"Have the Cow display barometric readings for each section of the rim and for each compartment in the central hub," he said briefly to Bessie; and to the astronomer, "Dr. Kimball, take that side seat at the computer console and check our progress on this orbital deviation," and he gestured at the display on his screen. Perk moved to the post with only a nod. * * * * * The barometric displays held constant, with only fractional deviations that might have been imposed by the spin of the big wheel, or error in the instruments themselves. Balanced against temperature readings, they worked out to possible fractions of gain or loss so small as to be insignificant, indicating only the inaccuracies of measurement that inevitably occur in comparing the readings of a number of instruments. The captain had hardly digested the readings displayed by the computer when Perk looked up with a puzzled frown. "The computer records a continuous acceleration over the past eleven hours and forty-three minutes," he said, "and attributes it," he looked even more puzzled, "to a magneto-ionic effect?" There was a definite question in his voice. "It's only about six hundred forty pounds," he added. "It must be an external effect caused by the flare." "Please investigate the effect as thoroughly as possible," the captain told Perk, then dictated a message to the com officer. "'To U.N. Headquarters, Earth, from Captain Naylor Andersen, commanding Space Lab One. Original assumption that disaster was attributable to meteoric impact on Project Hot Rod appears mistaken. Investigation indicates we are under acceleration from an external magneto-ionic effect which is exerting about--'" he called to Perk. "Did you say six hundred forty pounds?" The astronomer nodded, and the captain continued, "'Which is exerting about six hundred forty pound pressure against this satellite. We are now working out corrective measures and will inform you immediately they are prepared. If your observatories can give us any advice, please message at once. End.'" Then the captain depressed his intercom switch to the morgue. "Dr. Chi. Please report to the bridge. Repeat. Dr. Chi Tung. Please report to the bridge at once." His own intercom hummed, and a voice came on. "Dr. Chi Tung is not in the morgue. He left with Mr. Blackhawk some time ago." The captain frowned, but pushed the engineering room intercom. "Is Dr. Chi with you, Mr. Blackhawk?" he asked, and when Mike's voice answered, "Yes, sir," he said, "Will you both report to the bridge at once, please?" When the two arrived, only a little tardily, on the bridge, the captain addressed Ishie. "You heard of the disaster last night?" The physicist nodded. "We assumed then," the captain told him, "that a meteor had caused the disturbance. That it had gone through the balloon making a hole through which the balloon's nitrogen was escaping, making a jet action and accelerating the ship.