Omar Khayyam - a life (13 page)

The House of the Stars by the river of Nisapur.

Khwaja Mai'mun ibn Najib Al-Wasitt sat with his hands tucked in his sleeves in the audience room of the tower. Beside him sat Muzafar al Isfizari, from the observatory of Urghand. And along the wall sat their six assistants who had labored with them for a year.

On low tables before them lay sheets of paper with columns of figures, the fruit of their labor. In his dry voice Khwaja Mai'mun was explaining what they had accomplished, while he wrestled with inward misgivings. Certainly, the sunburned young King's astronomer who had just returned from the west and who lay outstretched on cushions appeared to be drunk. At least his eyes wandered and he hummed gently to himself a song.

Moreover, behind Omar reclined a tattered jester and a dour graybeard in a black skullcap. Khwaja Mai'mun felt that he was losing dignity before his fellow mathematicians. A jester among scientists!

So he broke off his ceremonious report and observed with cold disapproval, "The sunrise of the vernal equinox failed to meet our established time by three hours and nine minutes."

"Three hours," responded Omar, "and nine minutes."

Mai'mun lowered his eyes. Secretly, he had hoped to strike so close to the sun's time in Omar's absence that credit for the calculation would be given him.

"Take a hammer," said Omar, "and break up the water clock."

"Nay, Excellency," put in Isfizari who had the observation of the clock in his hands, "it varies no more than seventeen minutes from the sun. Perhaps a little more, but——"

"O God," cried Omar, sitting up, "the clock is as true as that?"

"Inshallah"

"And still, you are out with the sun six hours and eighteen minutes in the full year?"

"It was our fate——"

"Go! Find me boys from the bazzaar to watch the instruments, and fair dancing girls of Isfahan to set down the hours! And ye were masters of mathematics! Oh, get ye gone, and teach school."

The assistants rose and left the chamber with Isfizari, only the aged Mai'mun remaining motionless.

"Master," observed Jafarak timidly, "six hours is little enough. Why, I would doze that long after eating a melon, and never think of it again."

"Then you should be an astronomer." Omar clapped his hands. "Bring wine—the dark wine of Shiraz from the sealed jar."

When the frightened servant had filled his goblet, he drank slowly. It seemed to Mai'mun that a devil had entered the Tentmaker. But he would not leave his place without justifying himself. Akroenos looked on impassively. Omar sighed and took up one of the papers.

"Who made these records?"

'Excellency" said Mai'mun grimly, "I myself verified them. You will find no error."

Omar ran his eye down the figures and took up another sheet at random. Thoughtfully he studied it. "Thou dost swear the calculations are true, and Isfizari swears his clock is unvarying. One of ye hath failed—but which?"

"As for the clock, it serves well enough. Ay, after the first month we knew its variation." Mai'mun lifted his head stubbornly. " 'Tis easy to cry 'Be gone' yet I swear by the Kaaba and by my faith that my hand verified those findings."

"Using the Ptolemaic star tables?"

"Ay, surely."

"Corrected for the latitude of Nisapur? Ptolemy made his observations in Alexandria."

"As I have known. Will your Excellency see for himself? Here is the table of the last month."

Taking up a pen, Omar made a brief calculation and compared it with one of Mai'mun's. Then he frowned. "What is this? The correction is truly made. The stars do not vary, and the clock is known. Yet here one lags six hours behind the other. Hast thou an explanation, O man of Baghdad?"

Slowly Mai'mun shook his head. "It is hidden from me."

"Bring me the Ptolemaic tables."

When the great manuscript was spread before him, Omar took up the first sheet of Mai'mun's records. With bent head he set to work. Akroenos departed to his bed, and Jafarak curled up on a rug to sleep, but the old Mai'mun, watchful as an owl, waited silently. When the flame in the lamp flickered and sank, Mai'mun poured in more oil.

"It cannot be," Omar muttered once, and turned to a new sheet.

When the morning light came through the embrasure, and the lamp dimmed, he reached the end, and Mai'mun stirred expectantly.

"My figures are correct?" he croaked.

For a space Omar studied the first and last pages of the Ptolemy manuscript. "Thy calculations are without error," he murmured. "And so the error of the six hours and eighteen minutes is constant. Thy first entry—there—is like the last, six hours and eighteen minutes away from the sun."

Mai'mun blinked, and assented. It must be so.

"The error is here." Omar laid his hand on the worn manuscript of Ptolemy.

"God forbid! What sayest thou? An error—after all these ages——" Mai'mun choked in his astonishment.

"A constant error, yes."

"But how—such an observer—and no one knew!"

"If we knew how, we could correct it." Omar smiled, his tired eyes thoughtful. "But the great Alexandrine hath been a long time in his grave."

Incredulity struggled with interest in the old man's face, for these star tables had been in use by the scientists of Islam for centuries. He would have expected to see the pillars of the great mosque of Nisapur sway as soon as suspect Ptolemy to be in error.

"Ahai!"
he moaned, as the full significance of their discovery dawned on him. "Then is our work vain. Vain, the labor of Kharesmi, and all the others. Our tables of the fixed stars are false—false." Utterly confounded, he looked about the room. If the floor had risen to stand on end, he would not have felt surprise. But Omar's dark eyes were intent.

"Wait, Mai'mun—wait. The error is slight, it is constant. 'Tis here in the first column, as in the last. These observations were truly made, yet ever false, by so little." He sprang up, to stride across the room and stare out into the blinding sun. "False and true—it cannot be, but it is. If we could tear the veil from the mystery!"

Mai'mun could only shake his head. "With Allah are the keys of the unseen."

"If we could find the key—the key." Omar turned suddenly. "Tell me, are not Ptolemy's longitude and latitude correct?"

"Ay, verily—else we had not followed him these thirty generations."

"Then must he have known the key to his tables of the fixed stars. He could use the tables, but another—not knowing the key—would always fail, as we have failed." He struck his hand upon the open manuscript. "With the key, we can use these tables, Mai'mun—we alone."

"If a hair divide the false from the true, still the false is not the true."

Omar stared at the scientist, and his face relaxed. "Mai'mun, old master, forgive me that I cried out upon thee. Thou hast shown me the key by which the false becomes the true. I see—I see.

"
Y'allah
, no man can see."

" 'Tis such a little key. Why didst thou correct these tables for the latitude of Nisapur?"

"Because——" the astronomer was past wondering—"the fixed stars as seen from Nisapur are seen from another angle at Alexandria, where Ptolemy worked."

"And what," asked Omar gently, "if they were not seen at Alexandria?"

"
Y'allah
. Was not Ptolemy's observatory at Alexandria?"

"Yes, and there is our error."

Mai'mun looked up wearily, without comprehension. "Art mad?" he muttered.

"Nay, for Ptolemy, working at Alexandria, did not make these tables. They were made by another, before his time, at another place. He used them, as we have used them—thinking them his—yet he knew this unknown master of the stars who made the tables. He knew! And so his calculations were true."

Mai'mun's eyes flashed, and then he shrank back. He saw the truth instantly, but it seemed to him as if Omar must have occult power, to discover what had been hidden for nine centuries. Had not Nizam himself said that Omar possessed a strange power?

"It must be so," he sighed. "Yet we will never know who made these tables, or where. Perhaps it was a Chaldean of Babylon, or a Hindu of India, or a Greek in the far west. Who knows?"

Unless they could discover where the observations had been made, the tables would be useless for exact work. Ptolemy had known, but that great Egyptian had kept the position of the unknown observer a secret.

"In a few days," said Omar quietly, "I will tell you the place of the observations. But now I will sleep."

As he limped from the tower to his own quarters, Mai'mun had one hope. A man who could accomplish one miracle might effect another—although he had never known a miracle to happen in mathematics before. But when he found his assistants gathered disconsolately at his threshold, awaiting him after the morning prayer, the old astronomer lifted his head and thrust out his chin. It might even be said that he swaggered.

"O ye of the classrooms," he said proudly, "Khwaja Omar and I have found the error. After nine hundred years, I have discovered an error in the star tables of Ptolemy the Geographer. In a little while we will correct the error, but now I am weary and would sleep."

Gathering his
abba
about him, he passed into his chamber, having asserted his dignity, and for a moment there was stunned silence among the assistants.

"La Allah il allah,"
whispered one, "Old Fusty hath become drunk also on that wine of Shiraz."

Except for the routine recording of the gnomon's shadow and the minutes of the sunrise and sunset by the water clock, no work was done in the House of the Stars for the following days, save by Omar, who never ceased his labor. He acted, the assistants decided, like one possessed—first calling for a copy of Ptolemy's geography from the library, then for a list of all the Greek astronomers of ancient days.

For the most part he worked in silence, covering sheet after sheet with figures that he passed on to Mai'mun to verify. Mai'mun, helpless when dealing with the unknown, looked on with the fascination of one observing an operation which he does not expect to be successful. He understood readily enough that Omar was seeking the proportion of the error, and using this proportion to calculate the probable distance of the unknown observatory north or south of Alexandria. This, however, could only be approximated—it finally proved to be about five degrees of latitude.

"The observatory of the unknown," Omar said at last, "lies close to five degrees north of Alexandria."

"But why not to the south?"

True, there seemed to be only deserts and unknown mountain ranges on the map south of that point, but Omar was not trusting to the map. He explained that many of the stars in the tables could not be seen from the earth's surface south of Alexandria.

"Nisapur itself lies along that line, to the north," Mai'mun observed, "Ay, and Aleppo, and Balkh and many others."

They decided the point they sought could not be in India; it must be west of Nisapur. Omar believed it to be west of Aleppo, which made their search more difficult because they did not know so much about the ancient cities in the far west.

One evening when they were deep in their tests, a jovial voice saluted them from the entrance.

"Health to the two pillars of wisdom. May your labors be fruitful!"

Omar turned as if pricked by steel, but Mai'mun beheld only Tutush, smiling beneath his blue turban.

"What is this talk," Tutush observed, "in the bazaar of a great discovery made in the House of the Stars?"

Omar dropped his pen and stood up. "It was upon the road I made the discovery," he said calmly, "and it is thou who wilt enlighten me."

"Thy slave to command!" Tutush salaamed, "Thy friend of years—thou hast need only to ask of me."

"I ask in what place thou hast hidden the silver armlet with turquoise inlay. Ay, and the words that were spoken with it?"

The master of the spies had a quick mind, and he recalled the armlet that he had thrown to the girls by the fountain. For an instant he blinked, wondering by what magic the King's astronomer had found out anything about it.

"Ah, there are a million armlets with turquoises! The Khwaja is pleased to jest."

"There was one, given to thee by a jester with a message, in this room. The message thou didst hide from me, and now the death of a girl lieth upon my soul, never to be lifted." Omar's cheeks whitened, and his hands clenched at his girdle. "Now say to me again, Tutush, there are many girls. I loved only one, and
that
thou knewest. And hast lied to me."

He was moving toward the plump master of the spies, and suddenly Tutush became afraid of the eyes that searched his soul. Omar had read his thoughts, and had seen his fear.

"By the Ninety and Nine Names," he cried, "I know naught of this, and I have never set eyes upon any girl of thine.
Hai
, what—Mai'mun—aid!"

Omar's hand gripped his throat and shook him, and Tutush choked like a beast in a snare. The fingers sank into his soft flesh like steel, and his eyes burned in his head. He heard Mai'mun shouting for help, and then, in overmastering fear he snatched a knife from his girdle and struck blindly. The edge of the blade slashed cloth and flesh, grating against bone. Then his wrist was caught and he was flung to the floor.

There he sprawled, sobbing for breath. Looking up through a red mist he beheld Omar fast in the arms of a half-dozen servants and scholars. The cloak was torn over one shoulder, and a dark stain spreading down his breast.

"There is blood between us, dog," said Omar in the same quiet voice, "but it is not this blood. It drips within me a drop at a time, and it is not to be staunched like this. Go, or thou wilt die."

They took Tutush away, and Jafarak who heard the tale from the servants confided to the merchant Akroenos that night by the Takin gate that Omar had been wounded when he set upon the master of the spies in a blind rage. And Akroenos thought so much of this, that after Jafarak had departed, he summoned a runner from the bazaar. He wrote two words on a square of paper and gave it to the man without sealing it.

"Take this," he ordered, "to Ray. Go to the khan of the travelers and cry aloud in the courtyard that thou hast a missive for the Lord of Seven. When he approaches thee, give this to him."