The Süleymaniye - Strolling Through Istanbul: The Classic Guide to the City - page 200

were the muvakkithane, the house and workshop of the mosque
astronomer. At the four corners of the courtyard rise the four great
minarets. These four minarets are traditionally said to represent the
fact that Süleyman was the fourth sultan to reign in Istanbul, while
the ten şerefes or balconies denote that he was the tenth sultan of the
imperial line of Osman.
Entering the mosque we find ourselves in a vast almost square
room surmounted by a dome. The interior is approximately 58.5 by
57.5 metres, while the diameter of the dome is 27.5 metres and the
height of its crown above the floor is 47 metres. To east and west
the dome is supported by semidomes, to north and south by arches
with tympana filled with windows. The dome-arches rise from four
great irregularly shaped piers. Up to this point the plan follows that of
Haghia Sophia, but beyond this - as at the Beyazidive - all is diferent.
Between the piers to north and south, triple arcades on two enormous
monolithic columns support the tympana of the arches. There are
no galleries here, nor can there properly be said to be aisles, since
the great columns are so high and so far apart as not really to form
a barrier between the central area and the walls; thus the immense
space is not cut up into sections as at Haghia Sophia but is centralized
and continuous. The method Sinan used to mask the huge buttresses
required to support the four central piers is very ingenious: he has
turned what is generally a liability in such a building into an asset,
on three sides at least. On the north and south he incorporated the
buttresses into the walls of the building, allowing them to project
about equally within and without. He then proceeded to mask this
projection on both sides by building galleries with arcades of columns
between the buttresses. On the outside the gallery is double, with
twice the number of columns in its upper storey as in its lower; on the
inside there is a single gallery only. In both cases - especially on the
outside - the device is extremely successful, and is indeed one of the
things which gives the exterior its interesting and beautiful distinction.
On the east and west façades the buttresses are smaller, for here the
weight of the dome is distributed by the semidomes. On the eastern
face, therefore, Sinan merely placed the buttresses wholly outside the
building, where their moderate projection gives emphasis and variety