The arc AK is built on a curve of 107·8 feet radius; and if a circle be drawn as described with a radius of 169·3 feet, it will determine the length of the chord of the arc at 107 feet, and the distance between the two arcs measured on the middle radius will be 5·45, which is equal to the diameter of the little tower.
The arc KB treated in the same way, with a curve of 84·6 feet, and with a distance of 17·17 feet (the diameter of the great tower) between the intersecting circle and the arc, has the length of its chord fixed at 129½ feet. These two lengths of 107 and 129½ feet agree to within six inches with our actual measurement of the wall itself.
If we apply our system to the arc BC in an exactly similar manner, but with the distance between the circle and the arc made equal to the radius of the great tower, we find that the length of its chord should be 111 feet; and this also agrees closely with our measurements.
The arc of the eastern temple on the hill has a radius of 42·3 feet, and if a circle of 169·3 feet be applied to it with a distance of 17·17 feet between the circle and the arc, we find that the length of its chord should be 72 feet; and this is exactly what we make it on our plan. This also explains the hitherto inexplicable position of the eastern doorway.
In a similar way we determine the length of the chord of the great wall in the western temple to be 140 feet; but as the [[404]]ends of this wall are in a ruinous condition, and as the present outer face is not of the original period, we cannot say whether this was the actual measurement or not.
With two exceptions, there are no other arcs which are sufficiently complete to allow us to ascertain their original measurements. These exceptions are the arc in the little temple at G, and that from the doorway to A. In the former case, the length of the arc is fixed by the two doorways; and as one of these is placed north of the centre in order to permit of observation along the meridian line, and the other is made to serve the same purpose for the line GW, it is obvious why the length of this arc was not determined in the same way. In the latter case, as one end of the arc is at a northern doorway, and as we are not quite certain of the length of the radius of the arc itself, we have not attempted to determine the length of its chord.
It is much to be desired that more of the plan of the original temple should be recovered, and this can only be done by careful excavation conducted by some one of experience in the art; for an inexperienced or careless workman could easily and unwittingly remove any of the remaining mortarless foundations without ever discovering that he had done so. [[405]]
APPENDIX D.
The following notes have been kindly supplied by the Secretary of the British South Africa Company:—