NEW BRITISH FIRE ALARM.
W. S. Freece, chief of the British post telegraph system, and other experts have indorsed as effective, simple, and instantaneous” a new fire alarm system, whose detector is a copper wire running near the ceiling, the whole length of the room. At its centre a small carbon is suspended over a pair of platinum terminals, all suitably protected and hardly perceptible, and when the temperature implying danger is reached, the inevitable expansion of the wire allows the carbon and platinum to close an electric circuit, which instantly sets the alarm gong ringing, and automatically telegraphs to the nearest fire station. Upon an indicator the position and extent of the oubreak are shown, and, if it spreads, its course is indicated. Non-oxidising dustproof contacts and reliable Morse transmitters are employed, and. if preferred, a closed circuit can be opened by the same device. It is claimed that this is the only system not tied to an unalterable call point, which provides for natural heat fluctuations, due to seasons, industrial operations, grate fire or illuminants. This is effected automatically and inevitably by the obedience of a metal counterpoise to the laws of expansion and contraction which govern the detecting wire and which raise the signaling point in summer and reduce it in winter. A fire breaking out affects the wire before its counterpoise, while a seasonal or gradual rise or fall produces unison of movement, and there is the same approximate margin between the normal temperature and danger at all times and seasons of the year. No fixed alarm point can do justice to winter as well as summer.