Page:Popular Science Monthly Volume 90.djvu/550

 �Gun Problems

Suddenly the gun has sprung into prominence. Here are a

��Luminous front and rear rifle sights which enable a soldier to aim accurately in the dark

��Fighting in the Dark with the Aid of Rifle Night -Sights

TWELVE hours do not make a working day on the fighting fronts. Even though the grist of the day's fighting has been heavy, the belHgerents sometimes battle far into the night. This they are able to do with the aid of rifles fitted with night-sights, the invention of a British artilleryman.

The invention consists of two spring clips which can be quickly fastened to the front and rear sights of the British in- fantry rifle. On the spring clips are painted strips of luminous paint which make two rough sighting points by which to direct the rifle.

��what is

��from the carbureter just below. Pressing the trigger closes a circuit in the battery line and ignites the gas charge, driving the bullet out through the spring resistance and through the bar- rel. The pressure of such a gas charge is only about one-tenth of necessary to drive even the little

���The firing pin is released by pressure on a thumb-trigger

��A Gasoline Gun — It's Somewhat Like an Automobile Motor

THE French used to make a little gun that threw its bullet by means of car- bonic acid gas, stored in compressed form, in a reservoir carried below the barrel. When the trigger was pressed, a little valve ad- mitted a quantity of the gas to the breech end of the barrel and blew the bullet out.

Now comes an inventor with a gaso- line gun. Under the barrel is carried a reservoir of gasoline, with a car- bureter behind in the frame of the arm. Batteries are supplied in the stock. The bullet is loaded into the barrel and kept from moving forward by the resistance of a pair of springs. A plunger at the back end of the breech is used to furnish compression to the gas charge delivered by ^ valve

��.22-caliber bullet from the ordinary rifle.

Pulling the Trigger of the Gun with the Thumb

FROM the days of the matchlock, when some ingenious gun designer ar- ranged a little slip of steel under the grip of the gun by which the forefinger released the glowing match into the priming powder of the gun, the forefinger has been pulling the trigger of a firearm. One reason for this is that when the gun is gripped normally, the neces- sary spring resistance in the trigger is easiest over- come by a light increase in the grip of the upper parts of the thumb and forefinger. A Brooklyn inventor has evolved a thumb-trigger bolt action rifle in which the firing pin is released by pres- sure on a thumb-trigger on the upper part of the grip, instead of by the nor- mal form of trigger below the grip. Also he protects the thumb-trigger or plun- ger on the upper side of the grip by an open base peep-sight, mounted on the firing pin in a form familiar to owners of bolt types.

COMPRESSION CHAMBER

���The gasoline gun — an attempt to shoot a bullet by means of a gas- oline explosion

��t-CAR5UR£TtR.

��534

�� �