the form of an
obelisk, and once covered with plates of gilded bronze. Under the
Turkish buildings along the western side of the arena, some arches
against which seats for the spectators were built are still visible.

The city was supplied with water mainly from two sources; from the
streams immediately to the west, and from the springs and rain impounded
in reservoirs in the forest of Belgrade, to the north-west, very much on
the system followed by the Turks. The water was conveyed by aqueducts,
concealed below the surface, except when crossing a valley. Within the
city the water was stored in covered cisterns, or in large open
reservoirs. The aqueduct of Justinian, the Crooked aqueduct, in the open
country, and the aqueduct of Valens that spans the valley between the
4th and 3rd hills of the city, still carry on their beneficent work, and
afford evidence of the attention given to the water-supply of the
capital during the Byzantine period. The cistern of Arcadius, to the
rear of the mosque of Sultan Selim (having, it has been estimated, a
capacity of 6,571,720 cubic ft. of water), the cistern of Aspar, a short
distance to the east of the Gate of Adrianople, and the cistern of
Mokius, on the 7th hill, are specimens of the open reservoirs within the
city walls. The cistern of Bin Bir Derek (cistern of Illus) with its 224
columns, each built up with three shafts, and the cistern Yen Batan
Serai (Cisterna Basilica) with its 420 columns show what covered
cisterns were, on a grand scale. The latter is still in use.[1]

Byzantine Constantinople was a great commercial centre. To equip it more
fully for that purpose, several artificial harbours were constructed
along the southern shore of the city, where no natural haven existed to
accommodate ships coming up the Sea of Marmora. For the convenience of
the imperial court, there was a small harbour in the bend of the shore
to the east of Chatladi Kapu, known as the harbour of the Bucoleon. To
the west of that gate, on the site of Kadriga Limani (the Port of the
Galley), was the harbour of Julian, or, as it was named later, the
harbour of Sophia (the empress of Justin II.). Traces of the harbour
styled the Kontoscalion are found at Kum Kapu. To the east of Yeni Kapu
stood the harbour of Kaisarius or the Heptascalon, while to the west of
that gate was the harbour which bore the names of Eleutherius and of
Theodosiur I. A harbour named after the Golden Gate stood on the shore
to