DISCOVERY OF THE PILTDOWN SKULL 299 
gravel, as soon as the floods had abated. . . ." Their 
labours were rewarded in the spring of 19 12 by the 
discovery of the greater part of a fossil human skull. 
We propose to follow Mr Dawson to the site of the 
gravel pit. Leaving Piltdown Common, we throw open 
the white gate which guards the private approach to 
Barkham Manor — an English farm-house rendered 
homely and picturesque by the passage of centuries. 
The avenue leads us straight to the farm-house ; the 
approach is flanked on either hand by a line of trees, 
which spring at regular distances from wide green 
margins, carpeted by Sussex turf. Here the farm carts 
come and go. Just before the house is reached the 
avenue of trees ends ; the road is then bounded by a 
hedge on the right and an open meadow on the left, 
which sweeps up to the hospitable doorway. If the 
visitor is not sharp-eyed he will miss the pit. It lies on 
the right hand between the roadway and the hedge — 
merely a narrow trench some 4 feet deep. Even to the 
professional eye it is a most unlikely spot to yield the 
remains of fossil man, and the bones of the animals 
which flourished in his time. 
The stratum of gravel is seen to be surprisingly shallow 
— rather less than 4 feet at this particular point. As the 
section of the side of the trench shows (fig. 97), the gravel 
rests on a bed-rock formed by one of the ancient Wealden 
rocks — the Hastings beds. The gravel is stratified — laid 
down by running water. The lowest or bottom layer, 
scarcely 6 inches in thickness, is the most important. 
The sand and gravel of this layer is cemented together by 
iron oxide ; everything embedded in the bottom layer is 
stained a deep brown from iron impregnation, washed out 
from ancient Wealden deposits.^ 
It was from this bottom or " dark " layer that Mr 
Dawson removed the right half of a peculiar human 
lower jaw. In the same stratum Dr Smith Woodward 
' In a recent publication Mr Dawson distinguishes a fourth unfossil- 
iferous stratum placed below the' bottom or dark layer, and above the 
Hastings beds, (luart. Jotirn. Geol. Soc.^ 1914, vol. Ixx. p. 82. 
