The Sun.
London, England, 1860-12-12 00:00:00

NEW DISCOVERY IN STEAM IVAVI-
GATIO.N.

Yesterday a trip was made down the Thames to
test the merits of a novel but extremely simple
invention, which, if it succeeds, may create almost
a revolution in steam navigation. The discovery
is the more remarkable from being opposed to all
the received notions with regard to the propulsion
of vessels, whether by the oar, the paddlewheel, or
the screw. In those cases the motion is obtained
by the broad surface which is brought to bear upon
the water, whereas here the least conceivable
resisting surface is presented, namely, the rim of a
thin disc, revolving on an axis, like the ordinary
paddle-wheel. To use a familiar illustration, the
principle adopted would seem to be nearly analo-
gous to that of moving a floating body by means of
a knife turned rapidly round, the sharp edge instead
of the side being kept next to the water. At first
sight that would appear to be an ingenious contri-
vance to get the very lowest rate of speed from a
given amount of power, but the result of the experi-
ment yesterday was calculated to considerably
modify such an impression This " disc wheel," as it
is called, is the invention of Mr. James Jones Aston,
a barrister, we believe, of the northern circuit, who
has for some years devoted his attention to steam
navigation. It consists of a solid circular disc of
metal or wood, or both in combination, with plain
edges, made as thin as possible, consistently with
its being strong enough to be turned rapidly in,
the water without breaking or " buckling."
One of these at the stern, or one at each side, vall
propel a boat, but several may be used on the same
shaft at equal distances apart. The portion not
acting in the water can be cut away, and the disc
filled with arms or spokes. The chief of its advair
tages over the paddle-wheel and the screw, 10
enumerated by the patentee, consist in the motive
power being so perfectly utilised as to obtain a
greater rate of speed than has hitherto been deemed
practicable, in its being less likely to be disabled
in a storm or battle, and in the entire absence of
paddles or blades to agitate the water, and to give
vibration to the boat. It was not expected, nor
attempted, to demonstrate satisfactorily the first of
those advantages by yesterday's experiment, as it
was made under very unfavourable circumstances;
but that ships, and heavy ones, too, can be sent
along quickly by this new mode of propulsion was
placed beyond doubt. Mr. Aston had obtained the
use of a tug called Saucy Jack, an old, large, heavy',
and lumbering craft, whose characteristics certainly
did not answer to her name, and substituted his
disc wheels for the paddle ones which were before
employed. Each wheel was composed of four metal
discs, open in the centre, about 14 feet in diameter,
and a little more than two feet in the water. It is
but right to mention that the wheels were only put
together in a rough and temporary manner; and
that, in order to meet the inventor's plan, they
ought to have sunk at least another foot in the
stream, which would have given greater speed. The
boat thus prepared, and with its ordinary engines
(which were an old-fashioned description) working
the wheels, started from Blackwell in the morning
with a small party of gentlemen, including 11r.
Aston, Mr. Wright, of the Admiralty ; Captain
Lovell, of the Peninsular and Oriental Compaq;
Mr. Macrory, barrister; Mr. Adam, of the House
of Lords ; and a few others interested in the e -
sycrraC:o.
nunot
down
oTutaeowi
There
maximum
ra,
at
consumption
went
oh:
wnmeietbeingenuhrtme ofriver,aao4cgiven,bo7pl
periment. It was shortly after high water, and,
omssmr tidepianxoi
tenvee
kutediohndtnfeeob,ioltytwsaff2idao
dnrfescadgl
wthovrhwootee,
.uue
tiartaliertinslsenecsvewruomderiaaeuowss rtioiaienotftghti
36htstihiabbt:oses.
the tug
on the boiler, the usual speed of the vessel, with
the paddle-wheels, being eight knots with one to.n
of coals; but it would be unfair to draw any rigl9;
comparison between the two performances until
the disc wheel is worked by machinery properlii -
adapted to it. In the first place, as the
meets with so little resistance from the water, it
can and ought to be, in Mr. Aston's opinion, Pre,::
pelled at an immense velocity, to which noeexit"ist"
ing marine engines are probably equal, and which
would require a multiplication of machinery, Pfl,,
cogs, or some other mechanical contrivance. 11;
was also stated that with the same amount 01
power by which the six knots were got, the
1!11. tug
with its old wheels would scarcely move at
To the scientific it would be a matter of nice M:
vestigation and speculation how these wheels act,
upon the water so as to move along a vessel of suchbulk. The motion was extremely easy and stead9_,
and of course the swell from wheels of such coo.
struction was very slight. The defects of the inve n_
tion may be said to be a difficulty in making ,
quick start and in suddenly stopping,
but the "',
al
may be overcome by the skill of a clever practic
engineer. A good run was made at the speed we
have mentioned to Erith, and then the tug return.eo
c!
up the river against tide and a strong head r win
at the rate of five knots, with a diminished p.
es
sure of steam. Mr. Aston
of his dis
other grounds for the superiority
no ,
wheel than those already specified ; for insta
_e_
also alleges various
much less affected by wind and tide, andoliii:
no loss of power from back water, its liability to .t'.!
suitableness for canals and shallow rivers,
and at $
of being worked with much less power,
.
lied t°
any water where a boat can.
.float, and its capabilitY
-ls and also to the stern; but
all padule-vvhee _achitierl"
great saving of fuel. It can be easily aPP, a. in
the case of a screw some alteration of the ra
would be necessary. The invention, we reneaatnT:;
well deserving some further and more extended
well an unexpected and singular result, cl
and perfect trials.