The walls are beyond all doubt, in the main, of Roman construction; though some Saracenic additions have since been incorporated in the work. They are built of squared black basalt, which has weathered externally to a dull yellow tone owing to the lichen which has overspread the surface. Possibly this process was assisted by the fact that some twenty years ago it was deemed a good idea to whitewash them, in order to give a distinguished welcome to a specially prominent Pasha! But fortunately the traces of this sacrilege are almost obliterated now. The houses in the town for the most part are a set of squalid hovels, intersected in all directions by a maze of narrow crooked streets. Our carriage fairly stuck in one of these alleys as we were attempting to pass through it; and for some minutes it seemed problematical whether we should be able to wriggle free. Yet not all the houses are mean; and in the quarter near the citadel, the residence of the chief officials, a very considerable number are solidly constructed of stone. Some few of these are genuinely old, and possess a good deal of interest. They are often built in two colours, with alternate horizontal bands of black basalt and yellow marble, resembling not a little the black and white marble buildings of Pistoia. It is curious how this taste for coloured ornamentation seems inherent in the dwellers in volcanic districts, where materials of different colours are always readily available. The same trait is very conspicuous in the volcanic districts of Auvergne. The most notable example at Diarbekr is a big mansion in the main thoroughfare. A house very similar in type to the old palaces of Spain and Italy; bare, square and prison-like outside, and entered by a single great doorway; but with graceful arcaded porticoes surrounding the _patio_ within. Once, no doubt, it was indeed a palace, the abode of some prominent magnate: but now it is only a _khan_; and a _khan_ so notoriously filthy that even our _Arabaji_ shrank from an encounter with its fleas.