That object was a great gleaming metal polyhedron that loomed in a supporting framework beside us like a huge ball-like faceted crystal of metal. This great faceted ball of metal, though, was fully thirty feet in diameter, and here and there in the great, smooth, faceted, plane-surfaces of it were set hexagonal windows of clear glass, protected by thick raised rims of metal around them. There were also set in six of the facets six round openings a foot in diameter, one of these being in the faceted ball's top, one in its bottom, and four at equi-distant points around its equator. In one of the flat facet-sides, also, was a screw-door of a few feet diameter that now was open, giving a glimpse across a small vestibule-chamber inside through a second open screw-door into the great polyhedron's interior. That interior seemed crowded with gleaming mechanisms and equipment, attached to the inner side of the great metal shell. Marlin was contemplating the great thing intently as we stood there on the roof beside its supporting framework. "Finished--in three more days," he repeated. "Everything's ready for the last generator." "That will be done in two days more," said Randall, beside me. "Everything else at the World Government's laboratories has been suspended in order to get these generators ready for us." "They've worked fast to get three of the generators in the flier already," Marlin acknowledged. "Especially since Whitely here, in directing them, had only his own first crude models to work on." "Lucky we are to get the generators completed and the space-flier finished in the month we estimated!" I exclaimed. "If the whole world hadn't centered its energies on the space-flier's completion we'd never have done it--and even so it's been a tremendous task."