The Sun.
London, England, 1849-09-10 00:00:00

Interest

... ... £10,050

Repair of road ... ... ~. ... 180
Year of engine ... 6,6; 250
Fuel ... ... ... ... ... 100
Two enginemen... ... 660 ... ... 150

£40,730
A thcusand pacsengcrs per day, at 31 each for
twelve miles, would be ample to realize 10 per cent.
upon the turnpike road, whereas it would have re-
quired something like 2s. 6d. to 3s. each to have
realized 5 per cent. on the railway, thus proving that
even gold may be bought too dearly, which I hope
very soon to be enabled practically to demonstrate.
By adopting a good timber track, which may be
fixed on the middle or side of the road, without the
least inconvenience to the public (but, on the con-
trary, be a great accommodation to the public using
it, and thereby enjoying the easy motion consequent
thereon), the perfect success of steam on common
roads so provided appears to me to be indisputable,
and that a large profit may be realised, at the charge
of one halfpenny and one penny per miIe.—THOMAS
MOTLEY, C.E., Stangate, Lambeth, 8 nio. 29.

NOVEL INVENTION FOR BOILERS

OF STEAM-ENGINES.
An experiment to test the powers of Wright's
Patent Steam-Generator,l in its application to the
boilers of . steam engines, was made on Saturday, at
the premises of the inventor, in Great Suffolk-street,
Borough, and the result was entireiy satisfactory. For
years the great object of scientific men has been to
endeavour by mechanical or other contrivances to
generate the greatest amount of steam by means of
a given quantity of fuel, and thus to diminish the cost
of producing it, and to render it unnecessary for steam-
vessels to have a large space set apart for the stowage
of coals ; but, singularly enough, all efforts in this
direction have been attended with little success, al-
though during the last few years many considerable im-
provements have been effected in all that concerns the
working of steam- engines. The invention of Mr. Wright
consists of a simple, but, nevertheless, of a very in-
genious and beautiful arrangement, which appears to
be entirely novel in its conception, and to be superior
to any other that has originated in a desire to arrive
at the same result. The principle consists in having
two sets of tubes, or " cellular vessels," which are
made of malleable cast-iron, and are hollow through-
out; one of which is placed between the fire and the
boiler, and the other inside the boiler. These cellular
vessels, which resemble a kind of iron net-work,
having in them small holes or interstices, com-
municate with each other by means of bent
tubes, and they are charged with compressed
water, which, as it cannot evaporate into
steam, does not require to be changed.
As the flames from the fire can only touch the boiler,
through the interstices, the water contained in the
cellular vessels absorbs a great portion of heat, and,
by becoming inferior in gravity, rises through the
bent tube, and diffuses itself through the correspond-
ing vessels abave. Having given off its excess of heat
to the water inside the boiler, it decends by increased
gravity through the bent tubes to get a fresh supply
of heat, and thus a continuous current of water is
kept up in the cellular vessels and the tubes in fact,