necessary, the central apse of the inner apartment was removed and converted into a doorway, and the left-hand lateral apse was also removed so as to make an entrance into four other ovoid apartments, which were arranged radially so as to be covered by a cone 90 feet in diameter. Here again the difficulty, if any, of constructing a cone of these dimensions is got over by the numerous points of support from perpendicular walls which honeycomb the building. The external appearance of this building would be that of one great cone 90 feet in diameter covering the cells, and anastomosing with one 60 feet, or one-third less, in diameter covering the entrance chambers.
Restored in this manner, the external appearance of these monuments would have been very similar to that of the Kubber Roumeia near Algiers and the Madracen near Blidah. The former was 200 feet in diameter, with a cone rising in steps to the height of 130 feet, which was lower in proportion than suggested
