between the arc and the intersecting circle measured on the
■same radius produced is equal to the diameter of one of the
towers.
The arc a k is built on a curve of 107-8 feet radius; and
i f 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 k b 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 12 9 | feet. These two lengths
of 107 and 1 2 9 | feet agree to within six inches with our actual
measurement of the wall itself.
I f 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
•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 o f 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.