[Illustration:  FIG. 2.—­PLAN (Scale 1/25).]

General Description.—­Fig. 1 shows the carriage.  In the center, over the axle, is mounted a dynamo-electric, machine, D, driven by a series of gear wheels that are revolved by winches, MM.  Upon the shaft, A, is fixed a hand wheel, V, designed to regulate the motion.  In the forepart of the carriage are placed two windlasses, TT, permanently connected with the terminals of the dynamo.  Upon each of these is wound a cable formed of two conductors, insulated with caoutchouc and confined in the same sheath.  Each windlass is provided with five hundred feet of this cable, the extremity of which is attached to two lanterns each containing an incandescent lamp.  These lanterns, are inclosed in boxes, BB, with double sides, and cross braced with springs so as to diminish shocks.  Under the windlass there is a case which is divided into two compartments, one of which contains tools and fittings, and the other, six carefully packed incandescent lamps, to be used in case of accident to the lanterns.  At the rear end of the carriage there is a hinged bar, C, designed to support it at this point and give it greater stability during the maneuvers.  The stability is further increased by chocking the wheels.

[Illustration:  FIG. 3.—­HAND LANTERN (Scale 1/4).]

Maneuver of the Apparatus.—­The carriage, having reached the place of accident, is put in place, its rear end is supported by the bar, C, the wheels are chocked, and the winches are placed upon the dynamo gearing.  Two strong men selected for the purpose now seize the winches and begin to revolve them, and the lamps immediately light while in their boxes.  Another man, having opened the latter, takes out one of the lanterns and enters the dangerous place, dragging after him the elastic cable that unwinds from the windlass.  Two men are sufficient to turn the winches for five minutes; with a force of six men to relieve one another the apparatus may therefore be run continuously.

[Illustration:  FIG. 4.—­POLE LANTERN (Scale 1/4).]

The dynamo, which is of strong and simple construction, is inclosed in a cast iron drum, and is consequently protected against accident.  With a power of 25 kilogrammeters it furnishes a current of 40 volts and 7 amperes, which is more than sufficient to run two 50-candle incandescent lamps.  The winches are removable, and are not put upon the shaft until the moment they are to be used.

The windlasses, as above stated, are permanently connected with the terminals of the dynamos.  The current is led to them through their bearings and journals.  Their shaft is in two pieces, insulated from one another.  One extremity of the cable is attached to these two pieces, and the other to the lantern.  Each windlass is provided with a small winch that allows the cable to be wound up quickly.

[Illustration:  FIG. 5.—­WINDLASS (Scale 1/10).]