Denny forbore to ask him what It did, how It worked, what the devil It was, anyway. From his own experience he knew that the abstraction of an experimenter insulates him from every outside contact. Matt, he realized, was probably making a great effort to remain aware that they were there in the laboratory at all; probably thought he had explained in great detail his new device and its powers.
Vaguely wrapped in his fog of concentration, Matt thrust the snarling dog under the bell, which he lowered quickly till it rested on the pedestal-floor and ringed the dog with a wall of glass behind which it barked and growled soundlessly.
Completely preoccupied again, Matt went to a big switch and threw it. The dynamo hummed, raised its pitch to a high, almost intolerable keening note. The ring of pseudo-searchlights seemed in an ominous sort of way to spring into life. The impression must have been entirely imaginary; actually the projectors didn't move in the slightest, didn't even vibrate. Yet the conviction persisted in the minds of both Jim and Dennis that some black, invisible force was pouring down those conduits, to be sifted, diffused, and hurled through the lead lenses at the dog in the bell.
Thrilled to the core, not having the faintest idea what it was they were about to see, but convinced that it must surely be of stupendous import, the two stared unwinkingly at the furious hound. Matt was staring, too; but his glance was almost casual, and was concentrated more on the glass of the bell than on the experimental object.
The reason for the direction of his gaze almost immediately became apparent. And as the reason was disclosed, Dennis and Jim exclaimed aloud in disappointment—at the same time, so intense was their nameless suspense, not knowing they had opened their mouths. It appeared that for yet a little while they were to remain in ignorance of the precise meaning of the experiment.
The glass of the bell was clouding. A swirling, milky vapor, not unlike fog, was filling the bell from top to bottom.
The dog, rapidly being hidden from sight by the gathering mist, suddenly stopped its antics and stood still in the center of the bell as though overcome by surprise and indecision. Motionless, staring vacantly, it stood there for an instant—then was concealed completely by the rolling vapor.
But just before it disappeared, Jim turned to Denny in astonishment, to see if Denny had observed what he had; namely, that the fog seemed not to be gathering from the air penned up in the bell, but in some strange and rather awful way to be exuding from the body of the dog itself!