The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1850-10-29 00:00:00

RAILWAY AFFAIRS.

The Electric Telegraph Company are about to extend
the wires to Chester, and thence to Birkenhead and Holy-
head.

The Lord Mayor of London gives a banquet on the
6th November to the chairmen and directors of the prin-
cipal railway companies.
Messrs. Fox and Henderson, the contractors for the
completing of the Cork and Bandon Railway, have been
declared contractors for making the wire rope of the elec-
tric telegraph to be laid down between England and
France.

THE BRITANNIA BRIDGE.—The permanent public
opening of the new line of tubes for the down line from
London to Dublin took place on Monday, the great struc-
ture being now in all important respects made complete.
The first experiment consisted in passing two locomotive
engines through the tube, and resting them at intervals
in the centre of the sections. A train of 28 waggons, and
two locomotives, with 280 tons of coal, was drawn into all
four of the tubes, the deflections being carefully noted.
These deflections were ascertained to be exactly three-
fourths of an inch under this load. After repetitions of
these experimental ordeals, which occupied several hours,
the train of 280 tons, with two locomotives, was taken
out about a mile distant from the tube, and then suddenly
shot through it with the grea,est attainable rapidity, and
the result was that the deflection at this immense velocity
of load, was sensibly less in the way of undulation than
when the load was allowed to remain at rest on the tube.
The contrivance, by which the effects are indicated with
great precision, consists in a large pipe containing water,
laid along the lower cells of the tube, one end rising up
within the tube at the centre, and the other end fixed
against the stonework of the abutments of the bridge.
Both extremities of the pipe are furnished with glass
tubes and graduated scales, by which the relative levels
of the water were easily ascertained. As the slightest
leakage or evaporation over the ordinary thermometric
expansion of the water would derange the level, while
only half the actual deflection of the tube was registered
at each end of the pipe, these disadvantages are obviated
by the addition of a large reservoir of water in the inte-
rior of the tube, which is covered with oil and placed
beside the graduated scale. This larger area exhibited
the whole of the deflections at the abutment extremity,
and the apparatus presents a perfect representation of all
the deflections and phases of the great structure. The
heaviest gales through the Straits do not produce so much
motion over the extent of either tube as the pressure
against the side of the tubes of ten men ; and that the
pressure of ten men keeping time with the vibrations
produces an oscillation of 11 inch, the tube itself making
67 double vibrations per minute. The strongest gusts of
wind that have swept up the channel during the late
stormy weather do not cause a vibration of more than a
quarter of an inch. The broadside of a storm causes an
oscillation of less than an inch ; but when the two tubes
are braced together by frames, which is now being done,
these motions it is expected will cease. The action of the
sun at midday does not move them more than a quarter
or three-eighths of an inch. The daily expansion and
contraction of the tubes varies from half an inch to three
inches, attaining either the maximum or minimum at
about three o'clock a.m. and p.m. If a compass be held
over any part of the bottom of the cells, the south pole is
affected, and if held over the top of the cells, the north
pole is affected ; and this effect is observable in all parts
of the tube, whether at the centre or the end, although
their position is only about ten degrees west of the mag-
netic meridian. Preparations are making for covering
the tubes with a light arched roof of peculiar construc-
tion.