The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1861-08-22
A Novel Experiment..

from ths London Mechanics Magazine
On Wednesday some experiments on n
rather large scale were made on the rieh
bGak of the Thames and Immediately below
the raiiway bridge, EattsrseG, with Il view to
testing The efficiency of transmitting goods
and parcels proposed by the Pneumatic Dis
pitch company The mechanical arrange
ments III cCnnexion with the experimental
lire OF cast-irOn tubir (Which, like q huge
black snake, stretches Tor more than a quarter
Of Ii mi3 along the river side-are few and
simple. Under temporary shed high pres.
sure steam engine OF thirty horse power
made by Watt Il 90, and having It's cylinder
placed at an angle OF iorty-five degrees, is
erected, and il gives direct motion through
the me- edInm OF crank TO & large disc Of shseG
iron.
The disc runs on tubular bearings. and nar-
rows from about two teetsix inches in breadth
al lts centre TO three inches at its cirCunfer-
ence, its diameter being eighteen feet. It's
inserior contains simply tour arms, TO which
the sheets or iron are fastened, and which
serve rs fans or exhauster Through the
hoJOW bearing upon which the disc Is made
to rotate AT Il speed of from one hundred and
1ifty to two hundred revolutions per minute,
q communication exists with O. vacuum cham
ber below, and by the laws of centrifugal ac-
tion The latter is speedily exhausted, to n GER
tain extent OF air. The speed, In fact, CT the
disc determines that extent, ard water ba-
rome'er registers il The air rushes out with
considerable IOrce from the periphery of the
disc. Between the vacuum chamber and the
pneumatic tube, which is two feet nine inch
eS high, by feet inches in bread In and
transverse section OF which resem bles that OF
the Thames Tunnel, there are fitted valves
with hand levers for opening and shutting
them. These may be said 20 comprise the
whole OF the motive and propelling agencies
OF The pneumatic system.
The tube has been laid down in Battarsea
E:eIdS, IN Sucn Inanner as TO test severely
The practicaoiity of the scheme II has sew
erai very sharp curves and steep gradien Is
throughout its length, and is socket ioiGted,
SO rs 10 t1aFe lis Interior. which IL
came from the sand, tree from obstruc ton.
Inc carriages are live feet in length, OF sheet
iron, and each runs upon four cast-iron
WheelS OF eighteen inches III diameter. The
raits-so to speak-are cast in the bottoms OF
The Iuoes, and REQ Uire, therefore, no ''iaying"
Dut tnat Wnicn the setting OF the tubes them
selves gives them. A few strips OF vulcan
iZed lndia-rGsber screwed rou nd the circam- =
terence OF the fore end CT the carriage consti-
tute the piston. This, however, by 10 means
closely its the tube In fact, there is fully
three-elshths Oh an inch clear between the
exterior OF the piston and the interior Of the
tube.
There is no friction, therefore; and, sirgu-
lar TO say, the leakage OF air does not interfere
with the speed OF transit. This can only be
accounted for by the large end area which the
Carriages nave, In comparison with tn6 snail
area OF leakage space and the comparatively
low vacuum required. On Wednesday, last
the nrst experiment made was by loading 3
carriage win ore ton of cement ia bags, and
entering 1t into the open end OF the tube. Up
on given signal the engineer TO the company
caused tue starting valve TO be opened, the
water barometer showing column OF seven
inches IN height, and the disc running at the
rate,of 100 revolutions per miuule.
10 hfty seconds after, the carriage with its
contents found its way into the engine house,
through door at the end of the tube, which
1t forced open, and then ran Onward on rails
to butt placed to stop its progress. Next
two tons weight were placed in one OF the
carriages, and Its transit occupied eighty sec
Ouds under SIM liar m q Ybn
um was now lowered until tine barometer
guage showed two inches of water only, and
& living passenger, in the shape of a not very
handsome dog, was placed with one ton weight
Of dead 81 tocA. in carriage. The signal was
made by the Workmen at the open end OF the
tube, the communicating valve was opened,
and in one minute and half the carriage and
Its four legged guard were In the engine house,
the latter apparently not at all the worse for
the exhausttng process 70 which he had been
subjected.