The Sun.
London, England, 1866-09-03 00:00:00

A Wonderful Invention.

It is a curious fact that for the last four years an
invention, which may prove one of the most useful,
as well as the most wonderful of this wonder-
working age, has been on view within an hour's
drive of Paris, and that it should not have attracted
attention out of the scientific world, the general pub-
lic being unaware of its existence. It would lean
as though scientific discoveries were doomed for a
certain time to lead a chrysalis kind of life, during
which they are exposed to all manner of attacks from
members of the scientific body ; the result, too, often
being that the inventor has long been gathered ad
patres when the public begin to appreciate the re-
sults of his labours, and some enterprising, but com-
paratively ignorant practical man turns them to ac-
count.

These remarks are only partly true, as regards the
extraordinary invention we are about to describe,
but though it received the powerful support of the
Emperor, and gave rise to many a scientific con-
troversy, the general public are at this moment
unaware that at La Jouchere, close to the pretty
village of Bouginal, they have an opportunity of
witnessing every Sunday the extraordinary sight of
a railway train ascending a steep gradient without
the aid of steam, and the carriages of which are
destitute of wheels.

This invention is due to a French engineer, M. L.
D. Girard. It is founded on a new application of
an old principle—viz., that a layer of water intro-
duced between two metal surfaces enables them to
glide on each other with as little friction as a slab
of ice on the polished surface of a frozen lake. M.
Girard has conceived the idea of applying this prin-
ciple to locomotion, and the experiments he has been
carrying on for the last four years successfully de-
monstrate that it is applicable to the propelling of
railway trains. In his system wheels are dispensed
with ; and there can be no doubt that, were his in-
vention applied to ordinary railways, an engine
which now is only able to draw a train weighing,
say 500 tons, at the rate of 20 miles an hour, would
with the same expenditure of fuel be able to draw
double the weight at double the speed. M. Girard,
however, proposes to discard steam as a motive
power ; this is the weak part of his invention—the
value of which consists in the substitution of sledge
carriages, instead of carriages on wheels. These
carriages are fitted on slides, which fit upon rails of
a peculiar construction ; by simply turning a cock,
a stream of water is introduced between the slide
and the rail, and a gentle motive power being ap-
plied, the carriage, mounted on the slide, shoots
forward with a speed which has really no limit beyond
the considerations of safety.

To illustrate his system M. Girard has constructed
a model railway at the village of La Jouchere, near
Bouginal, between Paris and St. Germain. It is
not very easy to give an idea of it to an unscien-
tific reader without the aid of diagrams, but .it is
worth while making the attempt. The rails em-
ployed by M. Girard are broader and higher than
those in use on ordinary railways. Their upper
surface is 20 centimetres in breadth. I have
already mentioned that wheels are suppressed,
and that they are replaced by slides, or, to be
more accurate, by skates, differing only in shape and
size from those used by skaters. Thus each carriage,
instead of having four wheels, has four skates. The
skates have a kind of a ledge on either side, so as to
fit on to the rail, but not too closely. The upper
part of the skate, which is next the surface of the
rail, is hollowed at its centre by a small groove ; the
groove is pierced with holes communicating with
tubes, leading to a reservoir in the carriage, in which
a mass of water is subject by means of compressed
air to a pressure of from seven to eight atmospheres.
The turning of a cock establishes the communication
between the reservoir and these skates ; the water
then rushes as from a hydraulic p?ess through the
holes in the grooves of the skates, and a layer of
water is interposed between them and the rails, on
which they are thus enabled to move as on the
smoothest ice. The friction being thus reduced to a
minimum, the tractive or propelling force can be
greatly reduced. Horses might be employed were
the system applied to• the railway omnibuses such
as travel between Paris, Versailles, and St. Cloud,
and on ordinary railways with locomotive engines
there would be a great saving of both steam and
fuel. But, as before intimated, M. Girard discards
steam. He adapts the Pindaric system, ,g
pity ciptaTov," and trusts to water power. Here is
his modus operandi.
Between the rails he has constructed a longi-
tudinal tube, receiving water at a very high
pressure from a reservoir, established at a very
high level ; the tube is provided at every 50 yards
with a kind of stop-cock, which enables a powerful
jet of water to be directed horizontally in the direc-
tion the train moves in. The first carriage is pro-
vided with a sort of needle which opens the stop-
cocks, the water rushes forth against small paddles,
placed under each carriage, and communicates to
the train such an impetus as to enable it to ascend
very steep gradients without any diminution of
speed. By an ingenious contrivance a portion of
this water is conveyed by the turn of the paddles
into the reservoir of the motive-carriage, and is
utilised to neutralise the friction between the skates
and the rails.

To descend gradients the motive power is unne-
cessary. The train descends by its own weight, and
its degree of speed can be regulated by diminishing
or increasing the supply of water under the skates..