As soon as the connections were completed, the robot backed swiftly out of the room, and Arcot turned on the magnet and the ray projector. Instantly, there was a sharp deflection of the kilovoltmeter.
"I haven't yet closed the switch leading into the coil," he explained, "so there's no current." The ammeter needle hadn't moved.
Despite the fact that the voltmeter seemed to be shorted out by the relux plate, the needle pointed steadily at twenty-two. Arcot changed the current through the magnet, and the reading dropped to twenty.
The rays had been on at very low power, the air only slightly ionized, but as Arcot turned a rheostat, the intensity increased, and the air in the path of the beam shone with an intense blue. The relux plate, subject now to eddy currents, since there was no other path for the energy to take, began to heat up rapidly.
"I'm going to close the switch into the coil now," said Arcot. "Watch the meters."
A relay snapped, and instantly the ammeter jumped to read 4500 amperes. The voltmeter gave a slight kick, then remained steady. The heavy coronium spring grew warm and began to glow dully, while the ammeter dropped slightly because of the increased resistance. The relux plate cooled slightly, and the voltmeter remained steady.
"The coil you see is storing the energy that is flowing into it," Arcot explained. "Notice that the coronium resistor is increasing its resistance, but otherwise there is little increase in the back E.M.F. The energy is coming from the rays which strike the polarized relux plate to give the current."
He paused a moment to make slight adjustments in the controls, then turned his attention back to the screen.
The kilovoltmeter still read twenty.
"Forty-five hundred amperes at twenty thousand volts," the elder Arcot said softly. "Where is it going?"