But in a moment a guard came for Joe and took him to where the Chief and Haney and Mike waited by the still incompletely-pulled-away crates. They had some new ideas about the job on hand that were better than the original ones in some details. All four of them set to work to make a careful survey of damage--of parts that would have to be replaced and of those that needed to be repaired. The discoveries they made would have appalled Joe earlier. Now he merely made notes of parts necessary to be replaced by new ones that could be had within the repair time for rebalancing the rotors. "This is sure a mess," said Haney mournfully, as they worked. "It's two days just getting things cleaned up!" The Chief eyed the rotors. There were two of them, great four-foot disks with extraordinary short and stubby shafts that were brought to beautifully polished conical ends to fit in the bearings. The bearings were hollowed to fit the shaft ends, but they were intricately scored to form oil channels. In operation, a very special silicone oil would be pumped into the bearings under high pressure. Distributed by the channels, the oil would form a film that by its pressure would hold the cone end of the bearing away from actual contact with the metal. The rotors, in fact, would be floated in oil just as the high-speed centrifuge the Chief had mentioned had floated on compressed air. But they had to be perfectly balanced, because any imbalance would make the shaft pierce the oil film and touch the metal of the bearing--and when a shaft is turning at 40,000 r.p.m. it is not good for it to touch anything. Shaft and bearing would burn white-hot in fractions of a second and there would be several devils to pay. "We've got to spin it in a lathe," said the Chief profoundly, "to hold the chucks. The chucks have got to be these same bearings, because nothing else will stand the speed. And we got to cut out the bed plate of any lathe we find. Hm. We got to do our spinning with the shaft lined up with the earth's axis, too." Mike nodded wisely, and Joe knew he'd pointed that out. It was true enough. A high-speed gyro could only be run for minutes in one single direction if its mount were fixed. If a precisely mounted gyro had its shaft pointed at the sun, for example, while it ran, its axis would try to follow the sun. It would try not to turn with the earth, and it would wreck itself. They had to use the cone bearings, but in order to protect the fine channellings for oil they'd have to use cone-shaped shims at the beginning while running at low speed. The cone ends of the shaft would need new machining to line them up. The bearings had to be fixed, yet flexible. The---- They had used many paper napkins the night before, merely envisioning these details. New problems turned up as the apparatus itself was being uncovered and cleaned.