Popular Science Monthly/Volume 88/January 1916/Indicator Tells Pursuing Police Speed of Automobile
Indicator Tells Pursuing Police Speed of Automobile
LAW-ABIDING motorists who have had the disagreeable experience of being arrested when they were well within the limit of the law will doubtless greet, with delight, the new invention of a Pennsylvania inventor. By means of a speed indicator, similar to the indicators which are found on the instrument boards of nearly every car, the inventor has made a combination license tag holder and speed indicator which shows clearly to the public the number of the car, as well as the exact speed at which the car is traveling.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/PSM_V88_D103_External_speed_indicator_of_an_automobile.png/250px-PSM_V88_D103_External_speed_indicator_of_an_automobile.png)
Here is a chance for
the honest motorist to
tell everybody how fast
he is running
A semicircular plate, with the numbers in multiples of five up to thirty miles an hour, is equipped with a pointer, which indicates accurately the speed of the car. Both the license tag and the indicator plate are perforated, and are illuminated at night by means of a light placed behind them.