That second compartment, we found, was a replica of the first, being of the same size and holding within it several dozen more of the pear-shaped water-manufacturing mechanisms. We passed through it, therefore, over the dust-strewn paving and through the low similar door on its opposite side, to find ourselves in still another compartment of water-manufacturers. Pressing on, rapidly becoming able to pass through the low strange doors easily in our cumbrous space-walkers, we passed through a half-score more of similar compartments all holding only the dust-covered, pear-shaped water-mechanisms, and then at last we passed into a different compartment, one that held a strange shelving that covered all its walls, at which we stared in perplexity for some time.
This shelving consisted of horizontal and perpendicular shelves of smooth black stone like that of the walls themselves, running along and up and down those walls and forming thus a continuous series of box-like openings, each some four feet in length and two in height. There were hundreds of these shelves in the compartment, we could see, yet all of them were quite empty, and in the compartment there seemed to be no other object. They suggested the equipment of a store-room, yet there was no faintest clue as to what had been stored in those shelf-tiers of openings, ranged one above the other all around the walls. Had Marlin and I been able to guess the astounding truth as to those tiers of compartments as to their significance and purpose, much would have been clear to us right then. As it was, after vainly endeavoring to fathom the purpose of the things, we gave it up and moved on out of the compartment, and through similar shelf-tiered compartments beyond it.
By this time we had passed some distance from beneath our hovering space-flier, but still could see its gleaming polyhedron hanging high in the air behind us. Reassured by the sight of it, we passed on, and in the next half-hour progressed through many more compartments. Some of these contained water-manufacturing mechanisms or tiers of strange shelf-openings such as we had already seen. But many others held mechanisms or objects strange to our eyes, before which Marlin and I stood entranced. We almost forgot, in the overpowering interest of the things that we found in those compartments, the object of our exploring search through the strange compartment-city, our search for clues as to the beings of Neptune and as to the great force-ray that was turning the sun ever faster.
Compartments we found in which were structures that puzzled us as completely as had the tiers of shelf-openings. These structures were great flat metal containers, each scores of feet in length and width but hardly more than a foot or two in depth. They were ranged one above the other in great supporting frameworks, and each container was filled with black fine soil. The compartments that held these had set in their walls great white disks which were connected to intricate apparatus that seemed generators of some kind of force, but more than that we could not ascertain from our inspection of them. The whole arrangement, the great shallow containers of soil, the disks in the walls, the generators connected to them—all was utterly enigmatic and perplexing to us, and we were forced to give up the riddles and pass on into other compartments, in which were other things almost as mysterious.
Some held giant globes of burnished metal, now dust-covered, which occupied almost a whole compartment each. These great gleaming globes were among the most puzzling things we had found, since there was, in the compartment of each one, no other object or indication of their purpose, save for a few switches mounted upon a panel, the combination of which we could not discover, opening and closing them in vain. We had seen these great globes from above, dotting the vast compartment-city here and there in great numbers, but we could learn no more of their purpose standing there beside them than we had been able to guess from above. And near these there were strange looming machines, many-cogged and with a great hopper above whose purpose we guessed, at least, guessing that these were the mechanisms that produced from some raw materials the artificial diamond-hard black stone-material that made up all the intersecting walls of this strange huge city-world.
Each of these machines had before it a very low, round metal seat, with in front of that seat the controls of the machine, a half-dozen burnished metal levers. As we saw them Marlin and I exchanged startled glances. Had the being who operated that machine, who sat before it, held and operated all those control-levers of the mechanism? Back to our minds flashed the strange low openings of the doors through which we had come, and for a moment the same strange sense of dread chilled me. But I shook off the feeling, followed Marlin on into another compartment, glancing back through to where our space-flier poised in the air now far across the city behind us.
It was into another long rectangular compartment that we passed, one that held, like that out of which we had just come, rows of strange many-cogged mechanisms. But one feature of that compartment caught our attention instantly, held us motionless and staring. And that was that those rows of great mechanisms were not complete! Here and there in those rows were gaps, as though machines had been removed from the compartment, and where those gaps were, where the missing machines had stood, were squares on the floor where their bases had rested, squares that were entirely free of the inch-thick dust that lay over all else! And even as we stared, as we comprehended the astounding significance of that, we saw that upon the dust-coated floor before us were many tracks, small round and strange tracks in the thick dust that were of great number and that had been made, it was apparent from their dust-free condition, but days or hours before!
"Marlin!" I whispered, grasping my companion's space-walker with the great metal arm of my own and touching head casing to head casing. "Marlin—those tracks—someone, something has been here—and but recently!"
"It can't be!" he exclaimed, his voice hushed strangely like my own. "Neptune—all this great compartment-city—it's all dead, deserted——"