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 air-tight, 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.
"With electrical scanning, you'll have curvature of field with this gadget. That isn't too bad, I suppose, because the restorer will have the same curvature. But you're going to scan three ways, which means correction for the linear distance from the tube as well as the other side deflections and their aberrations. Now if we could scan the gadget mechanically, we'd have absolute flatness of field, perfect focus, and so forth."
Walt grinned. "Thinking of television again? Look, bright fellows, how do you move an assembly of mechanical parts in quanta of one atomic diameter? They've been looking for that kind of a gadget for centuries. Dr. Rowland and his gratings would turn over in their graves with a contrivance that could rule lines one atom apart."
"On what?" asked Don.
"If it would rule one atom lines, brother, you could put a million lines per inch on anything rulable with perfection, ease, eclat, and savoir faire. You follow my argument? Or would you rather take up this slip of my tongue and make something out of it?"