Page:Popular Science Monthly Volume 91.djvu/566

 Photographing the Jolts of an Automobile

��How you can tell what shock- absorber is most efficient

��One of the Many Records Obtained

��The two top lines are made by the' lights worn by the passengers and show the jolts to which those in the front and rear seats were subjected; the lower four lines show the movement of the car when overriding

��an obstruction. It is evident that the passenger in the rear seat is thrown up and down more violently than the passenger in the front seat, and that the passengers are tossed up more than the car itself

��EVERY one of the hundred odd manu- facturers of shock absorbers, tires, and springs claims that the applica- tion of his particular device to the auto- mobile will give the greatest possible ease of riding. Now comes Mr. W. C. Keys, an experimental engineer, with a method of visibly recording the effect of jolts on a car and of ascertaining to what extent shocks are absorbed.

Electric lights are mounted on the front and rear hubs, the front and rear fenders and on the passengers. The lights are turned on, and the car is driven at night across the field of a, 'camera.

The record obtained shows accurately the path of travel of every critical part of the

��car as well as of the passengers. Study the photographic record which appears on this page. The two top lines are made by the lights worn by the passengers, the topmost line representing the passenger in the rear seat and the one immediately below it rep- resenting the passenger in the front seat. The other lines are made by lights fastened on the car.

The four lower and straighter lines rep- resent the riding qualities of the springs and tires. The two top lines sum up the riding qualities of the car and show the effect of the passengers' position in relation to the axles, of the trimming of the seat cushions, of the flexibility of the frame, etc., in addi- tion to the effect of the tires and of the

���The Disposition of the Lights

��Lights were attached to the car on the hubs, on the fenders, on the body, and on the passengers as here

��shown. Beneath the car appears the obstruction which the car had to override in making the experiments

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