Around the Blue Mosque - Strolling Through Istanbul: The Classic Guide to the City - page 109

water taps in the outer courtyard, beneath the graceful arcade which
forms part of the north and south walls of the avlu.
The main entrance to the mosque itself is at the eastern side of the
courtyard, with smaller entrances from the outer courtyard beside
the central minarets on the north and south sides. (Tourists are asked
to enter through the south door and are restricted to the west end of
the prayer hall.)
The interior plan of Sultan Ahmet Camii, like that of Yeni
Cami and other imperial mosques, recalls in a general way that of
Haghia Sophia; but in this case the diferences are greater than the
resemblance. It is very nearly a square (51 metres long by 53 metres
wide) covered by a dome (23.5 metres in diameter and 43 metres
high), resting on four pointed arches and four smooth pendentives.
To east and west are semidomes, themselves flanked by smaller
ones. So far, it is not unlike Haghia Sophia. But in Sultan Ahmet,
instead of tympanic arches to north and south, there are two more
semidomes, making a quatrefoil design. This so-called “centralized”
plan would seem to have two disadvantages: the reiterated symmetry
becomes lifeless and tedious, and it gives too much prominence to
the necessarily bulky piers that support the dome. In this case, the
architect has gone out of his way to call attention to these supports
by making them colossal, clear-standing columns, five metres in
diameter, and has emphasized their squatness by dividing them in
the middle by a band and then ribbing them above and below with
convex flutes. The efect is somewhat disconcerting; nevertheless one
has the impression that the mosque interior is in general the most
admired in the city.
The mosque is flooded with light from its 260 windows. These
were once filled with coloured glass which would have tempered the
too-crude brightness; now they are slowly being replaced with modern
imitations. The painted arabesques in the domes and upper parts of
the building are feeble in design and crude in colouring, as almost
always in these modern imitations of a type of decoration that was
in the sixteenth and seventeenth centuries richly elaborate in design
and somberly magnificent in colour. Here the predominant colour
is a rather blatant blue, from which the building derives its popular