FRENCH INVENTION

Otago Daily Times, Issue 22778, 14 January 1936, Page 13

FRENCH INVENTION

AN AUTOMATIC ALARM A French invention which telephones on its own account for fire brigade or police in an emergency, giving details by means of a gramophone record, was demonstrated in London recently. The apparatus (The Times says) is already installed in 30 or 40 buildings in Paris, with the approval of the prefect of police, the fire brigade, and the French Post Office.

The development of the apparatus in Great Britain is in the hands of Mr B. P. Deane, consulting engineer. In its present form this ingenious machine can be used for only one purpose, whether as fire alarm or burglar alarm. To provide for both kinds of emergency two machines must be used, though both, can be attached to the same telephone. As a fire alarm the apparatus is operated either by thermostats fixed near the ceiling or by push-buttons, so that a watchman has only to press the nearest button. With thermostats the hot air rising to the ceiling when fire breaks out acts on them and so breaks a closed circuit. An electrical relay in the apparatus at once starts a clockwork motor. This motor sets revolving a dialling drum on which are small metal discs having projections—cut by the manufacturers to suit each installation —corresponding to the letters and figures of the telephone number of the nearest fire station.

Thus the fire brigade is called up. Next a five-inch gramophone record comes into play. It bears a verbal message giving the location of the fire and all essential details in a form approved by the fire brigade and the disc repeats its message continuously for three minutes and a-half. After this the apparatus will automatically ring up a second number —perhaps the home address of the subscriber—and will repeat its message to him. As a burglar alarm the apparatus is connected with an electrical circuit in the building. A burglar who opens a door or window, takes down a valuable picture, attacks a safe or desk, or does anything else that breaks the circuit, thereby rings up the police, who learn from the gramophone message what is happening and where. The apparatus runs quite silently inside a small Bakelite casing, from which the air has been exhausted. As it will probably be hidden in the roof or under a floor, the intruder receives no warning that he has called the police. The Post Office has given consent for the apparatus to be attached to telephones on automatic exchanges. It has been demonstrated as a burglar alarm to officials of Scotland Yard, and may be described, by their permission, as “ approved by the Metropolitan Police” for their area —to which its use will bably be confined in the first instance, ~