"Now I am really interested," admitted Channing. "Oil switches in a spaceship are a definite drawback." "I know. So--here we are." "What's the rest of this stuff?" asked Channing, laying a hand on the glassware. "Be careful!" said Farrell in concern. "That's hot stuff." "Oh?" "In order to get some real voltages and currents to break without running the main Station bus through here, I cooked this stuff up. The plate-grilleworks in the large tubes exhibit a capacity between them of about one microfarad. Empty, that is, or I should say precisely point nine eight microfarads in vacuuo. The fluid is of my own devising, concocted for the occasion, and has a dielectric constant of thirteen times ten to the sixth power. It--" "Great Howling Rockets!" exploded Channing. "That makes the overall capacity equal to thirteen _farads_!" "Just about. Well, I have the condenser charged to three kilovolts, and then I discharge it through this switch made of the non-arcing alloy. Watch! No, Don, from back here, please, behind this safety glass." Channing made some discomforting calculations about thirteen farads at three thousand volts charge and decided that there was something definitely unlucky about the number thirteen. "The switch, now," continued Farrell, as though thirteen farads was just a mere drop in the bucket, "is opened four milliseconds after it is closed. The time-constant of the discharging resistance is such that the voltage is point eight three, of its peak three thousand volts, giving a good check of the alloy." "I should think so," groused Channing. "Eighty-three percent of three thousand volts is just shy of twenty-five hundred volts. The current of discharge passing through a circuit that will drop the charge in a thirteen farad condenser eighty-three percent in four milliseconds will be something fierce, believe me." "That is why I use the heavy busbars from the condenser bank through the switch." "I get it. Go ahead, Wes. I want to see this non-arcing switch of yours perform." Farrell checked the meters, and then said "Now!" and punched the switch at his side. Across the room a solenoid drove the special alloy bar between two clamps of similar metal. Almost immediately, four thousandths of a second later, to be exact, the solenoid reacted automatically and the no-arc alloy was withdrawn. A minute spark flashed briefly between the contacts. "And that is that," said Channing, slightly dazed by the magnitude of it all, and the utter simplicity of the effects. "But look, Wes, may I ask you a favor? Please discharge that infernal machine and drain that electrolyte out. Then make the thing up in a tool-steel case and seal it. Also hang on busbars right at the plates themselves, and slap a peak-voltage fuse across the terminals. One that will close at anything above three thousand volts. Follow me?" "I think so. But that is not the main point of interest--"