322 
Superficial Gravels and Clays . 
[July. 
side of Finchley Lane. The Upper Clay, with its accom- 
panying patches of gravel, is thin, but it is seen to be conti- 
nuous nearly to the brook. On the north side of the lane, 
Fiji. 8 . 
Section in Bank oe Brook below the Hendon Lane Bridge. 
a, i. Brown unstratified clay. A, 2 . Coarse pebble gravel. L. London Clay. 
along the line of section, it has been dug in several places ; 
in others the clay has been denuded by natural agencies, and 
the coarse pebble gravel that lies at its base comes to the 
surface. The Middle Sands and Gravels come in below the 
clay at about the same height as on the Finchley side of 
the brook — that is, at about 200 feet above the Ordnance 
datum-line.* A little above that level, at the point marked i 
in general section (Fig. 1). I saw some sandy subangular 
gravel that had been thrown out in digging the foundation 
for a house. I have not seen anywhere on the Hendon slope 
these beds so strongly developed as they are on the opposite 
side of the brook, but Mr. Henry Hicks has informed me 
that near Heriot House they were 30 feet in thickness. 
Ascending the hill towards St. Mary’s Church, the Upper 
Glacial Clay is seen in every road cutting and in excava- 
tions for new houses ; but I did not see any deep enough to 
expose the sands or gravels until near the summit of the 
hill, where sand below the clay has been dug in several 
places, but the sections were not good enough for me to 
determine whether it belonged to the Middle Glacial beds 
or not. 
On the west side of Hendon, down as far as the Midland 
Railway, the Upper Clay is everywhere present. To the 
south it is also seen wherever there are cuttings, but the 
Middle Sands and Gravels are not exposed, and I think they 
are mostly absent. To the northward the Chalky Boulder- 
clay is continuous from Finchley along the ridge past 
Whetstone. By the side of Church Lane, in Whetstone, 
the Middle Sands and Gravel are worked. I obtained here 
the section shown in Fig. 9. The surface of the ground is 
at this place about 290 feet above the Ordnance datum-line. 
Mr. Caleb Evans has noticed the occurrence of the 
* The Ordnance datum-line is the mean level of the sea at Liverpool. 
