"'The instruction in the university is mostly religious. When his religious course is ended the student is instructed in law, which is always based on the Koran; after that he devotes some attention to poetry, and, if any time remains, he may learn something of geometry, arithmetic, and other miscellaneous knowledge. Many of the students stay in Cairo, to become professors in the El-Azhar or other schools; but those from foreign lands generally return home when their course of study is over, in order to give their own people the advantages of the superior wisdom they have acquired.'" [Illustration: PROFESSORS OF THE EL-AZHAR.] CHAPTER VII. THE CITADEL.--THE TOMBS OF THE CALIPHS.--THE NILOMETER.--THE ROSETTA STONE. [Illustration: THE CITADEL, CAIRO, WITH MOSQUE OF MOHAMMED ALI.] Doctor Bronson told his young friends that the finest general view of Cairo, and the surrounding region, was from the Citadel, at the southern end of the city. They went there several times, generally a little while before sunset, and the impression they received is well described in the following letter from Frank to his mother: [Illustration: VIEW FROM THE CITADEL, CAIRO.] ".... The view from the hill where the Citadel stands has been called the finest in the world, or certainly one of the finest, and in all our travels we do not remember anything that can surpass it. We stood on the platform of the Mosque of Mohammed Ali, and had the great city of Cairo spread at our feet. Immediately below us was an open square, with groups of people and camels moving slowly about. Just beyond was the beautiful Mosque of Sultan Hassan, and beyond the mosque was the plain covered with cupolas and flat roofs, seamed with streets and avenues, dotted with waving palm-trees, and revealing open spaces here and there, to give diversity to the picture. Beyond the city was the bright green of the rich Valley of the Nile. In front of us was the famous old river of Egypt, like a broad, irregular belt of silver, reflecting the light of the setting sun, and forming a sharp contrast with the land through which it flows. Across the green fields, which were stippled with the white walls of palaces or dotted with the brown villages of the peasants, our gaze rested on the yellow desert, backed by the Libyan mountains which form the western horizon. From the edge of the desert the great pyramids rose in all their grandeur, and it was not difficult for us to realize their enormous proportions. From other points the pyramids had appeared to be almost on a level with the valley of the river, but as we viewed them from the Citadel we could see that they stood on a rocky platform fully a hundred feet in height.