"You will find that we greatly respect all that you have accomplished," he declared earnestly. "As for your apparatus"—glancing at the cube—"you have the advantage on the earth of certain chemical elements which are entirely lacking here, otherwise we should have called upon you long ago."
He slipped a panel of glass to one side. "Step in quickly!" he exclaimed, gasping; and the four obeyed him without thought. It was only when the panel was replaced that they noticed the floor of the cage; it was of clear glass, like the sides, and looked totally incapable of bearing their combined weight.
The Venusian smiled at Smith's worried look. "The material is amply strong enough," said he. "I am only concerned about your machine there. Is it safe to be left alone?"
"So far as we know, yes," answered Van Emmon, who did not feel quite as much confidence in the stranger as the rest.
"Then we can go down at once." With these words the man in satin turned to a small black box in one wall of the elevator and touched a button.[10]
Instantly the car began to descend, at first slowly and then with swiftly increasing velocity. By the time the explorers had accustomed their eyes to the sudden semi-darkness, the cage was dropping at such a speed that the air fairly sang past its sides.
Far overhead was a square, black shadow in the waxlike crust which they had left; it was the shadow of the cube. All about them was a dimly lit network of braces, arches and semitransparent columns; to all appearances the system seemed to support the crust. Billie whirled upon the Venusian:
"I've got it now! The whole globe is covered with glass!"
Estra smiled his approval. "For thousands upon thousands of centuries, my friend. The thing was done when our ancestors first suspected that our planet was doomed to come so near the sun. It was the only way we could protect ourselves from the heat."
"Great!" exploded the doctor, admiration overcoming regret that he had not thought of it himself. But Smith had other thoughts: