"That is something I have had no means of determining. It was rather a curious thing; when I left that letter for you," the Chemist turned to the Doctor--"it never occurred to me that although I had told you to start down here on a certain day, I would be quite at a loss to calculate when that day had arrived. It was my estimation after my first trip here that time in this world passed at a rate about two and two-fifth times faster than it does in your world. That is as near as I ever came to it. We can calculate it more closely now, since we have only the interval of your journey down as an indeterminate quantity." "How near right did you hit it? When did you expect us?" asked the Doctor. "About thirty days ago; I have been waiting since then. I sent nearly a hundred men through the tunnels into the forest to guide you in." "You taught them pretty good English," said the Very Young Man. "They were tickled to death that they knew it, too," he added with a reminiscent grin. "You say about thirty days; how do you measure time down here?" asked the Big Business Man. "I call a day, one complete cycle of sleeping and eating," the Chemist replied. "I suppose that is the best translation of the Oroid word; we have a word that means about the same thing." "How long is a day?" inquired the Very Young Man. "It seems in the living about the same as your twenty-four hours; it occupies probably about the interval of time of ten hours in your world. "You see," the Chemist went on, "we ordinarily eat twice between each time of sleep--once after rising--and once a few hours before bedtime. Workers at severe muscular labor sometimes eat a light meal in between, but the custom is not general. Time is generally spoken of as so many meals, rather than days." "But what is the arbitrary standard?" asked the Doctor. "Do you have an equivalent for weeks, or months or years?" "Yes," answered the Chemist, "based on astronomy the same as in your world. But I would rather not explain that now. I want to take you, later to-day, to see Lylda's father. You will like him. He is--well, what we might call a scientist. He talks English fairly well. We can discuss astronomy with him; you will find him very interesting." "How can you tell time?" the Very Young Man wanted to know. "There is no sun to go by. You have no clocks, have you?" "There is one downstairs," answered the Chemist, "but you didn't notice it. Lylda's father has a very fine one; he will show it to you." "It seems to me," began the Doctor thoughtfully after a pause, reverting to their previous topic, "that without sickness, under such ideal living conditions as you say exist here, in a very short time this world would be over-populated."