5o8 Report S.A.A. Advancement of Science. 



So noticeable is this feature in the main walls of the Elliptical 

 Temple that visitors viewing the walls from the interior constantly 

 affirm their belief that the walls have commenced to lean over 

 towards tne interior, and when viewing the exterior faces of the 

 identical walls, declare that the walls are leaning inwards, and must 

 ultimately fall inside the building. This is a mere optical delusion. 



The main walls, portions of which are believed tO' have .stof»d 

 some 3,500 years, are. if given the same conditions, quite likely to 

 be standing at the end of another millennium, if not longer, for the 

 battering back is but an important element of their massive strength, 

 and has proved to be the main factor in securing their durability. 

 Of course, some main walls in certain places show signs of bulging 

 out and of damage caused by earth-movements, possibly earth- 

 quakes, also by lightning, the sinking of foundations by water or 

 damp, or growth of trees within their open dr}' masonry during the 

 long period since their erection. Some faces of the walls shew a 

 complete swagging from end to end of their lengths, and vet the 

 batter back has jjreserved the walls perfectly intact throughout, Avith 

 each block still occupying its original relative position. The ap])ear- 

 ance of such walls strongly suggests the effects of earthquakes, and 

 while these earth-movements would destroy a plumb wall, a wall with 

 a severe batter-back such as is seen in all the oldest walls at Zim- 

 babwe would on this account be comparatively safe from such effects. 



In some instances the batter-back is ver\' severe, and exceeds 

 that of I foot in 6 feet, and the native labourers can climb such with 

 ease. Looking at the rounded extremities of any of the most 

 ancient walls, one notices that their sides resemble the lines of a 

 'lighthouse as popularly conceived, in many instances the batter-back 

 being more severe near the base and near the summit, and man\ of 

 such rounded ends of walls, where still perfect, show verv graceful 

 lines of battering. So carefully is the batter-back worked out in 

 the courses, that, looking up or down the face of a wall with one's 

 eye close to the blocks, one can scarcely see a quarter of an inch 

 of face of a protruding block out of the line of the battering. 



To secure the batter of the walls the blocks are not slanted 

 downwards at their inner side, but are laid on a true dead level, 

 reaching from inner to outer faces of the wall, and in their outer 

 courses their outside edges are placed back from the outer course 

 below. So slightl} do these courses recede one above another, !hat 

 in the height of only a few courses it would be almost impossible to 

 detect the presence of any battering, while it is very decidedly notice- 

 able in the height of some few feet. 



Mr. Bent's estimate of the extent of the battering of walls at 

 Zimbabwe, namely, i foot iiii 6 feet, is fairly exact with regard to 

 many walls, but excessi\e with regard to others, such as the main 

 walls of the Elliptical Temple, while for others now in a ruined state 

 it would appear to^ have been originally correct. The battering in 

 most instances being more perceptible near base and summit than 

 on the intermediate face of the wall (excepting the inside face of 

 the main wall in the Parallel Passage at the Elliptical Temple), and 



