"All x." Breckenridge studied his triplex chronometer intently, then unplugged and glanced around the control room, in various parts of which half a dozen assistants were loafing at their stations. "Control and power check-out--Hipe!" he barked. "Driving converters and projectors!" The first assistant scanned his meters narrowly as he swung a multi-point switch in a flashing arc. "Converter efficiency 100, projector reactivity 100; on each of numbers one to forty-five inclusive. All x." "Dirigible projectors!" * * * * * Two more gleaming switches leaped from point to point. "Converter efficiency 100, projector reactivity 100, dirigibility 100, on each of numbers one to thirty-two, inclusive, of upper band; and numbers one to thirty-two, inclusive, of lower band. All x." "Gyroscopes!" "35,000. Drivers in equilibrium at ten degrees plus. All x." "Upper lights and lookout plates!" The second assistant was galvanized into activity, and upon a screen before him there appeared a view as though he were looking directly upward from the prow of the great vessel. The air above them was full of aircraft of all shapes and sizes, and occasionally the image of one of that flying horde flared into violet splendor upon the screen as it was caught in the mighty, roving beam of one of the twelve ultra-light projectors under test. "Upper lights and lookout plates--all x," the second assistant reported, and other assistants came to attention as the check-out went on. "Lower lights and lookout plates!" "All x," was the report, after each of the twelve ultra-lights of the stern had swung around in its supporting brackets, illuminating every recess of the dark depths of the bottom well of the berth and throwing the picture upon another screen in lurid violet relief. "Lateral and vertical detectors!" "Laterals XP2710--all x. Verticals AJ4290--all x." "Receptors!" "15,270 kilofranks--all x." "Accumulators!" "700,000 kilofrank-hours--all x." Having thus checked and tested every function of his department, Breckenridge plugged into "Captain," and when the green light went on: "Chief pilot check-out--all x," he reported briefly. "All x," acknowledged the speaker, and the chief pilot unplugged. Fifteen minutes remained, during which time one department head after another would report to the captain of the liner that everything in his charge was ready for the stupendous flight. "All x, Steve?" Breckenridge turned to the computer. "How do you check acceleration and power with the observatory?" "Not so good, old bean," the younger man frowned in thought. "They figure like astronomers, not navigators. They've made no allowances for anything, not even the reversal--and I figure four thousands for that and for minor detours. Then there's check station errors...." "Check-station errors! Why, they're always right--that's what they're for!"