"Why not?" he reflected. "There's no reason why there shouldn't be frozen water in this debris. Presumably the general mass is constituted of the same rock, minerals, and gases as the other planets, including Earth. Some of it could be frozen air--or its constituent gases--considering the absolute zero out there." He recalled reading the contention of Halbfass that some earth hailstorms originate in outer space. The scientist had produced considerable data in support of his theory that such bombardments may be of stellar origin. There was the case of an iceberg twenty feet in diameter, reported from Dharwar, India, in 1838, and a still earlier case of a block of ice "as big as an elephant" which reputedly fell in the same region during the days of Tippoo Sahib. Unless Marlin was mistaken there were celestial icebergs among the growing mass of planetary debris circling the sphere. The picture he had envisioned of the planetoid bodies closing in on the sphere, with its augmented gravitation, had seemed at first fantastic. It was taking on more and more the aspect of grim, threatening reality. Collisions between bodies in the surrounding space became more frequent as their orbits definitely spiraled inward. Once a fragment drifted so close that it almost seemed to graze the sphere. As Marlin tensed for the seemingly inevitable impact, it passed by. But on its return would it not be materially closer? That particular fragment did not return. Perhaps it collided with another and was pulverized or deflected from its course. But the sphere might not escape so easily the next time. Occasionally, his vision would be obscured by what seemed to be a cloud of dust. It was undoubtedly just that--a field of particles from the grinding and colliding of rock masses, settling toward the gravitational pull of the sphere. On another occasion, the obscuring cloud appeared to be sleet--a mass of iceberg fragments, or perhaps more tenuous gas in solidified form. * * * * * Since that one shuddering outburst, Norma had seemingly regained her self-control. She appeared only occasionally at meal times, tight-lipped, reserved. Often Marlin saw her standing on a secluded part of the superstructure, wrapped in her moody thoughts. She climbed one day to the observation platform beside him. "What can you see through that thing?" she asked. "Take a look," he invited. "It's terrifying, but inspiring too--when you reflect that mortal eyes never looked upon it before." She studied the awesome prospect for a minute, then drew away, shivering as if with cold. "Give it to me straight," she demanded. "What's the payoff? Here we are in a thin-shelled bubble floating through a tumble of jagged rocks and icebergs. They're drawing closer all the time, aren't they?" He temporized. "My biggest worry right now is that the dust fragments, settling down on us, will bury the periscope head. That will be the last of our observations."