a momentary disorientation.
“Watch out—I’m going to swing around.”
Holding firmly to the rung, he used his arms to twist himself around a hundred and eighty degrees, and found himself momentarily blinded by the lights of his companions. Far above them—and now it really was above—he could see a fainter glow along the rim of the sheer cliff. Silhouetted against it were the figures of Norton and the back-up team, watching him intently. They seemed very small and far away, and he gave them a reassuring wave.
He released his grip and let Rama’s still-feeble pseudo-gravity take over. The drop from one rung to the next required more than two seconds; on Earth, in the same time, a man would have fallen thirty meters.
The rate of fall was so painfully slow that he hurried things up a trifle by pushing with his hands, gliding over spans of a dozen rungs at a time, and checking himself with his feet whenever he felt he was traveling too fast.
At rung seven hundred, he came to another halt and swung the beam of his helmet lamp downward. As he had calculated, the beginning of the stairway was only fifty meters below.
A few minutes later, they were on the first step. It was a strange experience, after months in space, to stand upright on a solid surface, and to feel it pressing against one’s feet. Their weight was still less than ten kilograms, but that was enough to give a feeling of stability. When he closed his eyes, Mercer could believe that he once more had a real world beneath him.
The ledge or platform from which the stairway descended was about ten meters wide, and curved upward on each side until it disappeared into the darkness. Mercer knew that it formed a complete circle and that if he walked along it for five kilometers, he would come right back to his starting point, having circumambulated Rama.
At the fractional gravity that existed here, however, real walking was impossible; one could only bound along in giant strides. And therein lay danger. The stairway that swooped down into the darkness, far below the range of their lights, would be deceptively easy to descend. But it would be essential to hold on to the tall handrail that flanked it. Too bold a step might send an incautious traveler arching far out into space. He would hit the surface again perhaps a hundred meters lower down. The impact would be harmless, but its consequences might not be, for the spin of Rama would have moved the stairway off to the left. And so a falling body would hit against the smooth curve that swept in an unbroken arc to the plain almost seven kilometers below.
That, Mercer told himself, would be a hell of a toboggan ride. The terminal speed, even in this gravity, could be several hundred kilometers an hour. Perhaps it would be possible to apply enough friction to check such a headlong descent; if so, this might even be the most convenient way to reach the inner surface of Rama. But some very cautious experimenting would be necessary first.
“Skipper,” reported Mercer, “there were no problems getting down the ladder. If you agree, I’d like to continue toward the next platform. I want to time our rate of descent on the stairway.”
Norton replied without hesitation. “Go ahead.” He did not need to add, “Proceed with caution.”
It did not take Mercer long to make a fundamental discovery. It was impossible, at least at this one-twentieth-of-a-gravity level, to walk down the stairway in the normal manner. Any attempt to do so resulted in a slow-motion dreamlike movement that was intolerably tedious. The only practical way was to ignore the steps and to use the handrail to pull oneself downward.
Calvert had come to the same conclusion. “This stairway was built to walk up, not down!” he exclaimed. “You can use the steps when you’re moving against gravity, but they’re just a nuisance in this direction. It may not be dignified, but I think the best way down is to slide along the handrail.”
“That’s ridiculous,” protested Myron. “I can’t believe the Ramans did it that way.”
“I doubt if they ever used this stairway. It’s obviously only for emergencies. They must have had some mechanical transport system to get up here. A funicular, perhaps. That would explain those long slots running down from the hub.”
“I always assumed they were drains—but I suppose they could be both. I wonder if it ever rained here?”
“Probably,” said Mercer. “But