They sat and stared at their amazing uncle. There was a hush upon the entire universe; there was marvel, mystery, but at first there was also muddle. They waited, holding their breath with difficulty. Some one, it seemed, must either explode or--or something else, they knew not exactly what. It would hardly have surprised them if Judy had suddenly flown through the air, Tim vanished down a hole, or Maria gleamed at them from the inside of a quivering bubble of soap. There was this kind of intoxicating feeling, delicious and intense. Even To-morrow might _not_ be Sunday after all: it felt strange and wonderful enough for that! The possibility that _Some Day_ was coming--was close at hand--had in some mysterious way become a probability. It was clear at last why Uncle Felix had been so heavy and preoccupied. "You see what's happened?" he continued after the long pause. "You see what it all means--this strange stopping of the clock--at Dawn?" They admitted nothing; the least mistake on their part might prevent, might spoil or cripple it. The depth and softness of his tone warned them. They stared and waited. He gathered them closer to him with both arms. Even Maria wriggled slightly nearer--an inch or so. "It means," he said in still lower tones, "the calendar,"--then stopped abruptly to examine the effect upon them. Now, ordinarily, they knew quite well what a calendar was; but this new, strange emphasis he put upon it robbed the word suddenly of all its original meaning. Their minds went questioning at once: "What _is_ a calendar?" asked Judy carefully--"exactly?" she added, to make her meaning absolutely clear. It sounded almost like a nonsense word. "Exactly," he repeated cautiously, yet with some great emotion working in him, "what is a calendar? That's the whole question. I'll try and tell you what a calendar is." He drew a deeper breath, a great effort being evidently needed. "A calendar," he went on, while the word sounded less real each time it was uttered, "is an invention of clever, scientific men to note the days as they pass; it records the passing days. It's a plan to measure Time. It's made of paper and has the date and the name of the day stamped in ink on separate sheets. When a day has passed you tear off a sheet. That day is done with--gone. There are three hundred and sixty-five of these separate sheets in a year. It's just an invention of scientific men to measure the passing of--Time, you see?" They said they saw. "Another invention," he resumed, his face betraying more and more emotion, "is a clock. A clock is just a mechanical invention that ticks off the movements of the sun into seconds and minutes and hours. Both clocks and calendars, therefore, are mere measuring tricks. Time goes on, or does not go on, just the same, whether you possess these inventions or whether you do not possess them. Both clocks and calendars go at the same rate whether Time goes fast or slow. See?"