"Swell," said Sherman. "Now you children run along and play. We're busy. We won't be finished with this thing before tomorrow afternoon, if then."
As a matter of fact it was the next evening before Murray and Gloria were summoned back to the laboratory. The device they had seen was now mounted on a stand of its own, with long ropes of electrical connections running back from it, and had been pushed back to the end of the room. Opposite it was another stand with a two-foot square piece of sheet iron resting on a chair in its center. The lens of the big camera was pointed in that direction.
"Now," said Sherman, "watch your uncle and see what happens."
He turned a switch; the tube at the back of the apparatus lit up with a vivid violet glow and a low humming sound filled the room.
"I decided to use powdered lead in the box," he explained. "It is the heaviest metal there is available, and gives us the largest number of nuclei to project."
A second switch was thrown in and a beam of light leaped from the camera and struck in the center of the iron sheet, producing merely a mild white illumination.
"Poof!" said Gloria. "That isn't such a much. I could do that with a flashlight."
"Right you are. I haven't let her go yet. Hold your breath now."
He bent over, drove a plunger home. For just a second the only visible effect was a slight intensification of the beam of light. Then there was a report like a thunder-clap; a dazzling ball of fire appeared on the stand; a cloud of smoke, and Murray and Gloria found themselves sitting on the floor. The iron plate had completely vanished; so had the chair, all but two of its legs, which, lying in the center of the stand, were burning brightly. The acrid odor of nitrogen dioxide filled the room.