Constantinople is full of stories and legends of the same sort, in most of which figures a secret passage leading underground to St. Sophia. I have poked my own nose into two or three such tunnels, which no Turk ever constructed, and can vouch for their existence. In reality, however, there is nothing very mysterious about them. The soil of Stamboul is honeycombed with cisterns of all sizes, from the enormous ones picturesquely called by the Turks the Sunken Palace and the Thousand and One Columns to the small one of the Bible House and Valideh Han. Others, like the cistern beside the mosque of Sultan Selim I, were always uncovered. These are usually called _choukour bostan_, hollow garden, from the fact that vegetable gardens are wont to flourish in the accumulated silt of their centuries. Brick conduits connect many of the reservoirs with a water-system which Hadrian is known to have installed or enlarged while Rome was still the capital of the empire. And it was only natural for such conduits to lead toward St. Sophia, the civic centre of the town. We also know that Constantine constructed deep sewers, on the lines of the _cloaca_ of Rome. But as no one has ever been able to study these systems thoroughly, there remains something half mythic about them. [Illustration: The Myrelaion] Another casual but more dramatic way in which old Constantinople proves her temper of eternity is by means of the fires that periodically ravage Stamboul. There is no more striking suggestion of Stambouls within Stamboul than to look at the ashes of some familiar, of some regretted quarter, and discover there a solid piece of antiquity about which houses have been built and burned who knows how many times. In my own day the Column of Marcian has reappeared on its hilltop overlooking the Marmora, having long been lost in the yard of a Turkish house. And I have seen the obscure mosque of Boudroun Jami gallantly reassert itself above the ruin of its quarter as the charming little tenth-century church of the Myrelaion—the convent of Myrrh and Oil. The fires which an archæologist might best have been suspected of setting were those of 1912 and 1913, which swept the slope between the Hippodrome and the Marmora. This was the site of the Sacred Palace of the later Roman emperors. No complete account of it remains, but from the reports of ambassadors and other visitors of note, from references of historians, and from the Book of Ceremonies of the emperor Constantine Porphyrogenitus, scholars have been able to reconstitute that city of palaces, churches, terraces, and gardens that overlapped on one side a corner of the present Seraglio grounds and reached on the other nearly to the church of SS. Sergius and Bacchus. Constantine the Great was the founder of this imperial residence. His Palace of Daphne, so called from a statue of the nymph he brought from Rome, stood on the site of the mosque of Sultan Ahmed I,