The Republican. [volume] (Oakland, Md.) 1877-current, 1881-10-15
Electrical Curiosities at the Paris Ex.
hibitiOn.


Ever since M. Gramme introdpoed
his beautiful machine for generating
the electric current, his principle has
been adopted in a host Of other inyen-
lions. Shortly afterward a new value of
the machine was found. l we'll remem-
Der. in 1875, returning from prolonged
absence from England, had occasion
to write to the late Professor Clerk
Maxwell, and incidentally asked him
what was the greatest discovery Of late
years. He replied that. in his opinion,
the greatest discovery was shat
Gramme machine could be reversed''-
i. E., that when q current was passed
through the machine it might be used
to drive machinery. The belief of the
Professor was shared by many others.
and hundreds of people have been since
then engaged in applying this new
means of transmitting power to divers
purposes. The Electrical Exhibition
contains large number of these, many
of which can even now be seen in ac-
ton, but complete notion of these ap-
plications cannot be gained until the
steam-engines, the source of nearly all
the electricity to be used in the exhibit
ton, are in more advanced state. l
will, however attempt very shortly to
give some idea of the most interesting
examples in this department.
A great deal of popular curiosity
will, doubtless, be excited By two thor
oughly French toys on large scsle,
both made by M. Trouve. The fist is
the electrical boat, which is a full-sized
boat for three people, having attached
to the near end of the rudder a screw
driven by small electro motor. The
screw passes through void space in
the rudder. The motor is fed by three
large bichromate cells. Tie mode of
attachment of the screw causes it to as
sist the rudder in turningthe boat, so
that M. Trouye has been easily able to
float round the artihcia pond which
surrounds the Lighthouse in the center
of the building, and to pass under the
picturesque arches BY which it is
SPAWNED at the rate of about mile an
hour.
The other is the electrically propelled
balloon of M. TiSandier. 1t is an
elongated balloon, three metres long
and one and a third in diameter. 1t is
filled with hydrogen, and has screw at
the rear, driven by an electro-motor,
designed by M. Trouve. 1t can also
carry couple of The secondary cells of
M. Plante. A wire is suspended across
the building from one gallery to the
other. and the balloon rises above this
wire and travels along it when the cur
rent passes. A fin placed in front pre-
vents it from swaying. But the motion
is very slow, and at present the machine
is little more than an electrical toy.
Still more interest will, however, be
excited by the tramway car driven by
electricity, the invention of Messrs.
Siemens. In this tram car, which runs
from wooden station on the Place dc
La Concorde into the exhibition, the
current is generated by powerful
dynamo machine within the building.
1t is then carried by wire mounted on
strong posts, from which it is tapped
by carriers on the car, whence it de-
scends to beneath the centre of the car.
Here the current, passing through a
dynamo machine, sets it in rotation, and
by a chain connection this machine is
geared to the axles of the wheels. The
velocity of rotation is reduced to one
third by this gearing. The chain con-
nectiOns are all on one side in the case
of both aXles. There is also an arrange
ment supplied for taking the current
directly from the rails, but it must be
very rarely that such means could be
utilized on an ordinary tramway, and at
present it is discarded. The appear
ance of the car is very handsome, and
shows few external signs of the power
which may be generated within it. Such
a car might be fitted with the secondary
batteries of M. Faure, which might be
| placed under the seats. The car would
be then self contained, and there would
be no necessity for having either the
aerial wire or the conduction through
the rails. Such self-contained car was
actually constructed and tried in Paris
some months ago, but serious difficult
ties were then encountered, which,
however, | have reason to believe will
soon be overcome, and then we shall
have an opportunity of seeing car
running on tramway and carrying its
own electrical store of energy.
In the electric brake of M. Achard,
applied to railway carriages, there are
upon the axle of each pair of wheels
two rings OF iron, about eight inches in
diameter and two inches wide. Besides
this there is second and independent
axle with two rings, one foot in diane
ter, facing the rings on the wheel axle.
These rings, however, are the two ex-
tremities of powerful electromagnetic,
which can be excited by coil of wire,
the ends of which can be con-
nected with the current gener.
ated in the locomotive by means
OF two pairs of strong copper
strings. So long as there is no current
passing the independent axle maintains
a fixed position, and the brake is kept
away from the wheels by strong spiral
springs. So soon, however, as the
current is allowed to pass the rings al
the two ends of the independent axle
are converted into magnetic poles,
which attract the revolving rings on the
axle of the wheel, from which thew are
separated by only one-eighth of an inch
The so-called residual force of the rings
produce a rotary force on the poles Of
the electromagnetic. The Independent
axis revolves and winds up a chair
IL IL.