ENGINEER, ARCHITECT

Life
A native of Cnidus, in Caria (Asia Minor), Sostratus was the son of Dexiphanes, the architect of the Tetra Stadium in Alexandria. He is cited by Stobaeus.


Work
His works include:

- The Pharos of Alexandria (280 BC): This great lighthouse was one of the Seven Wonders of the ancient world. Inscribed on the tower was the legend "Sostratus son of Dexiphanes of Cnidus to the gods who protect those at sea". This is recorded by Lucian, who also gives an account of how it came to be written there. Originally called simply "the Lighthouse", the Pharos gradually became known by the name of the small island ('Pharos') on which it was built. This island, which today is connected with the shore, lay just off the eastern entrance to the harbour of Alexandria. The base of the lighthouse measured 340 x 340 metres, and had mighty breakwaters on the three seaward sides, with defensive turrets at the corners. The total height of the structure was 140 metres, making it the tallest building in the ancient world after the Great Pyramids of Khufu and Khefre. It had four storeys above the raised base. The first of these was square, with windows all around illuminating rooms for the guards and engineers, while the centre was occupied by the hydraulic hoist used to bring up food and fuel and other supplies. Above this first floor was an octagonal storey with spiral staircases. The third was circular, and was ornamented with pillars. The fourth storey housed the reflecting mechanism. A fire was kept burning continuously, and a system of delicate instruments reflected the light. The beacon was visible for a radius of 300 stades (~54 km). Crowning the tower was a huge statue of Poseidon. Many sources refer to a huge "mirror", through which one could see ships far out to sea that were not visible to the naked eye. This may have been a form of telescope, with magnifying lenses. The sources also describe a number of automated figures: there was, for example, a statue that tracked the course of the sun across the sky with its finger; there was a mechanical figure that played music to mark the hours, and there was one that sounded an alarm to alert the city to the approach of an enemy fleet before it was visible on the horizon. The Pharos served as a model for many other ancient lighthouses. Ptolemy I allocated the huge sum of 800 talents of silver (about 21000 kg) for its construction, but work was not in fact begun until the reign of his successor, Ptolemy II Philadelphus. It took 12 years to complete. In 500 AD Ammonius made extensive repairs to the base and the breakwaters. Earthquakes in 796, 1100 and 1326 all took their toll of the structure. In 1480 Sultan al-Ashraf Qa'it Bay of the Mamluks built a fortress on the foundations of the ancient Pharos. Renovated in the early years of the 19th century, this fort was razed by the English in 1882.

- The Suspended Pleasure Gardens: At Cnidus, in Caria, Asia Minor. This was a vast pleasure palace with a roof garden, similar in construction to the Hanging Gardens of Babylon. Described by Pliny and Lucian.

- The Clubhouse of the Cnidians: At Delphi, 285 - 272 BC. This was a large colonnaded room, which served as a place of resort for Cnidians visiting Delphi.

- Diversionary canals on the Nile: At Memphis. Major engineering project to drain the main channel of the river in order to allow Ptolemy II to capture the besieged city. Described by Lucian.