[Illustration: Fig. 6.--Pedal for Sending Warning to Railway
Crossing--Plan View. Fig. 9.--Lartigue's Bellows Pedal--Longitundinal
Section Fig. 10.--General Plan.
Fig. 16.--Controller for Water Tanks (Vérité System). RAILWAY
APPARATUS AT THE PARIS ELECTRICAL EXHIBITION.]
_Lartigue's Switch Controller._--The object of this apparatus is to
warn the switch tender in case the switch does not entirely respond to
the movement of the maneuvering lever.
The apparatus, which is represented in the accompanying Figs. 1, 2, 3,
and 4, consists of the following parts:
(1.) A mercurial commutator, O, which is fixed on a lever, B,
connected with a piece, A, which is applied against the external
surface of the web of the main rails, opposite the extremity of the
switch plates;
(2.) A bar, C, which traverses the web of the rail and projects on the
opposite side, and which carries a nut, D, against which the switch
plate abuts;
(3.) An electrical alarm and a pile, located near the switch lever.
As long as one of the two plates of the switch is applied against the
rail, one of the two commutators is inclined and no current passes. A
space of one millimeter is sufficient to bring the commutator to a
horizontal position and to cause the electric alarm to ring
continuously. If the apparatus gets out of order, it is known at once;
for if the alarm does not work during the maneuver of the switch, the
tender will be warned that the electric communications are
interrupted, and that he must consequently at once make known the
position of his switch until the necessary repairs have been made.
_Pedals for Transmitting Signals to Crossings._--On railways having a
double track and doing a large amount of business it becomes very
necessary to announce to the flagmen at railway crossings the approach
of trains, so as to give them time to stop all crossing of the tracks.
On railway lines provided with electro-semaphores there may be used
for this purpose those small apparatus that have been styled semaphore
repeaters.
Mr. Lartigue has invented two automatic apparatus, by means of which
the train itself signals its approach.
1. The first of these, which is generally placed at about 6,000 feet
from the point to be covered, consists (Figs. 5, 6, 7, and 8) of a
very light pedal fixed to the inside of the rail, and acting upon a
mercurial commutator. A spring, R, carried upon the arm, a, of a
lever, A, projects slightly above the level of the rail, while the
other arm, b, carries a commutator.
The spring, R, on being depressed tilts the box containing the
mercury, closes the circuit, and causes an alarm, S, located at the
crossing, to immediately ring. In this alarm (Fig. 8) a piece, P, is
disconnected by the passage of the current into the electro-magnet, E,
which attracts the armature, a, and, a permanent current being set
up, the apparatus operates like an ordinary alarm, until the piece, P,
is placed by hand in its first position again.
2. The second apparatus, exhibited by the Railway Company of the
North, and also the invention of Mr. Lartigue, bears the name of the
"Bellows Pedal." It consists (Figs. 9 and 10) of a pedal, properly so
called, P, placed along the rail, one of its extremities forming a
lever and the other being provided with a counterpoise, C. When a
train passes over the pedal, the arm, B, fixed to its axle, on falling
closes the circuit of an ordinary electrical alarm, and at the same
time the bellows, S, becomes rapidly filled with air, and, after the
passage of the train, is emptied again very slowly under the action of
the counterpoise. The contact is thus kept up for some few minutes.
This apparatus works very satisfactorily, but is cumbersome and
relatively high-priced.
_The Brunot Controller as a Controller of the Passage of Trains._--The
Brunot Controller, which has been employed for several years on the
Railway of the North, is designed to control the regularity of the
running of trains, and to make automatically a contradictory
verification of the figures on the slips carried by the conductors. In
Fig. 11 we give a longitudinal section of the apparatus. It consists
of a wooden case containing a clockwork movement, H, upon the axle of
which is mounted a cardboard disk, C, divided into hours and minutes,
and regulated like a watch, that is to say, making one complete
revolution in twelve hours. The metallic pencil, c, which is capable
of displacing itself on the cardboard in a horizontal direction
opposite a groove on the other side of the disk, traces, when pressure
is brought to bear on it, a spiral curve. The transverse travel of
the pencil is effected in ninety-six hours. The displacement of the
pencil is brought about by means of a cam. Under the influence of the
jarring of the train in motion, a weight, P, suspended from a flexible
strip, l, strikes against the pencil, c, which traces a series of
points. During stoppages there is, of course, an interruption in the
tracing of the curve.
[Illustration: Fig. 11.--Brunot's Controller. RAILWAY APPARATUS AT THE
PARIS ELECTRICAL EXHIBITION.]
Up to this point no electricity is involved--the apparatus is simply a
controller of regularity. Mr. Brunot has conceived the idea of
utilizing his apparatus for controlling the passage of trains at
certain determined points on the line; for example, at the top of
heavy grades. For this purpose it has only been necessary to add to
the apparatus that we have just described an electro-magnet, E,
connected electrically with a fixed contact located on the line. When
the current passes, that is to say, at the moment the circuit is
closed by the passage of a train, the armature, A, is attracted, and
the pencil marks a point on the cardboard disk. This modification of
the apparatus has not as yet been practically applied.
_Electrical Corresponding Apparatus._--The object of these apparatus
is to quickly transmit to a distance a certain number of phrases that
have been prepared in advance. The Company of the North employs two
kinds of correspondence apparatus--the Guggemos and the annunciator
apparatus.
1. _The Guggemos Apparatus._--This apparatus serves at once as a
manipulator and receiver, and consists of an inner movement surmounted
by a dial, over the face of which moves an index hand. Around the
circumference of the dial there is arranged a series of circular
cases, C, containing the messages to be received, and similar
triangular cases, containing the messages to be forwarded, radiating
from the center of the dial. Between each of these there is a button,
b.
Fig. 13 represents the interior of an apparatus for twenty messages.
It consists of a key-board, M, an electro-magnet, B, a clock-work
movement, Q, an escapement, s, and an interrupter, F G.
When one of the buttons, b, is pressed, one of the levers of the
key-board arrangement touches the disk, M, which is insulated from the
other portions of the key-board, and the current then passes from the
terminal C to M, and there bifurcating, one portion of it goes to the
bobbins of the apparatus and thence to the earth, while the other goes
to actuate the correspondence apparatus. The index-hands of the two
apparatus thereupon begin their movement simultaneously, and only stop
when the pressure is removed from the button and the current is
consequently interrupted. H is a ratchet-wheel, which, like the
key-board, is insulated from the rest of the apparatus. The button, K,
located over each of the dials, serves to bring the index-needles back
to their position under the cross shown in Fig. 12. The key, X, serves
for winding up the clock-work movement.
_The Annunciator Apparatus._--This apparatus, which performs the same
role as the one just described, is simply an ingenious modification of
the annunciator used in hotels, etc.
It consists of a wooden case, containing as many buttons as there are
phrases to be exchanged. Over each button, b, there is a circular
aperture, behind which drops the disk containing the phrase. Between
the buttons and the apertures are rectangular plates, P, in which are
inscribed the answers given by pressing on the button of the receiving
tablet--a pressure which, at the same time, removes the corresponding
disk from the aperture. Two disks located at the upper part carry
these inscriptions: "Error, I repeat;" "Wait." The tablets on
exhibition have eight disks, and can thus be used for exchanging six
different phrases. In the interior, opposite each aperture, there is a
Hughes magnet, between the arms of which there oscillates a vertical
soft-iron rod, carrying a disk. The maneuver "is simple." By pressing
upon a button there is sent into the bobbins of the magnet
corresponding to this button a current which causes the disk to appear
before one of the apertures, while at the same time an alarm begins to
ring. The same maneuver performed by the agent at the receiving-post
has the effect of causing the disk to disappear. The two contact
springs in communication at each aperture with the alarm and the line
are connected by a strip of ebonite, M, against the center of which
presses the button.
_Electrical Controllers for Water-Tanks._--The object of these
apparatus is to warn the person in charge of a water-tank that the
latter is full, and that he must stop the engine-pump; or, that the
tank is empty, and that he must at once proceed to fill it. The
Company of the North has on exhibition two such apparatus--one of them
Lartigue's, and the other Vérité's.
1. _The Lartigue Controller_ (Fig. 15).--This apparatus consists of a
long lever, A, which carries at one of its extremities a funnel, E,
having a very narrow orifice and which is placed under the overflow
pipe of the tank. The lever is kept normally in a horizontal position
by a counterpoise; but, as soon as the overflow runs into the funnel,
the weight of the water tilts the lever, and the mercurial commutator,
F, closes the circuit of a pile, which actuates an alarm-bell located
near the pump and engine. The two stops, a and _a'_, limit the play
of the lever.
2. _The Vérité Controller_ (Fig. 16).--This apparatus consists of a
float, F, provided with a catch, C, calculated in such a way as to act
only when the float has reached a certain definite height. At that
moment it lifts the extremity of the weighted lever, E, which in
falling back acts upon the extremity, a, of another lever, N,
pivoted at the point, O. The piece, P, which is normally in contact
with the magnet, A, being suddenly detached by this movement of the
lever, N, the induced current which is then produced causes the
display, near the pump, of a disk, Q, upon which is inscribed the word
"Full." This is a signal to stop pumping.
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