Professor Eddinger's tired eyes crinkled to a smile. Enthusiasm like this was rare among his youngsters. But Avery--with the face of a poet, a dreamer's eyes and the mind of a scientist--good boy, Avery!--a long time since he had seen him--had him in his own laboratory for two years.... "What's this all about?" he asked. "No--no!" said a voice; "I can't tell you--it is too big--greater than the induction motor--greater than the electric light--it is the greatest thing in the world. The taxi should be there now--you must come--" A knock at the office door where a voice said, "Car for Professor Eddinger," confirmed the excited words. "I'll come," said the Professor, "right away." * * * * * He pondered, as the car whirled him across the city, on what this greatest thing in the world might be. And he hoped with gentle skepticism that the enthusiasm was warranted. A young man opened the car door as they stopped. His face was flushed, Eddinger noted, hair pushed back in disarray, his shirt torn open at the throat. "Wait here," he told the driver and took the Professor by the arm to hurry him into a dilapidated building. "Not much of a laboratory," he said, "but we'll have better, you and I; we'll have better--" The room seemed bare with its meager equipment, but it was neat, as became the best student of Professor Eddinger. Rows of reagent bottles stood on the shelves, but the tables were a litter of misplaced instruments and broken glassware where trembling hands had fumbled in heedless excitement. "Glad to see you again, Avery." The gentle voice of Professor Eddinger had lost its tired tone. "It's been two years you've been working, I judge. Now what is this great discovery, boy? What have you found?" The younger man, in whose face the color came and went, and whose eyes were shining from dark hollows that marked long days and sleepless nights, still clung to the other's arm. "It's real," he said; "it's great! It means fortune and fame, and you're in on that, Professor. The old master," he said and clapped a hand affectionately upon a thin shoulder; "I owe it all to you. And now I have--I have learned.... No, you shall see for yourself. Wait--" * * * * * He crossed quickly to a table. On it was an apparatus; the eyes of the older man widened as he saw it. It was intricate--a maze of tubing. There was a glass bulb above--the generator of a cathode ray, obviously--and electro-magnets below and on each side. Beneath was a crude sphere of heavy lead--a retort, it might be--and from this there passed two massive, insulated cables. The understanding eyes of the Professor followed them, one to a terminal on a great insulating block upon the floor, the other to a similarly protected terminal of carbon some feet above it in the air.