REPORT OF MR. ROBERT B. LINES.
4G9
In 18G9 Mr. Hall patented a method of using his signal and alarm apparatus, before described, at highway crossings, the electric circuits in this case being controlled by the moving train, through the agency of levera placed in close proximity to the rails, and in such a position as to be depressed by the wheels of the train as it passed.
This object may also be accomplished by means of a combination of the " automatic whistle ” contact with a " sonnerie,” and, if necessary, with a Pope’s or Ilohenegger’s semaphore.
In case both the sonnerie and the semaphore are employed, the latter only need be actuated by the momentary current, and the arm or disc may be used to close a local circuit which shall actuate the sonnerie until the semaphore is again changed.
If the aural signals are thought to be sufficient, then a relay must be introduced like the magnet of the "automatic whistle,” the armature of which shall keep the secondary circuit of the sonnerie closed until a current in the opposite direction to the first, reverse the position of the armature.
If the automatic whistle, as well as its brush contact, were employed on the engine, it would serve, of course, as an additional alarm to the traveller on the highway, and would warn the engineer as well that he was approaching a crossing.
Plate XII. shows the arrangement of the circuits for both a sonnerie and semaphore signal. The Hoheneggcr semaphore is shown, that being adapted to momentary signals ; with some such modification as that suggested, however, the Pope system could be used equally as well.
Plate XII.
Locomotive to ground.
"nr—.
The train approaching in the direction shown by the arrows, closes at A the circuit of the semaphore, which, turning, closes the local circuit of the sonnerie. Then passing the crossing of the highway and touching the fixed contact B, it turns the arm of the semaphore back to " line clear,” the local circuit opens, and the sonnerie ceases to ring.