1879*] Ancient Observatory at Delhi. 783 
Each of these divisions represent 100 minutes of horizontal 
angle. 
Having completed* as well as time permitted, our mea- 
sures of the towers, we devoted our spare time on the 
second day to a closer inspection of the great Sun-dial. 
It is built on the edge of a natural, or perhaps artificial, 
depression in the ground, so that, though it only stands 
some 60 feet above the general level of the country, its per- 
pendicular face really has a front of about 9a feet, the 
excavation at its foot giving it that additional height. From 
each side of its foot, and (in plan) at rather less than a right 
angle, sweep up the great arcs on which the shadow falls. 
The Western one is quite ruined : a large badger appeared 
its only tenant, and watched us. The Eastern one had 
enough remaining to enable us to follow the shadow over 
the few existing legible markings, by mounting a very nar- 
row and hazardous flight of steps which followed the sweep 
of the arc. As I mounted the ruined steps, spare remnants 
of the “ ivory ” cement called my attention, and it was clear 
that the crest of the parapet between me and the gnomon 
was the dial on which the time was marked. 
Waiting till the sun was low I was able to watch the 
shadow moving over some of the more perfect portions of 
the scale. The workmanship was kindred to that of the 
towers— brickwork, rough plaster, finer plaster, and for the 
inscribed portions the “ ivory ” cement. I was not able to* 
measure the angular divisions of the circle on this arc, but 
I could see the markings were finer than could be read, or, 
in other words, the penumbra on the edge of the shadow 
was wider than the space between each of the finer marks, 
so that its fall on each could not be noted accurately by my 
unpractised eye. These smallest divisions were arranged in 
groups of five. A blank concentric space of the same 
angular value marked each block of five, and an inner curve 
again gave larger divisions, but there was no portion of 
plaster left large enough to count how the enumeration was 
commenced. 
An eye accustomed to watch the record of this great dial 
could no doubt read it to a fraction of a minute ; but with 
such a broad penumbra no two observers could, I think, 
give similar independent readings. 
On our two visits to the top of the gnomon we took fre- 
quent measures of its angle ; they all lay between — 
28° 15' and 28° 45' (mean 28° 30'), 
or close on the real latitude of the spot. 
