This story appeared as a preface to Borja Martinez’s PhD Thesis.
The library of Alexandria, abuzz with conversations, lectures and other activities on most days, was quiet.
It was a hot day; one of the hottest that Alexandria had seen in many years. Scholars, scientists, philosophers, mathematicians, artists, historians, students, teachers and scribes, had arrived at the library that morning and then within minutes, decided to shirk work for the day and go to the seaside for a swim. Only one of the scholars, the head librarian, Eratosthenes, had been in disagreement with this plan
The last month had been busy – summer solstice had come and gone and a trade ship from Cyrene had arrived carrying books by Homer. As was the command of the king and the rule of the land, each of the books had been confiscated and then painstakingly copied at the library, so that the originals could have a new home. The copies were so perfect that the captain of the ship hadn’t realized that he was being returned something he had never owned.
Eratosthenes, who had a particular fondness for the Odyssey, had orchestrated the creation of a new section in the library for Homer’s works. He sat in this room now, by a window overlooking the port, glad that he had the space to himself.
In a rare moment of indulgence – it wasn’t often that he allowed himself to reread his own work – he was busy copying something he had written a few years ago; Chronographies. This was a text so accurate in its history of key events that Ptolemy III Euergetes, the king of Alexandria and father of Eratosthenes’ primary pupil, Philopator, had read it a few years ago and urged him to accept the prestigious role of head librarian at the library of Alexandria.
Eratosthenes was writing the name of the 37th king of the Egyptian Thebes, when a voice jolted him out of his concentration. It was a voice full of energy and curiosity, the voice of a young prince still not sullied by the weight of the responsibility that would come to him.
‘Master!’ the voice said, ‘I have come back from Syene.’
‘Oh, it’s you, Philopator. Why aren’t you at the sea with the others?’
‘I had to come and talk to you Master. No one else will believe me, not even my mother!’
‘What are you talking about child? Calm your mind and tell me.’
‘Well, last week, one afternoon, we were on the island in Syene. Mother was thirsty so she asked me to get her some water from the well. But Master, when I looked inside the well, there was no shadow. When I told mother and the others, they said I must be seeing things or that I must have done something to displease the Gods.’
‘Philopator, how is that possible? You know that everything casts a shadow. We studied it together, don’t you remember?’
‘I remember, Master, but I saw what I saw. And that day at noon, it was the 21st of June -mother told me that is the day of the solstice – there was no shadow in the well,’ Philopator paused, ‘Master, you believe me, don’t you?’
Eratosthenes looked at him. He knew that the prince, although wild in his imaginations, would not make up a tale or utter a lie to a teacher he so respected.
‘Alright, Philopator, I will believe you. I do not know why you saw what you saw, but I give you my word that I will try to find a reason for this strange occurrence. Now leave me with my work and go and play with the others. May the Gods be with you.’
Satisfied, that at last, he had found a patient listener, Philopator ran out, leaving the head librarian in solitude once again.
For the rest of the day, Eratosthenes found that he couldn’t concentrate on editing the Odyssey anymore. His student, at the age of ten, had posed him a question that he couldn’t answer and it consumed him.
A year passed and Eratosthenes found that he couldn’t focus on anything for too long. Why did the sunlight bound off the water in Syene and not in Alexandria? Why was there always a shadow in Alexandria? Why wasn’t anyone except Philopator shocked by this?
On one such day of distractions, the day of the solstice, Eratosthenes found that he was in the company of young Philopator again. They had come out of the library for a walk because neither of them had been able to concentrate on their lesson, the teacher, annoyed that he still hadn’t found an answer to a child’s question and the student, too hot to study.
After they walked for a while, they arrived at a well. Philopator stopped.
‘Master, I’m thirsty, shall we get some water?’
He had already picked up a stick so he could draw out the water from the well using the pail that lay by its side. It was midday, the stick had a shadow.
‘Philopator!’ Eratosthenes exclaimed, ‘Stay there, stay exactly as you are, I’ll be right back.’
He came back after a few minutes, bringing with him his measuring instruments.
‘Look, Philopator, the sun is above us but the stick casts a shadow at an angle. Right now, the sun is above Syene, on the island you were last year with your mother, but I am positive that the same stick would cast no shadow there. Come, let us make haste and return to the library. I think I know now what I must do.’
Philopator’s face had lit up, as though a memory of the past had resurfaced in his mind. ‘I knew you would find an answer, Master. But what is it that you have to do?’
Eratosthenes smiled, ‘My dear Philopator, I believe I am going to find out the size of our beloved Earth.’
Centuries later, an explorer called Christopher Columbus would refer to the works of Eratosthenes and choose to ignore the scholar’s calculations of the size of the Earth. If he hadn’t done so, he might have arrived at the destination he had originally intended to arrive at – India.