Alexander the Great decides that the small Egyptian port of Rhacotis is a natural base for future operations in the eastern Mediterranean. It is close to the delta of the mighty Nile, but far enough removed to avoid silting up; it has a protective island, Pharos, a little way offshore; and it is well placed for trade or warfare with the middle east. He builds a new suburb beside the old town (inhabited already for more than 1000 years) and calls old and new jointly after himself – Alexandria.
Under Ptolemy, Alexander’s successor in Egypt, the new city begins a glittering career.
Ptolemy adds legitimacy to his rule in Egypt by acquiring Alexander’s body. He intercepts the embalmed corpse on its way to burial, brings it to Egypt and places it in a golden coffin in Alexandria.
It will remain one of the famous sights of the town for many years, until probably destroyed in riots in the 3rd century AD.
Alexandria as a capital city: from about 320 BC
Ptolemy recognizes in Alexandria the natural advantages which had attracted Alexander to the site. He makes it his capital and begins to transform it into one of the greatest centres of learning in the Greek world.
He founds here in Egypt what is in effect a university, though the word he uses for it is ‘museum’, home of the Muses. Mathematicians of the stature of Euclid, Archimedes and Eratosthenes will be connected with this academy. Its library becomes the greatest in the ancient world. And immigrants from elsewhere in the eastern Mediterranean soon turn this relatively new place into a great cosmopolitan centre.
The Jews of Alexandria demonstrate the ability of a Jewish community to flourish in a new context without losing its identity. They integrate so fully with the secular life of the city that their own first language becomes Greek. It is they who first use the word diaspora (Greek for ‘dispersion’) to describe Jewish communities living outside Israel.
Soon many of them no longer understand Hebrew. But they refuse to let this diminish their strong sense of a shared identity as God’s special people, according to the covenant revealed in a book which they now cannot read. They commission, with Ptolemy’s support and approval, the first translation of the Bible, the famous Greek version known as the Septuagint.
In addition to the library, Ptolemy plans the great lighthouse on the island of Pharos at the entrance to the harbour. It is built in about 280, under his successor Ptolemy II.
It is by far the most impressive lighthouse of antiquity, becoming famous as one of the Seven Wonders of the World.
The lighthouse consists of a three-tier stone tower, said to be more than 120 metres high, which has within it a broad spiral ramp leading up to the platform where fires burn at night. They are reflected out to sea by metal mirrors. Above the fires is a huge statue, of either Alexander or Ptolemy in the guise of the sun god, Helios.
The lighthouse survives until the 12th century. In the 15th century a fort, still standing today, is built from its ruins.
Greek science in Alexandria: from the 3rd century BC
Classical Greece has produced a brilliant tradition of theorists, the dreamers of science. Attracted by the intellectual appeal of good theories, they are disinclined to engage in the manual labour of the laboratory where those theories might be tested.
This limitation is removed when the centre of the Greek world transfers, in the 3rd century BC, to Alexandria. In this bustling commercial centre, linked with long Egyptian traditions of skilled work in precious metals, people are interested in making practical use of Greek scientific theory. If Aristotle says that the difference in material substances is a matter of balance, then that balance might be changed. Copper might become gold.
Among the practical scientists of Alexandria are men who can be seen as the first alchemists and the first experimental chemists. Their trade, as workers in precious metals, involves melting gold and silver, mixing alloys, changing the colour of metals by mysterious process.
These are the activities of chemistry. The everyday items of a chemical laboratory – stills, furnaces, flasks – are all in use in Alexandria.
Euclid and Archimedes: 3rd century BC
Euclid teaches in Alexandria during the reign of Ptolemy. No details of his life are known, but his brilliance as a teacher is demonstrated in the Elements, his thirteen books of geometrical theorems. Many of the theorems derive from Euclid’s predecessors (in particular Eudoxus), but Euclid presents them with a clarity which ensures the success of his work. It becomes Europe’s standard textbook in geometry, retaining that position until the 19th century.
Archimedes is a student at Alexandria, possibly within the lifetime of Euclid. He returns to his native Syracuse, in Sicily, where he far exceeds the teacher in the originality of his geometrical researches.
Human vivisection: c.300 BC
Early in the 3rd century BC two surgeons in Alexandria, Herophilus and Erasistratus, make the first scientific studies designed to discover the workings of human anatomy.
The cost of their contribution to science would be considered too high in modern times (they acquire much of their information from vivisection of convicted criminals). But Celsus, a Roman writer on medical history, energetically justifies the suffering of the criminals as providing ‘remedies for innocent people of all future ages’.
Mechanical organ: 3rd century BC
Pipes of varying sorts are among the earliest of musical instruments, and pipers must often have imagined a pipe too large for human lungs. A scientist in Alexandria, by the name of Ctesibius, is credited with being the first to invent an organ – with a hand-operated pump sending air through a set of large Pipes. Each pipe is played by pressing a note on a board. This is the beginning of keyboard instruments.
By the time of the Roman empire, a few centuries later, the organ is a familiar and popular instrument – playing a prominent part in public games and circuses as well as private banquets. The emperor Nero, an enthusiastic performer, is proud of his talents on the organ.
The circumference of the earth: calculated c. 220 BC
Eratosthenes, the librarian of the museum at Alexandria, has more on his mind than just looking after the scrolls. He is making a map of the stars (he will eventually catalogue nearly 700), and he is busy with his search for prime numbers; he does this by an infinitely laborious process now known as the ‘sieve of Eratosthenes’.
But his most significant project is working out the circumference of the earth.
Eratosthenes hears that in noon at midsummer the sun shines straight down a well at Aswan, in the south of Egypt. He finds that on the same day of the year in Alexandria it casts a shadow 7.2 degrees from the vertical. If he can calculate the distance between Aswan and Alexandria, he will know the circumference of the earth (360 degrees instead of 7.2 degrees, or 50 times greater).
He discovers that camels take 50 days to make the journey from Aswan, and he measures an average day’s walk by this fairly predictable beast of burden. It gives him a figure of about 46,000 km for the circumference of the earth. This is, amazingly, only 15% out (40,000 km is closer to the truth).