INTERESTING MOTOR DEVICES.

Shannon News, 18 October 1927, Page 4

INTERESTING MOTOR DEVICES.

A pistol attached to the running . " board and firing a special cartridge 3 filled with coloured powder is the lal- : -' est device for use in tesur-g the braking of cars. The pistol is clamped so that it points straight at the ground just ahead of the back wheel. A. cord ] ' running in pulleys connects the trigger with the brake pedal. When the brake is depressed the pistol fires the colour-

ed powder on to the road. The distance to where the car pulls up is then easily measured with absolute accuracy. This automatic indication is essential for accuracy. At a speed of 41. miles per hour (58ft per sec), a delay : - of one-fifth of a second in the driver's ; - action as following his intentions, would cause an error of 12ft in the measured stopping distance. \ For the removal of nails, spikes and : other metal debris from its roads, certain UjS. Highway Departments equip all of their road vehicles-with powerful 22in lifting magnets. These are :• suspended on either side between the iJ front and rear wheels of the trucks, IJ at a height of about sin from the road v - surface. Ourrenlt for the magnets is "; - furnished by a live-kilowatt direct curTent 115-volt generator, carried on the

truck body. ; During a trial run over 100 miles of ;;. road, the magnets on one truck coliy lected 13701 bof nails, spikes and scrap !'. Iron. An examination of the colleci . tion showed that there was an average

V of 45 pieces of sharp-pointed metal to '; every\mile of road metal just ready to :>"' puncture, and possibly ruin, the tyres f. of guileless motorists. Bunning around ';[,'. Carson City, a truck picked up 48501 b pi . of nails, etc., in two days.

if- These figures seem almost incredible, *'*. but those motorists who have had the f- -, misfortune to pick* up nails in their %W ' tyres—and there are few who haven't ?>. —Avill readily believe them. The clear- ?! '-' ' ance of Dominion roads in like man\s:': ner would be a boon. Uv.