"Condensed moisture," explained Bennie. "We never could have made this trip without it!"
With the greatest caution, they finally succeeded in filling all the cylinders, and Burke and Atterbury started to don their vacuum armor. Bennie was about to do the same, when he noticed an expression of disappointment on Rhoda's face.
"You go!" he said. "I've got to fix up something inside. Go out along with the others and look around. I'll take my turn when you come back. You won't want to stay long, I guess!"
"Oh, thanks!" she cried. "I do want to see what the moon is like!"
The men had by this time got into their strange costumes, but Rhoda found the arrangement of her skirts more or less complicated and was forced to retire to the galley, where she finally adjusted her attire to lunar requirements. Then, all four of them rolled the huge cylinder of uranium into the air-lock, and Atterbury closed and fastened the inner air-tight door behind them. They stood crowded together for a moment in that confined space, like divers in a divingbell, unable to speak to each other, and fully mindful of the fact that they were about to essay an experiment in physics never before attempted or even conceived of—the entry of a human being into a perfect vacuum.
Atterbury made a gesture of inquiry, and the others nodded their helmets. He raised one hand in warning and placed the other upon a valve in the outer door and pressed it quickly down. With a shriek, the air in the lock rushed through the valve into space, and their suits swelled perceptibly from the pressure of the contained air, as if pulled outward from their bodies by some invisible force. They stood motionless for several minutes to accustom themselves to their strange environment, making futile grimaces at one another through the glass of their helmets. Then Rhoda was startled by a curious fluttering or palpitation just above the top of her head—a sort of metallic twitter like that which might be expected to emanate from a mechanical bird—and she turned a startled face toward Burke, who only grinned in response and pointed to the escape-valve upon his own helmet. Then she remembered that he had previously explained to her how the vitiated air inside the helmets must needs escape in order to give place to the new fresh air liberated by the supply-tanks. But, in spite of her knowledge that this fluttering was due simply to a necessary device, she never heard it without a momentary tremor of fear—a sudden conviction that her soul was unexpectedly starting upon the Great Adventure.
The air-lock having emptied itself of its contents, Atterbury now released and opened the outer door and lowered a small metal landing-stage, from which hung the steel ladder. Then, with some difficulty, owing to the clumsiness of their new garments, the two men climbed down upon the tufa-like surface of the moon, while Rhoda remained watching them curiously from above. Apart from the puffing-out of the rubber suit, she experienced no new sensations, for she breathed with perfect ease, and the sunlight, falling full upon her body, warmed her through and through.
Down below, Atterbury and Burke at first amused themselves by experimenting with the force of lunar gravitation, so much less than that of the earth, and jumped hither and yon—distances of fifteen and twenty feet at a single bound, like mountain-goats leaping from crag to crag. Once having accustomed themselves to their surroundings and their loss of gravity, they climbed up the great tripod and commenced to rig the block and tackle with which they planned to hoist the fresh uranium cylinder to the top of the skeleton tripod and replace their now exhausted supply of fuel.
