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EXPOSITION AT VIENNA.
Plate III.
The first of these belongs to that class of which I have spoken, as having such an important bearing on the future of railway signalling; i. e., electrical signals between stations and trains in motion. Although rude in its construction, and destined, doubtless, to be superseded by better methods, it illustrates the principle, on which, it seems to me, signalling in America must be carried out, if at all. Where labor is so scarce, and the demand for reduced rates of transportation so urgent as in the United States, we cannot expect railway companies to protect their tracks, by placing at short intervals, agents and signal-houses such as line the roads of Europe. Moreover, if the use of machinery is safe and expedient, the safest and best is that which, under proper guards, leaves as little to human agency as possible. I will not, however, enlarge upon this point at this stage of my report.
The apparatus alluded to is that employed by the Com- pagniq du JSford , near Mauberge, in France. It consists simply of a heavy spring or lever a, Plate III., securely fastened to the side of the rail in such a position as to be pressed down by the flange of a driving-wheel passing over it. The spring when depressed, pushes down a rod r, which is bent at right angles, and which carries at its end a flexible piece of metal m. This piece of metal w hich is connected with a line wire l , presses upon the standard s, which is connected to the ground. The arm ot the rod r is attached to the under side of a small pair of bellow’s 6, inclosed in a box beneath the track, as shown in the diagram. When the circuit is closed through m and s , the bellows is forced open, and closing only gradually, prolongs the signal given on the distant " bell-sounder,” w T hich would otherwise last only so long as the lever a is depressed.
The bell is of the class knowm as the sonnerie a trembleur, or trembling-sounder. Its construction is similar to that of the simple "bell-sounder” before described, wfith this exception ; that the circuit is arranged so that as soon as the hammer strikes the bell, it furnishes a shorter route for the current than through the helices of the magnet, or. as it is termed,