"I felt rather hurt at his retort and a certain coolness sprang up between us. The summer holidays came and I went away without bidding him good-by. But returning for the new semester, my first act was to hurry to the laboratory. He greeted me as if there had never been any difference between us. "'Come,' he cried; 'you must see what I have accomplished. It is marvelous, marvelous.' "In his workshop stood a mechanism perhaps three feet square and four feet high. It was made of polished steel and looked not unlike an Edison music box. "'You are the first I have shown it to,' he said excitedly. 'Here, look into this.' "Stooping over the top of the box I peered into the eye-piece indicated. It was so fashioned that it fitted the contour of the face snugly. "'Now hold steady,' warned the Professor. 'This machine makes quite a noise, but it won't harm you at all.' "I sensed that he was fingering and arranging dials and levers on the side of the contrivance. Suddenly an engine in the box began to throb with a steady rhythm. This gradually increased in tempo until the vibration of it shook the room. "'Don't move,' shouted the Professor. "At first I could see nothing. Everything was intensely dark. Then the darkness began to clarify. Or rather I should say it seemed as if the darkness increased to such a pitch that it became--oh, I can't describe it! But of a sudden I had the sensation of looking into the utter bleakness and desolation of interstellar space. Coldness, emptiness--that was the feeling. And in this coldness and emptiness flamed a distant sun, around which twelve darker bodies the size of peas revolved. They revolved in various ellipses. And far off--millions of light years away (the thought came to me involuntarily at the time)--I could glimpse infinitesimal specks of light, a myriad of them. With a cry I jerked back my head. "'That,' shouted the Professor in my ear, 'was an atomic universe.' "It never entered my head to doubt him. The realness, the vividness, the overwhelming loneliness and vastness of the sight I had seen--yes, and the suggestion of cosmic grandeur and aloofness that was conveyed--banished any other feeling but that of belief. "'Inside that box,' said Professor Reubens quietly, 'and directly underneath the special crystal-ray medium I have perfected, is a piece of matter no larger than a pin-head. But viewed through the magnifying medium of the crystal-ray that insignificant piece of matter becomes as vast and as empty as all space, and in that space you saw--an atomic system.' "An atomic system! Imagine my emotions. The tremendousness of the assertion took away my breath. I could only seize the Professor's hand and hold to it tightly. "'Softly, my boy, softly,' he said, smiling at my emotion. 'What you have seen is but the least part of the invention. There is more to it than that.' "'More?'