Page:Popular Science Monthly Volume 89.djvu/586

 572

A Danger Signal Which Compels Attention

ONCE upon a tinu- it was possible to stand on the corner of a reputed dangerous thoroughfare in a large city or e\'en in the large towns and especially at railroad cross- ings and experience many of the thrills of melodrama at the narrow escapes of pedestrians and vehicles from accidents. But to-day so many precautions are taken and danger signals arc so ninniTous and so cleverly planned that the number of accidents is mini- mized.

An electric signal has been designed for a danger- ous corner where obstruc- tions, such as trees and buildings close to the side- walk or fences, shut off the view of approaching street- cars on a cross street from vehicles on the main street until it is almost too late to i)re\'ent serious accident.

The cross-piece on top of the signal - post is connected by wire with a magnet over which the wheels of the car pass as it nears the corner. This contact of the wheels with the magnet sets the cross- I)iece in motion, and it continues to oscillate, (lasiiing its brilliaiU colors insistently, until the car wheels have come in contact with a lever on the other side of the danger zone, the press- ure upon which has released the signal wire. This serves as a reminder to tlir motorman to slow up as he nears the corner and as a warning to ]x>destrians and drix'crs of vehicles that a car is approaching.

At night the word D.'XNGKR shines out in ihuminated red letters, the lights being enclosed in the bo.\ on which the lettering apjjears. A space is also re- served for the name of the crossing streets, making the sigiial-i)st a sign- post as well. The colors I'mployed are eye-conipc-lling, and the de\'ice has [)roved to be an eflicii'nl guardian of the public safety at that |)arliiiil.ir coiiur which has no traflic policeman.

��Popular Science Monthli/

���Thi- hi illi.iiit colors and the revolving cross-piece cannot fail to attract

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��A Safety- Bicycle for the Timid '4 Fat Man

THE fat man who wants to reduce by bicycling but ho does not want to fall oflf and injure himself in the at- tempt, can now ride with safety on a bicycle fitted with a new rear attachment which will prevent him from losing his balance.

The frame of the bicycle carries an extra pair of small wheels at the back alongside the rear wheel. When these are attached it is no effort to maintain one's balance. Moreover the- new attachment makes it easier to mount and dismount.

The wheels are so small that they are scarcely noticeable to the casual observer. Besides the feel- ing of security which their perfect balance gi\es, they also share the weight.

���How could any one fall ofT if his wheel is constantly propped up?

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