The feeling for variety, in fact, was one great secret of Turkish tile making and tile setting. Sinan, for instance, used tiles very sparingly in his larger buildings. He was great enough to depend very little on ornament for his effect, and he knew that tiles would look like paper or linoleum—if such things existed in his day!—on a monumental surface. But he had a perfect tact of using this tapestry wherever he wanted a touch of colour or distinction—over a window, along a cornice, around a _mihrab_. His masterpiece in this decoration is the mosque of Rüstem Pasha, son-in-law and Grand Vizier to Süleïman the Magnificent. This mosque, lifted on retaining walls above the noise of its busy quarter, has a portico which must have been magnificently tiled—judging from the panel at the left of the main door—and the whole interior is tiled to the spring of the dome. The mosque is small enough for the effect of the tiles to tell—and to be almost ruined by the fearful modern frescoes of the vaulting. The guides of Pera have a favourite legend to the effect that Rüstem Pasha brought back these tiles from his wars in Persia and built a mosque for them to save giving them up to his imperial master. But no one need be an expert to see the impossibility of any such story. The tiles must have been designed for the walls which they incrust, and by a supreme master of decoration. I should not be surprised to learn that Sinan himself drew them all. There is a tall narrow panel on either side of the mosque, between two windows, which seems to me one of the most perfect ways imaginable of filling such a space. So are the spandrels of the arches supporting the gallery, and the niche of the _mihrab_, and the back of the _mimber_. All through the mosque, however, the way in which the artist has varied his designs and colours, while never losing his unity of effect, is a piece of genius. Narrow spaces and points of special interest are treated each in its own way; but unbroken surfaces of wall are never allowed to become monotonous by covering them with only one form of tile. They are broken up by narrower border tiles into panels, each of which is treated differently though harmonising with its neighbour and balancing the corresponding space on the opposite side of the mosque. Even within one of these spaces monotony is avoided by the fact that the tiles are almost never of a repeating pattern. Two or four tiles are required to make up the scheme. And then the pattern does not always fit the tiles, so that the interstices come in different places in different parts of the design, and you feel that the tiles could only have been made for that one space. In the case of special panels, of course, many tiles are required to make up the pattern. The splendid flowered panel in the portico contains forty-five tiles, exclusive of the border, and every one of them different. Such work was not commercial tile making. It was an art.