easily be destroyed by a force applied to it in such a way that
it should simply increase the swing of those vibrations up to the point
of destruction.

Now Mr. Edison had been able to ascertain the vibratory swing of many
well-known substances, and to produce, by means of the instrument which
he had contrived, pulsations in the ether which were completely under his
control, and which could be made long or short, quick or slow, at his
will. He could run through the whole gamut from the slow vibrations of
sound in air up to the four hundred and twenty-five millions of millions
of vibrations per second of the ultra red rays.

Having obtained an instrument of such power, it only remained to
concentrate its energy upon a given object in order that the atoms
composing that object should be set into violent undulation, sufficient
to burst it asunder and to scatter its molecules broadcast. This the
inventor effected by the simplest means in the world--simply a parabolic
reflector by which the destructive waves could be sent like a beam of
light, but invisible, in any direction and focused upon any desired point.

Testing the "Disintegrator."

I had the good fortune to be present when this powerful engine of
destruction was submitted to its first test. We had gone upon the roof
of Mr. Edison's laboratory and the inventor held the little instrument,
with its attached mirror, in his hand. We looked about for some object
on which to try its powers. On a bare limb of a tree not far away,
for it was late in the Fall, sat a disconsolate crow.

"Good," said Mr. Edison, "that will do." He touched a button at the
side of the instrument and a soft, whirring noise was heard.

"Feathers," said Mr. Edison, "have a vibration period of three hundred
and eighty-six million per second."

He adjusted the index as he spoke. Then, through a sighting tube, he
aimed at the bird.

"Now watch," he said.

The Crow's Fate.

Another soft whirr in the instrument, a momentary flash of light close
around it, and, behold, the crow had turned from black to white!

"Its feathers are gone," said the inventor; "they have been dissipated
into their constituent atoms. Now, we will finish the crow."

Instantly there was another adjustment of the index, another outshooting
of vibratory force, a rapid up and down motion of the index to include
a certain range of vibrations, and the crow itself was gone--vanished
in empty space! There was the bare tw