The Chemist smiled. "You are too modest, my father. But I will help you out, if you insist." He turned to the others, who were gathered around him, looking at the clock.
"Our measurement of our time here," he began, "like yours, is based on——"
"Excuse me," interrupted the Very Young Man. "I just want to know first what time it is now?"
"It is in the fourth eclipse," said the Chemist with a twinkle.
The Very Young Man was too surprised by this unexpected answer to question further, and the Chemist went on.
"We measure time by the astronomical movements, just as you do in your world. One of the larger stars has a satellite which revolves around it with extreme rapidity. Here at Arite, this satellite passes nearly always directly behind its controlling star. In other words, it is eclipsed. Ten of these eclipses measure the passage of our day. We rise generally at the first eclipse or about that time. It is now the fourth eclipse; you would call it late afternoon. Do you see?"
"How is the time gauged here?" asked the Big Business Man, indicating the clock.
The instrument stood upon a low stone pedestal. It consisted of a transparent cylinder about twelve inches in diameter and some four feet high, surmounted by a large circular bowl. The cylinder was separated from the bowl by a broad disc of porous stone; a similar stone section divided the cylinder horizontally into halves. From the bowl a fluid was dropping in a tiny stream through the top stone segment into the upper compartment, which was now about half full. This in turn filtered through the second stone into the lower compartment. This lower section was marked in front with a large number of fine horizontal lines, an equal distance apart, but of unequal length. In it the fluid stood now just above one of the longer lines-the fourth from the bottom. On the top of this fluid floated a circular disc almost the size of the inside diameter of the cylinder.
The Chemist explained. "It really is very much like the old hour-glass we used to have in your world. This filters liquid instead of sand. You will notice the water filters twice." He indicated the two compartments. "That is because it is necessary to have a liquid that is absolutely pure in order that the rate at which it filters through this other stone may remain constant. The clock is carefully tested, so that for each eclipse the water will rise in this lower part of the cylinder, just the distance from here to here."
The Chemist put his fingers on two of the longer marks.