Doubting still, Professor Palmer grasped the rungs, fully expecting to find the vast bulk an immovable weight.
To his intense surprize it rose from the floor as if it were an air-filled balloon! He had exerted himself not the slightest bit. The Sphere had simply risen at his first slight lift, and had continued to rise until a slight tug upon his arm stopped it. He extended his right arm, still gripping one rung. The Sphere followed easily, its only resistance apparently that of the atmosphere surrounding it.
“Now release it,” suggested Robert.
The astonished professor did so, half expecting to see it crash to the floor.
But nothing of the sort occurred. For several seconds the giant ball continued to rise very slowly, like a sluggish soap-bubble. Doubtless he had unwittingly allowed his hand to waver slightly when releasing it.
Then very, very slowly the Sphere began to descend, finally settling softly and with scarcely a sound. Though it had been but a few feet above the floor, it required fully a minute to come to rest. One noticeable feature was its vertical stability. It neither rolled in its descent nor wobbled in settling, but simply came down with a paradoxical combination of majestic ponderance and zephyrlike softness.
“Remarkable!” ejaculated the professor, feeling the inadequacy of the word when applied to this marvelous achievement.
“The rigid stability,” Robert explained, “is automatically controlled by a delicate device attached to the central upright gyroscope.”
“I was under the impression that the entire apparatus was unaffected by gravity.”
“This device is the exception. The Sphere’s weight is neutralized to an absolute minimum by the gyroscopic control, but it was necessary to maintain one point of gravitational contact in order to establish some permanent upright stability; otherwise, the Sphere would revolve at random when in midair.”