Page:Popular Science Monthly Volume 88.djvu/909

 Making the Burglar Chase Himself

��REASONING that the easiest wax- to dispose of a burglar is to scare him with the thing he most fears, and that is a pistol, a Chicago man, R. C. Mayberry, has devised an apparatus which will fire off cartridges and do the scaring automatically at the very mo- ment the burglar begins work.

The burglar unwittingly sets off the contrivance himself and does his own frightening, as it were. This is accom- plished through the aid of numerous push-buttons or other switches, located at points along the path a burglar must pursue in entering a building. Thus, the raising of a window will close one of the switches and cause the contriv^ance to operate. If, once inside, the burglar should stumble over a string stretched across his path or step on a loose board, a fusillade will surely greet him. As soon as he operates one of the numerous switches, his presence is prompt- ly heralded far and wide by powder, smoke, and noise.

The device is in part mechani- cal and in part electrical in nature. Housed in a small box about five inches square and ten inches long, it is preferably suspended from or attached to the ceiling of a room. Hence, it is out of the way and less accessible to would-be tamperers.

The mechanical part of the apparatus consists of a small clockwork mechanism which rings a high-pitched bell on the principle of an alarm-clock. The slow unwinding of the spring as it operates the bell, causes a cam-like contrivance to revolve, at each successive turn releasing a firing-pin on one of five .44 blank cartridges located in a metal bar nearby.

The electrical part of the mechanism comes into play in starting. The burglar's closing one of the switches causes cur- rent from dry-batteries, located within the box, to be sent through a small solenoid. This

��operates a small bolt-lock and per- mits the bottom door of th'e box to drop down, at the same time starting up the clockwork with its resulting exploding of the cartridges and ringing of the alarm-bell. As the bottom door drops down smoke from the cartridges escapes.

The burglar either departs before he has had any opportunity to secure loot, or else leaves so many clues behind in taking his ill-gotten goods along that his ready apprehension later is an easy matter. The robber has no means of knowing, of course, whether the shots are coming from a mechanical contri- vance or from an outraged householder's revolver. He never stops to inves- tigate.

���Five blank cartridges are fired in rapid succession when the window is opened

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