going to shoot through that, do you?"
asked Ned in surprise.

"Surely. The electric bullets will pierce anything. They'll go
through a brick wall as easily as the x-rays do. That's one valuable
feature of my rifle. You don't have to see the object you aim at. In
fact you can fire through a house, and kill something on the other
side."

"I should think that would be dangerous."

"It would be, only I can calculate exactly, by means of an automatic
arrangement, just how far the charge of electricity will go. It
stops short just at the limit of the range, and is not effective
beyond that. Otherwise, if I did not limit it and if I fired at the
scarecrow, through the piece of steel, and the bullet hit the
figure, it would go on, passing through whatever else was in the
way, until its power was lost. I use the term 'bullet,' though as I
said, it isn't properly one."

"By Jove, Tom, it certainly is a dangerous weapon!"

"Yes, the range-limit idea is a new one. That's what I've been
working on lately. There are other features of the gun which I'll
explain later, particularly the power it has to shoot out luminous
bars of light. But now we'll see what it will do to the image."

Tom took his place at the end of the range, and began to adjust some
valves and levers. In spite of the fact that the gun was larger than
an ordinary rifle, it was not as heavy as the United States Army
weapon.

Tom aimed at the armor-plate, and, by means of an arrangement on the
rifle, he could tell exactly when he was pointing at the scarecrow,
even though he could not see it.

"Here she goes!" he suddenly exclaimed.

Ned watched his chum. The young inventor pressed a small button at
the side of the rifle barrel, about where the trigger should have
been. There was no sound, no smoke, no flame and not the slightest
jar.

Yet as Ned watched he saw the steel plate move slightly. The next
instant the scarecrow figure seemed to fly all to pieces. There was
a shower of straw, rags and old clothes, which fell in a shapeless
heap at the end of the range.

"Say. I guess you did for that fellow, all right!" exclaimed Ned.

"It looks so," admitted Tom, with a note of pride in his voice. "Now
we'll try another test."

As he laid aside his rifle in order to help Mr. Jackson shift the
steel plate there was a series of yells outside the shed.

"What's that?" asked Tom, in some alarm.

"Sounds like some one calling," answered Ned.

"It is," agree