MR. J. T. HOTBLACK ON THE NORWICH CASTLE MOUND. 339 
during the progress of the recent cutting away of the hill, and 
these plainly show that for some feet above the present ground 
level there is sand and gravel which has never been disturbed 
since it was deposited in some comparatively remote geological 
period. The height of this undisturbed ground was found by 
comparing the sketches taken at different times, to rise as the 
mound was entered, and it may be reasonably expected that 
further into the mound the natural ground would be found 
higher still. The builders have not been content with cutting 
away the face of the mound, but they have gone down some 
ten feet deeper than the ground level, and this cutting shows 
the undisturbed chalk, with many large flints, but just below 
the ground level ; and, again, I should not be surprised if the 
undisturbed chalk itself rises higher further into the mound. 
On the other hand trial holes sunk only a few feet from the 
base of the mound show 20 feet of black soil, and even at 
20 feet they have not reached the bottom of it. 
The accompanying photograph taken a day or two before 
the cutting away was completed, shows by the ladder of 
30 staves, 9 inches apart, that the depth of the cutting was then 
about 20 feet ; but when I last saw it. just before the concrete 
wall was commenced, the same ladder hardly reached the 
top, so that the cutting would then be at least 23 feet. Of 
this, on an average, quite 12 feet was undisturbed sand and 
gravel ; in one place it might be as high as 15 feet, and in 
another as low as 9 feet ; above this came an average of 8 feet 
of black soil, this again varied a good deal, being thicker 
where the sand and gravel were low, and thin where they 
were high ; above this came a very level band of about 
two feet of white chalk, and above that again about one foot 
of black soil. It looks as though the excavators of the ditch 
first threw the black soil from the surface on to the top of 
the cliff, then when t they came to the chalk in the bottom of 
the. ditch, that was thrown on the top of the black soil, so that 
the hill when first raised would be as it were encased in chalk. 
The thin layer of black soil on the top of the chalk I take to 
have been formed there since the mound was raised. 
One word more as to the unwisdom of these operations. 
