CAUSE OF DILAPIDATION TO ENTRANCE BUTTRESSES
The entrance buttresses with portcullis grooves are in most instances comparatively small, some projecting only two to three feet towards the interior of the building, and these are built up against main and divisional walls, and are in point of construction altogether independent erections, there being no dovetailing or binding between the buttresses and the walls.
In some of the entrances the side lintels of slate, granite, and unworked soapstone beams have been found built into the portcullis grooves. In The Ancient Ruins of Rhodesia it was noticed that at several of the ruins therein mentioned stone side lintels were found in situ. The stone lintel posts in situ at Zimbabwe had not then been discovered. The tallest of such stone lintels at Zimbabwe is 8 ft. above the ground. The buttresses appear to have been built after the stone posts had been erected, for the walls at the sides of the lintel follow the irregularities of the side faces of the beams.
The great destruction which has occurred to these structures might possibly be accounted for by (1) the weight of the stone lintel on getting off the perpendicular, which would lever down the buttress into which it was built; (2) the foundations of buttresses are not so deep as those of the main wall up against which they were built; (3) when some later people, possibly natives, deliberately built up and blocked the entrances they might have used the blocks of these buttresses for their building material; (4) the passage-way between each pair of buttresses being so very narrow, damage could easily have been wrought by ordinary traffic; and (5) the main walls are much higher than the summits of the buttresses, and the walls on either side of the entrances being always more dilapidated on the summits, the falling of huge masses of masonry on to the buttresses immediately below might have effected their destruction.
CHAPTER VIII
NOTES ON ANCIENT ARCHITECTURE AT GREAT ZIMBABWE
(Continued)
Drains—Battering of Walls—Monoliths—Soapstone Monoliths and Beams—Granite and Slate Beams—Cement dadoes—Built-up Crevices—Holes in Walls other than Drains—Blind Steps and Platforms—Ancient Walls at a Distance from Main Walls—Cement—Caves and Rock Holes.