Page:Popular Science Monthly Volume 90.djvu/528

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��Popular Science Monthly

���A new gun, so movmted that it can be fired at the steepest angle. A perforated weight counterbalances it

��Shooting at Bird-Men with the New French Guns

IF you have ever shot ducks on the wing with a shot-gun, you have experi- enced some of the difficul- ties of the ar- tillerymen who handle anti-aircraft guns on Euro- pean battle- fields. Your practiced bird -shot aims a little ahead of his prey. Beyond this time allowance, he considers nothing. He fires point-blank at his mark.

And so it is with the man who fires shrapnel at artificial birds soaring at a height of a mile and more. His task is far more difficult than that of the duck hunter. The allowance which must be made for the movement of the air-man and the time required by the projectile to fulfill its mission is not so easily gaged as it is with a fowling piece on the ducking ground.

Before the present war, not a single anti- aircraft gun could be fired point-blank at an aeroplane in the air. The necessity of that proceeding seemed so obvious that I pointed it out more than once before 1914. That it has indeed become essential the accompanying illustration abundantly proves. Compared with this well-constructed and easily handled weapon the anti- aircraft guns with which Euro- pean armies were experiment- ing before the war, seem ridicu- lously awkward. They could not be fired point-blank, for example; they had to be sighted around a corner, as it were, inasmuch as the marks- man had to keep his eye glued on a reflecting prism. It was necessary to find the range and therefore to lose valuable

��seconds — something which is altogether unnecessary in point-blank firing.

The gun pictured, a French de- sign, is so mounted that it can be fired at the steep- est angles. It is so counter- balanced (note the perforated weight at the right) that it can be swung about with the utmost ease. The position of the marks- man shows that he sights as directly as if he were manipulating a tele- scope instead of a gun. — Carl Dienstbach.

���The hinged brackets fit the sides of the racket, holding it rigidly straight

��A New Press for Preventing the Tennis Racket from Warping

TO prevent the wood of tennis rackets from warping, a press is used consist- ing of perfectly straight brackets clamped on the racket when it is not in use. The brackets generally used to-day, however, require considerable adjustment to clamp them properly. They consist of a pair of trapezoidal pieces of well-seasoned wood which are held flat against the rack- et on either face by four wing-nuts" which clamp them down and which must be screwed to exactly the same tension.

A far simpler bracket has been invented by Fred Ricords, of Brooklyn, New York. In- stead of face brackets, two side brackets semi-elliptical in shape are used. They take the contour of the sides of the racket when closed together. The brackets .are made per- fectly straight longitudinally, and when they are fitted or the sides, they hold the wooc so that it cannot warp.

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