By Alfred C. Pass. 247 
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ridge of chalk rock was allowed to remain, when all the rest was 
removed. This formed a causeway, and appears to have been the 
only way of approach to the hill from the adjacent high ground. 
Even between the end of this causeway and the hill, there was a 
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great gap of some depth. 
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The bottom of the deep trench, to the souti of the mound, has 
been considerably raised by infilling of earth washed from the 
turnpike road, which runs alongside it. This land belongs to 
another owner, so that I could not dig here; but I would suggest 
to the Wiltshire Archzological Society the desirability of sinking 
3 two or three shafts through the wash, down to the chalk, and thus 
_ to find the original depth of the trench here; and also to ascertain, 
by digging, whether the eastern causeway or projection forms any 
_ part of the original structure. I am inclined to think this may 
_ simply be composed of material deposited here, when the level of the 
_ turnpike road was lowered in the last century. This could easily 
be proved by ascertaining whether this projection is composed of 
solid chalk rock, or of loose material which has been brought here. 
A little below the top of the hill, and nearly surrounding it, is 
a ledge or terrace. This may be either a part of the original design, 
and may have formed the base of a stockade or defence of some kind ; 
or it may have been formed by the slipping down of the outside 
materials of the hill. This point deserves examination.  Fer- 
gusson, in “Rude Stone Monuments,” says :—‘ Nothing would 
surprise me less than if five or six entombments were found arranged 
around the upper plateau, at a small depth below the surface.” 
_ The mystery of its origin; Who built it? For what purpose? 
W hen? were questions which vividly presented themselves to me 
the first time I visited Silbury Hill, some years ago, on a lovely 
iant day in June. When looking down from the summit of 
this great mound, I was struck by the well-defined line, plainly 
marking out the limit of the space, from whence the materials had 
been excavated for making the hill. This area is below the level of 
the adjacent ground, and the grass grows there of a brighter green, 
pei haps owing to a greater amount of moisture in the soil. Since 
then, it occurred to me that an excavation in this meadow at the 
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