To the cross-piece that holds the axle of the drums the inventors have added (Fig. 5) a support formed of a strip of brass, S, with whose extremity is jointed (at the lower part) a double lever, A. This latter is held in a horizontal position by a small counterpoise, i, so that the finger at the opposite extremity shall prevent the pendulum, P, from swinging.  To keep the latter in a position of rest a bent lever, n n’, is jointed to the upper part of the support, S. The longer arm, n’, of this lever is bent forward at right angles, so that it may come into contact with and repel the small rod of the pendulum as soon as the lever has been lifted by means of a small cord which is connected with the larger arm, n, and runs up to a small hook, from whence it descends and makes its exit under the clock-case.

In order to stop the clock, then, it is only necessary to pull on this cord slightly, when, by moving the pendulum to the left, it will thrust it against the inclined plane of the finger of the lever arm, A. It is clear that the extremity of the pendulum, upon striking against the finger, will depress it slightly and go beyond the projection against which it remains fixed owing to the counterpoise, i.  The fever, n n’, is brought back to its position of rest by means of a small counterpoise at the extremity of the arm, n.  When the lever, A, is depressed, the pendulum escapes and sets the clock running.  This depression is effected by means of an electro-magnet, E, whose armature, which is connected with the rod, t, t, lifts the arm, i, of the lever, and depresses A. The wires of the two bobbins of the electro-magnet end in two clamps, 1 and 2.  The second of these latter is insulated from the clock-case.  Both communicate with the extremities of the circuit in which is interposed the seismic telltale that brings about a closing of the current.  Having noted the position of the hands on the dial when the clock was running, one can deduce therefrom the moment at which the shock occurred that set the clock in motion.

In addition to the parts that we have described, there are other accessory ones, R R_r_, and a third clamp, 3, which constitute a sort of rheotome that is designed to keep the circuit closed after the momentary closing that is produced by the telltale has occurred.  This little mechanism is indispensable when the disturbed telltale has also to act upon an electric bell.  This rheotome, which is very simple, is constructed as follows:  A small brass rod, R, which is screwed to the support, S, carries at its left extremity a brass axis, X, which is insulated from the rod, R, by means of an ivory piece.  Toward the center of this small rod, the bent lever, r, carries a small arm that is bent forward, and against which abuts the axis of the pendulum, thus causing it to be thrust toward the left when the pendulum is arrested by the projection of the finger, A. As soon as the pendulum is set free, the lever, r, redescends and places itself against the axis, X. This latter communicates with clamp 3, which is insulated, while the rod, R, communicates with clamp 1.  The external communications are so arranged that the circuit in which the bell is interposed remains definitely closed when the lever, r, is in contact with the rod, X.