REPORT OF MR. ROBERT B. LINES.
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provided with a detent, serving to retain it in this position after the train has passed. When the train arrives at the next signal, this operation is repeated, and at the same time a second circuit is closed, running back to the first-mentioned signal, and releasing or reversing it. Thus each train is supposed to maintain a danger-signal at least a mile in the rear at all times.
Although this system dispenses with the expense of attendants, it still requires two wires, the lever is liable to be displaced by the shock of passing trains, and the failure of a wire or battery may cause a failure to display the danger- signal at a critical moment. Like previous systems, it does not provide for the breakage of a train, and it is not adapted, without considerable modification, to a single track railroad, it being what is called a "non-following,” but not a "nonmeeting” block. The system which seems to obviate these objections the most completely, has been produced by Mr. F. L. Pope, of the Electric Railroad Company of New York.
Mr. Pope’s system is based on the electrical law, that a current will divide itself between two conductors, in proportion to their respective conducting capacity, and by numerous carefully conducted experiments, he found that the conductivity of a mile or more of ordinary fish-jointed rail exceeds that of the cross-ties and ballast between the tracks, even in very wet weather. Bearing this fact in mind, it will be easy to understand the system.
Plate XVI.
7 HACK
In Plate XVI., A A represents a railway track. One rail forms a continuous conductor, while the other is divided, electrically speaking, into sections, by means of insulated joints a a 1 a 2 . The long sections a a 1 are a mile.or more in length, while the alternating short sections a 1 a 2 are only