The most important lectures are delivered during the forenoon and in the evening. A walk, at one of those hours, through the square and under the colonnades of the mosque, with ears opened to all sides, will enable you to get a general idea of the objects of mental exercise of this international assembly. Here you may find a sheikh of pure Arab descent explaining to his audience, composed of white Syrians or Circassians, of brown and yellow Abyssinians and Egyptians, of negroes, Chinese, and Malays, the probable and improbable legal consequences of marriage contracts, not excepting those between men and genii; there a negro scholar is explaining the ontological evidence of the existence of a Creator and the logical necessity of His having twenty qualities, inseparable from, but not identical with, His essence; in the midst of another circle a learned _muftî_ of indeterminably mixed extraction demonstrates to his pupils from the standard work of al-Ghazâlí the absolute vanity of law and doctrine to those whose hearts are not purified from every attachment to the world. Most of the branches of Mohammedan learning are represented within the walls of this temple by more or less famous scholars; and still there are a great number of private lectures delivered at home by professors who do not like to be disturbed by the unavoidable noise in the mosque, which during the whole day serves as a meeting place for friends or business men, as an exercise hall for Qorân reciters, and even as a passage for people going from one part of the town to the other. In order to complete your mediaeval dream with a scene from daily life, you have only to leave the mosque by the Bâb Dereybah, one of its twenty-two gates, where you may see human merchandise exhibited for sale by the slave-brokers, and then to have a glance, outside the wall, at a camel caravan, bringing firewood and vegetables into the town, led by Beduins whose outward appearance has as little changed as their minds since the day when Mohammed began here to preach the Word of Allah.