FIRE-ALARM

an apparatus, mechanical, electric, and telegraphic, used for detecting fires, and for giving instantaneous notice of an outbreak. Detectors are often placed in the different apartments of a building; they ring an alarm when the temperature reaches a certain height. In jiarge towns a series of signal-boxes is distributed in different quarters from which an alarm can be immediately telegraphed to the fire-brigade station. In 1930 a fire-alarm of the loud-speaker type was in staled in Edinburgh.