The _dragon well_[107] may have been near the south end of the pool _Birket-es-Sultan_; indeed there is a tradition among the Arabs, that a spring once existed on this spot, but I do not know whether it is of any value. No remains of the age of Nehemiah are to be found either outside the present city or in its walls, except in the east wall of the _Haram-es-Sherîf_: I will explain my reasons for referring these to this epoch in the chapter on the Temple. No one besides Josephus has handed down to us a detailed account of the topography of Jerusalem in the time of the Herods and Titus: since then he lived in this period and is our sole authority, I follow his account entirely. In endeavouring to identify the spots mentioned by him, in a place that has undergone such frequent alterations, I have not imitated the example of most writers, in ancient and modern times, who have copied one from another, and based their arguments on mere hypotheses; but, during a period of eight years, have devoted myself to a thorough examination of every part of Jerusalem; have carefully studied the _terrain_, the rocks, the stones, which I have sought under the accumulated ruins of centuries; have made deep excavations to trace the course of the ancient walls, underground passages and conduits; have watched the digging of numbers of foundations, from day to day, within and without the city; have collected information from persons worthy of credit and experienced in building, about the most important works that had been carried out before my arrival; have descended into and examined cisterns, clean and dirty; and after working like a labourer during the day, have read Josephus instead of going to sleep, and tested his statements for myself. I did not use any other authors except Livy and Cæsar, whose writings I studied in order to understand thoroughly the Roman art of war and the siege operations of Titus against the city; and after I had done all this, I made plans and sections upon the spot. This being well known to all the inhabitants of Jerusalem, I fearlessly present the results of my labours to all who take an interest in the reconstruction of the city of the Herods. I may indeed sometimes be mistaken in my arguments, or wrong in my conclusions; if so, I shall be glad to be corrected; thankful if even by this means I have created an interest in the subject, and given rise to new ideas and a better knowledge of the archæology of Jerusalem. Having now considered the general features of the city, its hills and its valleys, and seen that it was guarded by a triple wall on the exposed side and a single wall on those which overhung the valleys[108], we will proceed to examine this triple line of defence.