From the pages of the Del Norte Triplicate, January 1950.
A new driver training aid, a brake reaction detonator built by Paul Barton, driving instructor and metals teacher, is aiding Del Norte High students in learning the distance required for a moving car to stop. The detonator is a complicated device that fits on the front bumper of the high school’s driver training car.
The device is set off when the driving instructor pulls a rope causing a blank cartridge in the detonator to explode as a signal for the student driver to apply the brake. When the student’s foot hits the brake, a second cartridge goes off. Each exploding cartridge discharges a piece of chalk which leaves a mark on the road where the student received the signal to stop and the exact spot where the brakes were applied. Thus the distance required by a moving vehicle to come to a complete stop is vividly demonstrated to the student.
Driving instructors hope the new detonator will aid students to become more speed-conscious and to develop more cautious drivers. In developing the detonator, Barton modified an old set of plans set up by a San Jose college student.