The eastern part is composed of six galleries; those of the west are supported by nineteen pillars. The apertures are each six feet and a half wide, and ten or eleven high. The workmanship, though pretty well executed, is, as I have already observed, far from equalling that of the other quarter. The first three galleries on the east side, are one hundred and four ordinary paces[7] long, and about two and a half broad: the three next are only sixty-four long. The length of those on the west is only thirty nine paces. They lead to the great tower, which faces an inner court, closed on the west by the ruins. It is of a square form, but terminates in a small truncated pyramid, which is also built of brick and surmounted by a pot of baked earth. Its height may be estimated at fifty or fifty-five feet from the base to the summit. The steps of the staircase, which is constructed internally, are supported by pieces of wood fixed in the walls and covered with earth. The dilapidated state of the staircase prevented me from ascertaining the exact number of the steps, but I observed the traces of thirty-two. [Illustration: SKETCH OF THE PLAN OF THE GREAT MOSQUE OF TIMBUCTOO, AND VIEW TAKEN FROM THE E. N. E.] [Illustration: 1, 4, 3, DETAILS OF THE GREAT MOSQUE OF TIMBUCTOO; 4, 5, PLAN AND FRONT OF THE HOUSE OF SIDI ABDALLAH CHEBIR, IN WHICH MR. CAILLIÉ RESIDED.] The walls of the mosque are fifteen feet high and twenty-five or twenty-six inches thick. The top of the wall of the east front is indented in the form of battlements, the salient parts of which are surmounted by pots of baked earth, similar to that on the summit of the tower. Another massive tower, of a conical form, surmounts the front wall. It is about thirty feet high. On the dome, projecting pieces of wood are perceptible, the use of which seems to be to unite the masonry. The roof of the mosque has a terrace like that of the tower, and is moreover surrounded with a parapet eighteen inches high. The roof of the building is supported by rafters, formed of the trunks of the ronnier tree split into four, and placed at the distance of a foot from each other. Pieces of salvadora wood, brought from Cabra, where it grows in great abundance, cut to the length of the intervals between the rafters, are placed obliquely in double rows, crossing each other. Over these are laid mats made of the leaves of the ronnier, which are covered with earth. This mosque has five gates of different sizes on the eastern side, three on the south side, and two on the north. On the western side the ruins form at once the boundary of the mosque and of the city. On the eastern and northern sides, the floor of the building is level with the ground; but on the south is an ascent of four steps.