Said al-Ghazali craned his neck upward. His whole world had now been reduced to a blue disc, a circle of intense colour set in a sea of impenetrable inky blackness. And what was worse, the disk was shrinking in small steady increments, each one accompanied by a slight jerk as he continued his unsteady progress. Faint wisps of cloud passed over the blue, and al-Ghazali felt his helplessness yet more intensely. Not for the first time did he question the sanity of this venture.
The blackness suddenly ate into the blue disc, an irregular shape appearing at the circumference. Al-Ghazali was momentarily startled, and reached out with both hands. He touched cold, damp, rough-hewn stone.
“Is everything all right, master?” The voice came to his ears somewhat indistinctly, ringing, echoing off the stone.
Al-Ghazali squinted. The shape at the edge of the disc resolved itself into a head and shoulders, and he recognised the voice as that of the young villager he had paid to lower him into the well. He had given him half in advance, as surety that he would be safely brought back to the surface, although at the same time, he knew that the well was far too precious for the village to waste by leaving him floating in it.
“Is it nearly time?” al-Ghazali called up. He wasn’t sure how well his voice would carry.
“Yes, master,” came the reply. “Just a few moments more.” And then the silhouetted figure retreated, restoring the former perfect geometry of the blue disc.
Al-Ghazali shifted awkwardly in the bucket, his knees crammed against his chest, his muscles beginning to ache, while his arms hung uselessly outside. He was getting too old for this sort of thing, he told himself. He was, after all, nearly seventy, and…
He gasped in shock and pain. Brilliant white light flooded over him, stabbing at his retinas with a ferocity that he could not have imagined. In a moment he had covered his face with his hands, desperately blocking out the light, and he felt the tears rolling over his lined and leathery cheeks.
It seemed to last forever. And then, through the gaps between his fingers, he saw that it had gone.
“Master?” The young man called down to him.
Al-Ghazali looked upward once more. The blue disc was a pale blur, perceived through watering eyes. “Yes?” he called. His own voice sounded terribly faint.
“Have you seen what you wanted to see, master?”
What, al-Ghazali wondered, did the young man think that he was expecting to see? The Koran spoke of Allah’s Seventy Thousand Veils of Light and Darkness. It was as if he had been swathed first in one of utmost darkness, and then in one of utmost light. Was this Allah’s way of showing him the stark contrast between ignorance and truth? “Yes,” he said. “Thank you.”
“Do you wish me to pull you up now, master?” the young man inquired.
“Yes,” said al-Ghazali, unable to conceal his anxiety. “Please.”
The ascent was jerkier and more unpleasant than the descent, but al-Ghazali had what he had come for, and looking up at the blue disc, which was now slowly growing larger, he muttered a prayer of gratitude that the knowledge he had been granted had not been bought at the expense of his eyesight. The only unknown now was whether or not Abdul had done his part correctly, but his grandson was a diligent lad and a good scholar, and he had no reason to doubt that the boy had carried out his instructions. But it would be many days before he would know for certain.
When he reached the top, eager hands were there to help him out of the bucket. They pulled him over the lip of the well, and made sure he was steady on his feet.
Only too happy to complete his part of the bargain, al-Ghazali at once opened his purse, and counted some coins into the young man’s hands.
The young man’s enquiring eyes fixed him with remarkable penetration. “What did you see, master?” he asked.
“The sun,” al-Ghazali said simply.
The young man looked at him as if he had perhaps been in the sun a little too long. “But, master,” he faltered, “we can all see the sun from here.” Shielding his eyes, he pointed up to where the great glowing orb continued its uncaring progress across the vault of heaven. “Why do you need to go down a well to see the sun?”
Al-Ghazali pondered. It was a very reasonable question. The problem was, how to answer it in a way that the young man might understand, and hopefully without appearing to be insane. There was no way, he concluded. “Because it looks different from down there,” he said simply.
The villagers who had pulled him from the well concluded that he was indeed a madman. Some looking apprehensive, others amused, many making gestures that indicated what they thought of his mental health, the village men wandered away.
A veiled woman with a basket of dates walked past, and as al-Ghazali still had his purse open, he offered he a coin and pointed to the dates. Her eyes flashed, and she inclined her head gracefully in his direction.
He took the dates and settled himself on a low mudbrick wall, under the shade of an olive tree. From there, he had a good view of the well, and could also see the sun high up, glimpsed through the branches of the tree. As he began to eat dates, he reflected on the ancient Egyptians, who revered the scarab beetle because they believed that it rolled the sun across the sky like a ball of dung. That was surely wrong, he thought, for if there was anything that resembled a ball of dung, it was the world upon which men lived their lives. Whether it was made of dung was, he supposed, a matter of philosophy - although there were certainly times when he believed it to be so - but as for it being a ball, well many of the ancients had thought it to be round, and provided Abdul had done his part, he, al-Ghazali, would be able now to prove it beyond the shadow of a doubt.
He looked again at the well. It was a simple, unassuming thing, identical to countless others. But this was the well at Syene. Over seventeen hundred years previously, in 230 BC, the Greek thinker Eratosthenes had come here, at the time of the summer solstice, just as al-Ghazali had done, and looking into the well, that well there, had seen that the sun was directly overhead. He had not only been able to show from this that the Earth was round, but moreover, had been able to offer a calculation of its size. But for al-Ghazali, that would all depend on his grandson.
He settled in with his back against the wall, where the shade was deepest, and waited while the scarab continued to roll the sun across the sky.
When evening came, a cool breeze wafted up from the Nile, carrying with it the inviting aromas of cooking fires, and al-Ghazali began to feel hunger pangs. Still savouring the sweet dates, he began the walk back to the river. Not far upstream was the First Cataract, where the world’s mightiest torrent swept over rocks and shallows. Since the time of the first kings, this place had marked the southern extremity of the vast Kingdom of Egypt.
The felucca was still tied up at the landing stage where he had left it that morning. He went aboard and settled into his accustomed place in the stern, drawing his cloak in around himself. The first stars began to come out in the clear evening sky.
In the first light of morning, the crew of the felucca cast off, and she manoeuvred into midstream. Carried by the current, she made good speed. Al-Ghazali put his hand into a small linen bag that he carried on his belt and pulled out a few of the cardamom seeds that he habitually chewed, and popped them into his mouth. He watched as Syene slipped from view astern, and readied himself for the long voyage northward to Alexandria, five hundred miles away, at the other end of Egypt.
Al-Ghazali spun sharply at the sound of a familiar voice. He was working his way through the crowded streets of Alexandria, heading towards the inn, which was their rendezvous. He had been keeping a close lookout for his grandson, but of course the boy, with his far sharper eyesight, had spotted him first.
Abdul embraced the old man, almost knocking the wind out of him, and al-Ghazali returned the embrace, grateful to see him hale and hearty. Although he thought of Abdul as a boy, he was, al-Ghazali recognised, almost a grown man, and indeed already talking of making the Haj, the pilgrimage to Mecca, which every good Moslem was required to undertake, if humanly possible, once in his lifetime. Nevertheless, this was Alexandria, a port city, full of all kinds of dangers and temptations, and he was relieved to see that he had survived unscathed. Perhaps, al-Ghazali mused, it was best not to inquire too closely into how the young man had passed the time in his absence.
“So,” he said brightly, as they began to pick their way through the crowds, “what do you have to tell me?”
“Seven point two degrees’ angle of incidence! Just as Eratosthenes had it!” Abdul shouted, with as much passion as if he were announcing that he was in love.
“Very good,” said al-Ghazali, patting him on the back. “And have you done the calculation?”
“Yes, of course,” his grandson beamed. “It’s all back in the room.”
When they reached the small upstairs room, Abdul handed his grandfather the paper. Using an inkwell to weight one corner, he set it down on a small table under the window. Outside, the street bustled with people, traders of all different races, faiths and backgrounds, come together to do business in the city that Alexander the Great built, where the Nile met the sea. The air was filled with the sound of voices, and it was thick with dust, and the rich aroma of exotic spices. Under the window, a camel lumbered past, heavily laden with rugs.
Al-Ghazali closed his mind to all of it. “Let us see,” he began. He was speaking as if to edify Abdul, but it was as much to assure himself of the facts he had before him. “The sun is overhead at Syene at noon on the solstice. On the same day, at the same time, a post in Alexandria casts a shadow of such and such a length. As you observe, my boy, this gives an angle of incidence of seven point two degrees.” He tapped the figure on the paper gently with his finger to emphasise the point. “The first thing that this proves is…?”
“That the world is round!” said Abdul, ever the eager pupil. “The ancients were correct!”
“Good,” said al-Ghazali approvingly. “Now, I see you have completed the calculation. The distance from Alexandria to Syene is four hundred and ninety miles, essentially due south. So, if we divide the circumference of the world into three hundred and sixty degrees, we can make the following equation. Seven point two over three hundred and sixty is equivalent to four hundred and ninety over the unknown circumference, which we can call X. And the solution, which you have here, is twenty-four thousand, five hundred and ninety miles.”
He looked at Abdul. The boy’s expression was downcast.
“I know, I know,” he murmured. “The figure is absurd. I have been over the calculation a hundred times. I cannot see where I have made my mistake. I suppose you will show me now, and I will look like a fool.”
“I believe,” said al-Ghazali softly, aware of the import of what he was saying, “that there is no mistake in your calculations.”
Abdul looked at him uncomprehendingly. “But… that would mean that the parts of the world that are unknown are vastly greater than those which are known!”
The old man’s eyes fixed his. They were filled with warmth and assurance. “Is that so unthinkable?” al-Ghazali said. “Have we become so filled with overweening pride that we believe we know all there is to know about the world? I think not!”
“But such enormous unknown spaces!” said Abdul. “What unvisited lands might there be? And what people might inhabit them?”
“It will probably not be granted to us to know,” his grandfather said. “But I agree, the prospect is intoxicating!”