"QX if you like. Just so you keep the kitty fed." "We'll feed her!" and the game went on. Chunks of débris--some rock, but mostly solid meteoric nickel-iron--shot toward the vessels and the ravening sphere, becoming inertialess as they entered a wide-flung zone. Pressors seized them avidly, pushing them through the interstices of the framework, holding them against the voracious screen. As they touched the screen they disappeared; no matter how fast they were driven the screen ate them away, silently and unspectacularly, as fast as they could be thrown against it. A weird spectacle indeed, to see a jagged fragment of solid iron, having a mass of thousands of tons, drive against that screen and disappear! For it vanished, utterly, along a geometrically perfect spherical surface. From the opposite side the eye could see the mirror sheen of the metal at the surface of disintegration! It was as though the material were being shoved out of our familiar three-dimensional space into another universe--which, as a matter of cold fact, may have been the case. For not even the men who were doing the work made any pretense of understanding what was happening to that iron. Indeed, the only entities who did have any comprehension of the phenomenon--the forty-odd geniuses whose mathematical wizardry had made it possible--thought of it and discussed it, not in the limited, three-dimensional symbols of everyday existence, but only in the language of high mathematics; a language in which few indeed, are able to really and readily to think. And while the crews became more and more expert at the new technique, so that metal came in faster and faster--huge, hot-sliced bars of iron ten feet square and a quarter of a mile long were being driven into that enigmatic sphere of extinction--an outer framework a hundred and fifty miles in diameter was being built. Nor, contrary to what might be supposed, was a prohibitive amount of metal or of labor necessary to fabricate that mammoth structure. Instead of six there were six cubed--two hundred and sixteen--working stations, complete with generators and super-Bergenholms and screen generators, each mounted upon a massive platform; but, instead of being connected together and supported by stupendous beams and trusses of metal, those platforms were linked by infinitely stronger bonds of pure force. It took a lot of ships to do the job, but the technicians of the Patrol had at call enough floating machine shops and to spare. When the sphere of negation grew to be about a foot in apparent diameter it had been found necessary to surround it with a screen opaque to all visible light, for to look into it long or steadily then meant insanity. Now the opaque screen was sixteen feet in diameter, nearing dangerously the sustaining framework, and the outer frame was ready. It was time to change.