"So?"
"So, that’s a way of looking at the world that scholars use. You make an observation: some animals eat plants and some do not. You propose an idea, a pre-fact, shall we say, a statement that might be a fact or might not: I can eat plants, too. Then you perform a test: you eat a plant. You note the results: you get sick. And you draw a conclusion: my pre-fact was in error; it is not a true fact. I cannot eat plants."
"Afsan, you credit youngsters with too much thought. Observations! Pre-facts! What nonsense. I just stuck some leaves in my mouth and swallowed. I’d done the same thing with dirt, with pieces of wood, and so on. It wasn’t some grand test. It was just the silliness of childhood."
"Good Captain, forgive me, but I don’t think so. I believe you did go through every one of the steps I described, but so quickly, so seamlessly, that you might not have been aware of it."
Keenir’s tone was hard. "You are presuming a great deal, eggling."
"I meant no presumption, but surely…" Afsan thought better of what he was about to say, stopped, swallowed, and tried again. "Scholars have found that there is value in this method of inquiry."
"Well, if it got you to stop eating plants, I suppose there is." Keenir clicked his teeth in self-satisfied amusement.
"May I tell you of some other observations I’ve made?" asked Afsan.
"Lad, I’ve got chores to perform." He looked pointedly down his muzzle. "I suspect you do, too."
"I will be brief, sir. I promise."
"By the prophet’s claws, lad, I don’t know why people put up with so much from you. Somehow, even Saleed takes you seriously. And you’ve got the ear of the crown prince." Keenir was silent for a moment, and Afsan thought about what he’d said. Saleed takes me seriously? Ha! At last, the old captain spoke again. "Very well, Afsan. But I’ll hold you to your promise of brevity. There’s only a few days until we set sail again, after all."
Afsan decided that it would be politic to click his teeth in appreciation of Keenir’s joke. Then: "I’ve been making observations with the far-seer and with my own unaided eyes. I’ve seen that the Face of God rose into the sky as we moved east, until, as now, it’s at its highest point. It can rise no farther into the sky, for it sits directly overhead. I’ve seen, too, that it goes through phases, just as the moons do, and just — as I’ve learned by looking upon them through the far-seer — as some of the planets do."
Keenir raised his muzzle, exposing the underside of his neck, a gesture of mild concession. "I’ve used the far-seer myself to have a peek at the planets. I was mildly intrigued by that. Told Saleed about it, but he dismissed what I’d seen."
"Indeed?" said Afsan, grateful that Keenir had been curious enough to make some observations himself. "I think it’s significant."
"Well," said Keenir, his voice a low rumble, "I did wonder how what previously had seemed only a point of light could show phases."
"I’m sure you saw through the far-seer that some of the planets show visible disks, Captain. They appear as points of light only because they are so far away."
"Far away? The planets are no more distant than the stars, no farther than the moons. All the objects in the sky move across the same celestial sphere, just sliding along it at different rates."
"Uh, no, sir, they don’t. I’ve made models and I’ve done figuring on writing sheets." Afsan paused, took a deep breath. "Captain, my observations lead me to propose a pre-fact: the world is spherical, just as the moons are spherical, just as the sun is spherical, just as the Face of God is spherical."
"The world spherical? How can that be?"
"Well, sir, surely you have stood on the docks at Capital City and seen the tops of masts of ships appear at the horizon before the rest of the ship does." Afsan held up his right fist and moved a finger of his left hand over its curving surface. "That’s the ship coming over the curve of the world."
"Oh, don’t be silly, boy. There are waves in the great River — you can feel them tossing this boat right now. Well, some waves are so big and so gentle that ships move over the crests and troughs without us being aware of it. That’s what causes the effect you’ve described."
Can he really believe that? thought Afsan. Does he accept everything he reads so easily, without question? "Sir, there’s a lot of evidence to make me believe that the world is round. It must be! A sphere, a ball, whatever you want to call it." Keenir’s tail was swishing in disbelief, but Afsan pressed on. "Further, this round world is mostly covered with water. We, here in the Dasheter, are sailing not on a River but rather on the watery surface of our spherical world, as if almost the entire surface was a — a — super-lake."
"You’re saying we’re a ball of water?"
"No, I’m sure the rocky floor we see beneath the coastal waters continues all the way around, even here, out where it’s far too deep for us to see the bottom. No, our world is a sphere of rock, but mostly covered by water."
"Like a raloodoo?"
"Like a what?"
"Eggling, they don’t feed you apprentices well enough at the palace. A raloodoo is a delicacy from Chu’toolar province. You take the eye of a shovelmouth, remove it carefully, and dip it in the sugary sap of a mladaja tree. The sugar hardens into a crunchy coating over the surface of the eyeball."
"Yes, then, you’re right. Except that the eyeball is the rocky sphere of our world, and the thin coat of sugar is the water that covers almost all of the surface."
"All right," said Keenir. "I don’t accept this for an instant, you understand, but at least I can picture what you’re talking about."
Afsan nodded concession, then went on. "Now, then, how big is our world?"
"Surely that’s impossible to tell."
"No, Captain. Forgive me, but we have all the information we need to make the calculation. As you remarked earlier, we are sitting still beneath the Face of God. If we don’t move the ship, the Face doesn’t appear to move at all. It is only the movement of this vessel that causes the Face to apparently rise or set. Therefore, we can use the speed of the Dasheter as our measuring stick to calculate how far we’ve sailed around the world. You yourself told us it was a four-thousand-kilopace journey from the point at which the Face of God was just below the horizon to when it was just above."
"Aye, I did say that. Thirty-two days sailing."
"Well, if it takes thirty-two days for the Face to rise by its own height, we must in those thirty-two days have sailed one-eighth of the circumference of the world."
"How do you figure that?"
"Well, the Face covers a quarter of the sky, and the sky is a hemisphere — a half circle."
"Oh, right. Of course. If the Face covers a quarter of a half, it therefore covers an eighth of the whole. Yes, I see that."
"And the angles subtended by the Face…"
"I said I saw it, eggling. I’m a mariner; I know all about measuring sky angles for navigation."
Afsan cringed, bowed quickly, then pressed on. "Now, it took thirty-two days to sail the four thousand kilopaces needed for the Face to rise by its own height. Thus, in thirty-two days we sailed one-eighth of the way around the world. Therefore the circumference of the world is eight times four thousand kilopaces, or thirty-two thousand kilopaces."
Keenir nodded dubiously.
Afsan continued. "And it took us 113 days to get from Capital City to the point at which we first saw the leading edge of the Face on the horizon." Afsan blinked once, doing the math. "That’s 3.53 times as long as it took to sail one-eighth of the world’s circumference. So, in that part of the voyage, we must have sailed 3.53 times one-eighth of the way around the world." Afsan blinked again. "That’s just under halfway around; 44.125 percent, to be precise." He clicked his teeth lightly. "Of course, that’s too many places of accuracy."