"That would do it," said Channing thoughtfully. "But I don't think I'd know how to modulate a Van Der Graf. A betatron would be the thing. You can modulate that, sort of, by keying the input. She'd give out with hundred-and-fifty-cycle stuff. How much of a trick is it to clear the observation dome from the top?"
"What do you intend to do?"
"Well, we've got a long, hollow tube in this ship. Knock out the faceted dome above, and we can rig us up a huge electron gun. We'll turn the ship to point at the station and beam 'em with a bouquet of electrons."
"How're you going to do that?"
"Not too tough, I don't think. Down here," and Channing began to trace on the tablecloth, "we'll put in a hot cathode. About this level we'll hang the first anode, and at this level we'll put the second anode. Here'll be an acceleration electrode, and up near the top we'll put a series of focussing anodes. We'll tap in to the driver-tube supply and take off voltage to suit us. Might use a tube at that, but the conversion to make an honest electron gun out of it would disrupt our power, and then it would be impossible to re-make a driver out of it without recourse to a machine shop."
"How are you going to make electrodes?"
"We'll use the annular gratings that run around the central well at each level," said Channing. "We'll have a crew of men cut 'em free and insulate the resulting rings with something. Got anything?"
"There is a shipment of methyl-methacrylate rods for the Venus Power Company in hold 17," said the cargo master.
"Fine," said Channing. "What size?"
"Three inches by six feet."