XV111 
PROCEEDINGS, 
which forms the base of the Middle Chalk. On the summit of the 
hills behind them were the lower beds of the Upper Chalk, and for 
some miles along the Dunstable Downs, as far as the Dive Knolls, 
four of which were distinctly visible, the Chalk Dock could be 
traced a little below the highest ground, its presence being 
indicated just beyond the upward termination of the steep face 
of the escarpment, nearly on level ground, by a slight ridge due to 
its hardness. Beyond the Five Knolls would be seen Totternlioe 
Castle Hill, an outlier of the Melbourne Bock forming its summit, 
dust round the extreme point of the hill were the Totternlioe 
quarries, where the Lower Chalk is now quarried for lime-burning, 
but the Totternlioe Stone at the base of the hill, for which the 
quarries were originally opened, is not now quarried as a building- 
stone. The position of the Melbourne Bock between Totternhoe 
Knoll and Ivinglioe Beacon could not easily be traced, as it does not 
form a distinct feature in the landscape ; but there was no difficulty 
in determining where the Totternhoe Stone occurred, for each little 
valley or coombe seen at frequent intervals all along the foot of the 
Downs ended at its base, these valleys in some cases, but not in all, 
originating in a spring, owing to the water percolating through the 
Totternhoe Stone and being thrown out by the comparatively 
impervious Chalk Marl below it. This, he said, extended for some 
distance from the base of the escarpment, its surface being almost 
horizontal, and its dip where it is exposed being less than when 
it passes under the great mass of the Chalk. 
Pointing out Eddlesborough Church on an isolated hill, the 
Director said that that hill was an outlier of the Totternhoe Stone 
on the Chalk Marl. The next village beyond was Eaton Bray, 
where a thin band of the Upper Greensand appeared, and at a little 
greater distance in the same direction Billington Hill with its 
church could be seen, that being on an outlier of the Lower Chalk 
over the Gault, of which the greater part of the plain below them 
consisted. Beyond this, again, the picturesque and well-wooded 
ridge of the Lower Greensand formed the horizon on the north 
from Leighton Buzzard for some distance across Bedfordshire 
towards Sandy and Potton. On the left, to the south-east, the 
Tring reservoirs, which supply the Grand Junction Canal, were 
seen, the farthest being on the Gault and the other three on the 
Chari Marl. 
A reference to Mr. Whitaker’s paper on Subaerial Denudation 
was then made, and his arguments in favour of the Chalk escarp¬ 
ment being the result of such denudation and not a sea-cliff were 
adduced. A view of an isolated terraced hill between the Downs 
and Eddlesborough, rising in a shallow valley which was traced up 
to a deep coombe, afforded an opportunity to broach a theory that 
some lynchets, at least, as these terraces are called, may be the 
remains of one side of a coombe, the terraces on each being- 
remark ably sim ilar. 
On descending the hill a coombe just below it was examined, 
and its remarkably flat bottom, and regular, clear-cut, side terraces, 
