New Burglar Alarm Set Off by Vibrations of Heartbeat (Jan, 1933)
New Burglar Alarm Set Off by Vibrations of Heartbeat
THERE have been numerous inventions to foil bank bandits in their hold-up attempts but the latest one is the most original. The vibrations of the human heart-heat set off an alarm bell.
The device, shown in photo at the left, incorporates principles of electricity and accoustics to do its detecting job. It is the result of three years of work by the inventors.
In appearance, the burglar alarm resembles a miniature radio. If any would-be bandit approaches close to the cage, his heartbeat, working faster than usual because he is under a high nervous tension, will set off the boisterous alarm bell that can be heard a block away.