274 INDIAN SARACENIC ARCHITECTURE. BOOK VII. apartment, 135 ft. 5 in. each way; its area consequently is 18,337 sc l- ft- wm l e tnat f the Pantheon at Rome is, within the walls, only 15,833 sq. ft. ; and even taking into account all the recesses in the walls of both buildings, this is still the larger of the two. At the height of 57 ft. from the floor-line the hall begins to contract, by a series of pendentives as ingenious as they are beautiful, to a circular opening 97 ft. in diameter. On the platform of these pendentives at a height of 109 ft. 6 in., the dome is erected, 124 ft. 5 in. in diameter, thus leaving a gallery more than 12 ft. wide all round the interior. Internally, the dome is 178 ft. above the floor, and externally 198 ft. from the outside platform ; its thickness at the springing is about 10 ft, and at the crown 9 ft. The most ingenious and novel part of the construction of 416. Pendentives of the Tomb of Muhammad, looking upwards. (From a Drawing by Mr Gumming.) Scale 50 ft. to i in. this dome is the mode in which its lateral or outward thrust is counteracted. This was accomplished by forming the pendentives so that they not only cut off the angles, but that, as shown in the plan, their arches intersect one another, and form a very considerable mass of masonry perfectly stable in itself; and, by its weight acting inwards, counter- acting any thrust that can possibly be brought to bear upon it by the pressure of the dome. If the whole edifice thus
