On the opposite side of the car the horizon ended in a sunrise glow of a slightly greenish radiance. From that side the pinkish tint of the surface was quite pronounced.
Before going any lower the doctor, struck with an idea, declared: "We always want to remember that this car is perfectly soundproof. Suppose we open the outer door of the vestibule. I imagine we'll learn something peculiar."
It was possible to open this door without touching the inner valves, using mechanism concealed within the walls. The moment it was done—the door faced the "north"—pandemonium itself broke loose. A most terrific shrieking and howling came from the outside; it was wind, passing at a rate such as would make a hurricane seem a mere zephyr. The doctor closed the door so that they could think.
"It's the draft," he concluded; "the draft from the sun-warmed side to the cold side."
As for Van Emmon, he was getting out a rope and a heavy leaden weight. On the rope he formed knots every five feet, about twenty of them; and after getting into one of the insulated, aluminum-armored and oxygen-helmeted suits with which they had explored Mercury, he locked himself on the other side of the inner vestibule door and proceeded to "sound."
To the amazement of all except Billie "bottom" was reached in less than twenty feet. "I thought so," she said with satisfaction; but she was not at ease until Van Emmon had returned in safety from that booming, whistling turmoil.
His first remark upon removing his helmet almost took them off their feet. "The point is," said he, throttling his excitement—"the point is, the rope was nearly jerked out of my hands!
"Understand what I mean? The surface is revolving!"
This upset every idea they had had; it never occurred to any of them that the planet could revolve at such speed that it would appear stationary. Smith went at once to the eastern window and watched closely, for fear some irregularity in that apparently perfect sphere might catch them unawares. They did not learn till later that Venus's day is a little less than twenty-five hours, and therefore, since they had approached her near the equator, the wind they had encountered was moving at nearly nine hundred miles per hour!
Bit by bit, though, the cube answered to the wind-pressure. Soon they noted the sun rising slowly; and by the time it was two hours high the surface, which had been whizzing under them like some highly polished top, became entirely motionless: The cube had "stopped."