Don grunted. He did not care to be addressed by title when someone who disliked him did it. His friends did not, and Kingman's use of the title made it an insult. "Look," said Kingman, "what do you want to use those blocks for?" "We've got a job of checking dimensions." "Nothing more? Do you need the metal for electrical reasons?" "No," said Don. "What have you in mind?" "Our toolshop is nicely equipped to grind glass gauges. We can do that better than making Jo-blocks. Can you use glass ones?" "Hang on a minute." Channing turned to Walt. "Kingman says his outfit uses glass gauges. Any reason why we can't?" "See no reason why not. I've heard of using glass gauges, and they've got some good reasons, too. Tell him to go ahead." "Kingman? How soon can we get glass ones?" "Horman, how soon on the glass blocks?" "Two dozen? About a week." "We'll have your blocks on the way within four days, Channing. Four days minimum, plus whatever wait is necessary to get 'em aboard a spacer." "We'll check from this end on schedules. We need the blocks, and if the wait is too long, we'll send the _Relay Girl_ in for 'em." Don hung up and then said: "Glass ones might be a good idea. We can check the transmission characteristics optically. I think we can check more, quickly, than by running analysis on steel." "Plus the fact that you can get the blocks back after test," grinned Walt. "Once you tear into a steel block to check its insides, you've lost your sample. I don't know any other way to check the homogeneity than by optical tests." "O.K. Well, four days for glass will do better than a couple of months on steel blocks." "Right. Now let's look up Wes and see what he's come up with." * * * * * They found Farrell in one of the blister laboratories, working on a small edition of the power-transmission tubes. He was not dressed in spacesuit, and so they entered the blister and watched him work. "Have a little trouble getting the focus to stay sharp through the trace," complained Wes. "I can get focus of atomic proportions--the circle of confusion is about the size of the atom nucleus, I mean--at the axis of the tube. But the deflection of the cone of energy produces aberration, which causes coma at the edges. The corners of an area look fierce." "I wonder if mechanical scanning wouldn't work better." "Undoubtedly. You don't hope to send life, do you?" "It would be nice--but no more fantastic than this thing is now. What's your opinion?" Wes loosened a set screw on the main tube anode and set the anode forward a barely perceptible distance. He checked it with a vernier rule and tightened the screw. He made other adjustments on the works of the tube itself, and then motioned outside. They left the blister, Wes closed the airtight, and cracked the valve that let the air out of the blister. He snapped the switch on the outside panel and then leaned back in his chair while the cathode heated.