Blaine grunted wordless assent. The globe that was Io rushed in to meet them, growing ever larger in the field of the telescope. Now it appeared that there were tiny seams in the smooth surface, a regular criss-cross pattern of fine lines that looked like—Lord, yes, that was it! The body was constructed from an infinite number of copper plates, riveted or brazed together to form a perfect sphere.
"Why, the thing's made of copper!" Blaine gasped. "Copper plates. It's a man-made world; artificial. But where are the inhabitants?"
Antazzo laughed uproariously. "Not man-made, my friend," he corrected, "but preserved by man for his own salvation. A dying world, it was, and the cleverest scientists in the universe saved it and themselves from certain death. What you see is merely a shell of copper, the covering they constructed to retain an atmosphere and make continuation of life possible—inside."
"Your people live inside that shell?" Blaine was incredulous.
"What else? We must have air to breathe and warmth for our bodies. How else could we have retained it?"
It was staggering, this revelation. The young pilot could not conceive of a completely enclosed world with inhabitants forever shut off from the light of the sun by day and from the beauties of the heavens by night. Yet here it was, drawing ever nearer, a colossal monument to the ingenuity and handiwork of a highly intelligent civilization who had labored probably for centuries to preserve their kind. A titanic task! Who could imagine a sphere of metal more than twenty-four hundred miles in diameter enclosing a world and its peoples? A copper-clad world!
They were coming in close now, and the gravitational pull of the body made itself felt. Blaine was busy with the controls, sending tremendous blasts from the forward rocket-tubes to retard their speed for a safe landing. The incredibly smooth copper surface was just beneath them, stretching miles away to the horizon in all directions.
The inductor compass was functioning. Evidently Io possessed as strong a magnetic field as did the inner planets. Antazzo now consulted a chart which he drew from his pocket, and examined minutely the surface over which they were speeding. Here and there curious designs were etched on the copper plates, and it was from these he determined their course. Obviously there was an entrance to this sealed-in world.