Pharos of Alexandria
Of the Seven Wonders of the Ancient World, only one had a practical
use in addition to its architectural elegance: The Lighthouse of Alexandria.
For sailors, it ensured a safe return to the Great Harbor. For architects, it
meant even more: it was the tallest building on Earth. And for scientists, it
was the mysterious mirror that fascinated them most... The mirror which reflection
could be seen more than 50 km (35 miles) off-shore.
On the ancient island of Pharos, now a promontory within the
city of Alexandria in Egypt.
Shortly after the death of Alexander the Great, his commander
Ptolemy Soter assumed power in Egypt. He had witnessed the founding of Alexandria,
and established his capital there. Off of the city's coast lies a small island:
Pharos. Its name, legend says, is a variation of Pharaoh's Island, but it is
more likely that the name is Greek in origin. The island was connected to the
mainland by means of a dike - the Heptastadion - which gave the city a double
harbor. And because of dangerous sailing conditions and flat coastline in the
region, the construction of a lighthouse was necessary.
The project was conceived and initiated by Ptolemy Soter around 290 BC, but
was completed after his death, during the reign of his son Ptolemy Philadelphus.
Sostratus, a contemporary of Euclid, was the architect, but detailed calculations
for the structure and its accessories were carried out at the Alexandria Library/Mouseion.
The monument was dedicated to the Savior Gods: Ptolemy Soter (lit. savior) and
his wife Berenice. For centuries, the Lighthouse of Alexandria (occasionally
referred to as the Pharos Lighthouse) was used to mark the harbor, using fire
at night and reflecting sun rays during the day. It was even shown on Roman
coins, just as famous monuments are depicted on currency today.
When the Arabs conquered Egypt, they admired Alexandria and its wealth. The
Lighthouse continues to be mentioned in their writings and travelers accounts.
But the new rulers moved their capital to Cairo since they had no ties to the
Mediterranean. When the mirror was brought down mistakenly, they did not restore
it back into place. In AD 956, an earthquake shook Alexandria, and caused little
damage to the Lighthouse. It was later in 1303 and in 1323 that two stronger
earthquakes left a significant impression on the structure. When the famous
Arab traveler Ibn Battuta visited Alexandria in 1349, he could not enter the
ruinous monument or even climb to its doorway.
The final chapter in the history of the Lighthouse came in AD 1480 when the
Egyptian Mamelouk Sultan, Qaitbay, decided to fortify Alexandria's defense.
He built a medieval fort on the same spot where the Lighthouse once stood, using
the fallen stone and marble.
Of the six vanished Wonders, the Lighthouse of Alexandria was
the last to disappear. Therefore we have adequately accurate knowledge of its
location and appearance. Ancient accounts such as those by Strabo and Pliny
the Elder give us a brief description of the "tower" and the magnificent
white marble cover. They tell us how the mysterious mirror could reflect the
light tens of kilometers away. Legend says the mirror was also used to detect
and burn enemy ships before they could reach the shore.
In 1166, an Arab traveler, Abou-Haggag Al-Andaloussi visited the Lighthouse.
He documented a wealth of information and gave an accurate description of the
structure which helped modern archeologists reconstruct the monument. It was
composed of three stages: The lowest square, 55.9 m (183.4 ft) high with a cylindrical
core; the middle octagonal with a side length of 18.30 m (60.0 ft) and a height
of 27.45 m (90.1 ft); and the third circular 7.30 m (24.0 ft) high. The total
height of the building including the foundation base was about 117 m (384 ft),
equivalent to a 40-story modern building. The internal core was used as a shaft
to lift the fuel needed for the fire. At the top stage, the mirror reflected
sunlight during the day while fire was used during the night. In ancient times,
a statue of Poseidon adorned the summit of the building.
Although the Lighthouse of Alexandria did not survive to the present day, it
left its influence in various respects. From an architectural standpoint, the
monument has been used as a model for many prototypes along the Mediterranean,
as far away as Spain. And from a linguistic standpoint, it gave its name --
Pharos -- to all the lighthouses in the world... Just look up the dictionary
for the French, Italian, or Spanish word for lighthouse.