While yet the three listeners and watchers bent their heads toward the panel in the wall, a strange thing occurred. The silver frostiness of the screen became violently agitated with what looked like tiny sparks darting in and about each other like miniature solar systems. Shanghai faded from the picture. All that remained visible now was the jumbled mass of needle-pointed sparks of luminosity. "Careful," warned Carruthers. "Slow up the speed of your reflector, Karl. There, that's better. Watch the meter reading. I'm going to step up the power of the dimensional tubes. Steady!" * * * * * From an invisible reproducer came a sharp, metallic crackling like machine-gun bullets rattling on a tin roof. The sparks on the screen became violently agitated, pushing around in erratic circles and ellipses. They glowed constantly in shades of bright green through the blues into the deep violets of the color scale. "What do you read?" asked Carruthers. "Point seven six nine," answered Karl. "Shift it back towards the blue, about two points lower on the scale." Danzig twisted two dials at the same time with minute exactness. "Point seven six eleven," he intoned. "Hold it," ordered Carruthers. "Blue should predominate." He turned his eyes on the dancing sparks on the screen. They glowed now a deep indigo blue. "Lock your dials against accidental turning. We're tuned to the vanishing point." Danzig rose to his feet. "What will we use?" Carruthers looked hastily around the room. "Most anything will do." His eyes rested on a glass test tube. Quickly he rose to his feet and removed it from the wall rack. Then bending over the glass railing that enclosed the mysterious square he placed it on the floor. He turned now to the girl. "Quiet, now, Nanette, and don't under any condition leave the chair. The path of the ray should pass within two feet of you, having a wide margin of safety. All right, Karl. Set the dials of the inverse dimensional tubes at point seven six eleven, and switch the power to the Roentgen tube." Through the dimly lighted laboratory came a spurt of bluish flame that twisted and squirmed with slow undulations around the cathode electrode. "Fine," enthused Carruthers, "The cathode emanations coincide exactly with the interference chart. Watch your meter gauges, Karl, while I switch to the atomic ray." * * * * * His fingers closed over a switch. The indigo points of flame bathing the electrode gathered themselves into a ring and began to revolve around an invisible nucleus located near the electrode. Carruthers studied the revolving flame for a moment, then switched off the television machine. It was no longer needed. Carefully, for the atomic ray was still a mysterious force to Carruthers, he opened a small door in the panel and drew out the focusing machine. It was shaped very much like a camera except that the lens protruded several inches beyond the machine proper.