Page:Popular Science Monthly Volume 90.djvu/549

 Popular Science Monthly

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��powder charge in the center of the barrel,

and a bullet at either end of the charge

didn't kick, then a

still bigger gun with

a shell in the place

of the bullet, and an

equal weight of fine

shot or something of

the sort at the other

end of the charge,

wouldn't kick, either.

So came about the

wonderful kickless

gun, a cannon firing

a three-inch I shell

with the velocity of

1,000 feet a second,

and yet so light and

devoid of kick that

a man has fired one

in his bare hands.

There's nothing to it but what I've told you — the projectile ahead of the powder, a charge of shot of weight equal to the projectile behind the powder, two barrels joined at the charge, and no breech- closing apparatus save that which joins the tw^o barrels after loading. When the charge explodes, shell goes one way, fine shot goes the other, down its own barrel. The gun cannot kick because there is no resistance in the gun to the powder pressure, save the chamber walls at the side. The wall pressure, being the same all round, doesn't tend to move them at all. The kick is all given to the shot, which is driven out of the back barrel and which falls to the ground as harmlessly as a charge from a shotgun.

In the gun as now made, the barrels are made of the lightest, thinnest sort of vanadium steel, the strongest sort of metal. A man can easily pick up and carry the whole gun.

The throw of a lever at the center of the gun rolls over the rear barrel and exposes the

���Because the back end of the gun is nearly as dangerous as the front end, the pointer sits at the center. However, the recoil charge will not perforate a sheet of paper at seventy-five feet. The gun is made of vanadium steel

��breech end of the rifle barrel for the recep- tion of the fixed ammunition, which comes in the form of a very large cartridge with a 3-inch shell in it. This contains pow- der charge, shell and shot. Another throw of the lever returns rear barrel to posi- tion and locks it. The complete gun as originally de- signed, ran about seven feet in length. Guard studs on the pivot of the gun are easily arranged to limit the travel within safe angles.

Small shot, of course, quickly loses velocity, and the charge drops harm- lessly to earth, while the 3-inch explosive shell from the other end does the work.

���A hole-worn sink-top makes a suggestive ad- vertising sign for an enterprising plumber

��An Old Kitchen Sink Makes An Impressive Plumber's Sign

A NEW advertising idea is being used in Los Angeles, Cali- fornia. J. K. McCahan, a plumber, is attracting public attention to himself by an old, hole- worn zinc slab which he has stationed high up over a small orange tree in his front yard. The bottom of this novel shingle has been daubed over with white, and his name and his trade have been painted over this in black. No one can pass by this house without be- ing doubly impressed by the fact that here, at least, lives a wide-awake plumber. The verv' holes in the zinc plate suggest the trade of the man who lives there, without the lettering. The place for the sign was decided by the fact that the little orange tree needed propping.

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