But the four of them gazed at it--now that it worked--with a sudden passionate satisfaction. Joe moved a control, and the axis of the device moved smoothly to a new place and stayed there. He moved the control again, and it moved to another position and stayed there. And to another and another and another. Then the Chief took Joe's place, and under his hand the seemingly static disks--which were actually spinning at forty thousand revolutions per minute--turned obediently and without any appearance of the spectacular. Then Haney worked the controls. And Mike put the device through its paces. Mike left the gyros spinning so that the main axis pointed at the sun, invisible beyond the Shed's roof. And then all four of them watched. It took minutes for this last small test to show its results. But visibly and inexorably the pilot gyros followed the unseen sun, and they would have resisted with a force of very many tons any attempt to move them aside by so little as one-tenth of a second of arc, which would mean something like one three-hundred-thousandth of a right angle. And these pilot gyros would control the main gyros with just this precision, and after the Platform was out in space could hold the Platform itself with the steadiness needed for astronomical observation past achievement from the surface of the Earth. The pilot gyros, in a word, were ready for installation. Joe and Haney and the Chief and Mike were not beautiful to look at. They were begrimed from head to toe, and their eyes were bloodshot, and they were exhausted to the point where they did not even notice any longer that they were weary. And their mental processes were not at all normal, so that they were quarrelsome and arbitrary and arrogant to the men with the flat-bed trailer who came almost reverently to move their work. They went jealously with the thing they had rebuilt, and they were rude to engineers and construction workers and supervisors, and they shouted angrily at each other as it was hoisted up a shaft that had been left in the Platform for its entrance, and they were very far from tactful as they watched with hot, anxious eyes as it was bolted into place. It would be welded later, but first it was tried out. And it moved the main gyros! They weighed many times what the pilot gyros did, but even when they were spinning the pilot gyros stirred them. Of course the main-gyro linkage to the fabric of the Shed had to be broken for this test, or the gyros would have twisted the giant upon its support and all the scaffolding around it would have been broken and the men on it killed. But the gyros worked! They visibly and unquestionably worked! They controlled the gigantic wheels that would steer the Platform in its take-off, and later would swing it to receive the cargo rockets coming up from Earth. The pilot instrument worked! There was no vibration. In its steering apparatus the Platform was ready for space!