mother country. On the contrary, we believe
we would look in vain amongst the journals of either
colony for anything so disreputable as we have some-
times seen in many Irish journals of microscopic circula-
tion, whose proprietors are now crying out against the
invasion of their vested rights, and the dangerous im-
morality of an unstamped press. The law as it is does
not and cannot prevent the publication of unstamped
news. The only effect of it is to drive the unstamped
trade into the hands of persons of bad character, who
will, therefore, give to their customers a bad and low
article. And surely no law can be beneficial which allows
a man to purchase, perhaps, treason, blasphemy, and
pruriency, at one shop for a penny, and compels him to
religion, and
clhaTtcitaetr elassesntexttwdicoeort.h—eLperiinc:terkEr xil)oryeassl.ty,

SINGULAR CONVERSION OF A CHURCH.—Archbishop
Tenison's beautiful chapel in Regent-street, has under-
gone a singular change during the last few weeks.
Those who know the neighbourhood will remember that
the building was approached by a very large vestibule of
corns architectural pretensions, but the rector of St.
James's (in whose parish Archbishop Tenison's chapel
is situate) determined that it should be turned to some
account, and jit has now undergone a thorough meta-
morphosis, and been converted into shops. No acci-
dental passer-by would ever dream that the chapel
founded by the pious archbishop had been driven into a
back street, but still it is the fact, and more than that,
the plan has met with the approval of the highest eccle-
siastical authority in the diocese.