Page:Popular Science Monthly Volume 91.djvu/78

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62 Popular Science Monthly

A Drawbridge Gate Which Will Stop Any Automobile

���still further absorbed as the spring is further compressed. Before the car has gone a half dozen feet forward, all of its "push" will have been completely destroyed without producing any undue strains on the gate. The method could be relied upon to stop anything short of a railroad train!

��A runaway car striking against this gate would be stopped by the cush- ioning of the huge gate- springs in the cylinder

��DESPITE even the massive iron gates that swing across a road when a drawbridge is opened, automobiles break through occa- sionally and plunge into the river below. Such accidents occur when the brakes jam. Here was an op- portunity for an in- ventor. It was seized by Jacob Harsen, a highway engineer of New York, who has invented a cushion lock for gates. Four huge "locomotive" springs are mounted inside of four cylin- ders at the ends of the swinging gates on each side. The cylinder plungers, which work against these springs, form one piece with the gate coupling, which is locked by the gateman when the draw- bridge is about to be closed. When the automobile strikes the gate at high speed, the huge springs are slightly com- pressed ; then the gate "gives" away gradually. The energy of the automobile's impact is

���Gate locked in normal position!

��Detail of the cushioning spring. The cylin- der plungers which work against these springs form one piece with the gate coupling

��The Wooden Hand Rammer — A Survival of the Fittest

URING the last five years the electric chain rammer has disappeared from the tur- rets of modern warships. A short circuit on one of the battleships almost led to disastrous consequences. In other cases a tempora- ry breakdown spoiled the turret's chances in record firing. Gradually the old hand rammer, which in principle has changed little since Nelson's men rammed the round shot home in the muzzle loaders, has won back its supremacy. The turret of a Dread- nought is filled with other electrical de- vices, but the wooden rammer is the one bit of equip- ment that has sur- vived from the days of wooden ships, so far as the turret is concerned.

��Spring in all cylinders pressed

���The electric chain rammer was placed directly in the rear of and parallel to the bore of the turret gun

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