The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1861-01-23
SLAVE STATES.
- e6S, S,94s
So. miles. 1,795 ,965
Population 10, 100000.


NEW DISCOVERY IN STEAM NAVIGATION IN ENGLAND
"A 1rlat on the Thames.-On the 11th ult, trip
was made down the Thames to test the merits of
an invention, which is opposed to all the received
notions with regard to the propulsion of vessels
whether by the oar, the paddle-wheel 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 re-
sisting surface is presented, namely the rim of
thin disc, revolving on the axis, like the ordinary
paddle-wheel. This "disc wheel'' is the invention
of Mr.. James Jones Aston, barrister who has for
some years devoted his attention to steam navira-
tom 1t consists Of solid circular disc of metal
or wood, or both in combination, with plain edges
made as thin as possible consistently with its be-
ing strong enough to be turned in the water with
out breaking ''buckling."
one at the stern or one each side will propel
boat, put several may be used On the shaft at
equal distances apart. The portion not acting in
the water can be cut away and the disc filled with
arms or spokes. Its advantages over the paddle-
wheel and the screw consist in the motive power
being so perfectly utilized as to obtain greater
rate of speed than has hitherto been practicable,
In ITS being less likely to be disabled in storm or
battle, and in the entire absence of paddles or
blades to agitate the water and to give vibration
to the boat. Mr.. Aston obtained the use of an old
heavy and numbering craft and substituted his disc
wheels for paddle ones, which were before en-
pioyed. Each wheel was composed of several
metal dlscs open in the centre. about fourteen feet
IN diameter, and little more than two feet in the
""tS'. hc ooaI tHus prepared, ana with Its OrQl-
nary engines working the wheels moved off slowly
increasing its speed until it went little more than
six knots an hour.
There were forty-seven revolutions in minute,
and the consumption of coal at the rate of twelve
and half hundred an hour, with pressure of six
pounds on the boiler the usual speed of the vessel
with the padde-wheels, being eight knots with one
ton of coal. As the wheel meets with so little re-
sistance from the water, it ought to be- in Mr. As
tons opinion, propelled at a velocity superior to
existing marine engines. To the scientific it would
De matter OF nice investigation how these wheel;
act upon the water as to move along a vessel o
| such bulk. The defects in the invention NAV he
said to be difficulty in making quick start and
In suddenly stopping, but these NAV be overcome
! py the skill OF a clever, practical engineer Mr.
Aston alleges various grounds for the superiority
| OF his disc wheel; no loss of power from back
water, its liability to be much less effected by winf
and tide. Its suitableness for canals ard shallow
rivers, and its cheapness. 1t be easily applied
to all paddlewheels and also to the stern; but ir
the case OF screw, some alteration to the ma
chinery would be necessary.
RAILROAD ACKNOWLEDGEMENTS of tn,
five great trunk lines of railroad arrived in thi:
city yesterday for the purpose of consulting in re
iation to the effect of the present difficulties upor
their interests. The Presidents, agents. &C. of tn,
In9iiowing roads are present: Baltimore and Ohio
new iork and Erie, PENNSYLVANIA Central New
1ork Centrai wabash and Western, Pitts burg
Ooinmola ana Cincinnati, Wilmington and Balti
more, ana Catawlssa roads. Their first business
meeting was held last evening" Washington Star
Jan. %.
In single town of Maine, containing onlv fou
hundred and fifty inhabitants, thirty-two peopl
aled lat year OF consumption.