IN THE VALLEY OF TI1E GADE. 
255 
flinty loam passes into a dark-brown clay, containing unworn flints, 
and resembling tbe typical clay-with-flints so closely that it may 
be rightly regarded as a local deposit of clay-with-flints, occurring 
at a lower level than usual. The determination of the nature of 
the beds of loam was rendered difficult by the occurrence therein 
of two extraordinary deposits of chalk-rubble of variable com¬ 
position, and consisting mainly of disintegrated chalk, flints, and 
loam, confusedly mixed together. One of these deposits rested on 
the Chalk for a long distance, and then extended like a tongue into 
the loam, so as to separate the lower loam from the upper; the 
other deposit of chalk-rubble lay within the loam. The existence, 
in the line of excavations, of two deposits of chalk-rubble which 
thinned off towards each other, as shown in Fig. 27, admits of no 
doubt, for one pit was sunk without meeting with any chalk- 
rubble, while the next pit to the north, and also the next pit to the 
south, passed through that material, the only difference being that 
the rubble in the southern was deeper than that in the northern pit. 
The soil and subsoil were each about one foot thick at the 
northern end of the excavations; elsewhere they were very thin. 
The thinness of the soil and subsoil over the parts where the 
chalk-rubble occurs, the nature of the chalk-rubble itself, and the 
fact that much of the chalk debris from the Watford tunnels was 
deposited at various places between the tunnels and King’s Langley 
Station, might suggest that the chalk-rubble and the beds above it 
are made ground. This would be an easy way of accounting for 
the occurrence of so puzzling a set of beds. The way in which 
the chalk-rubble lies immediately in contact with the Chalk in one 
part of the excavations and in the loam in the other part, and the 
fact that no remains of an ancient soil were met with beneath the 
rubble, make it difficult, however, to believe that the formation of 
the rubble and the beds above it was not due to natural causes. 
Mr. Webb also assured me that he found no indication of made 
ground in this part of the excavations. Beyond the southern end 
the ballast thinned out, and gave place to a carbonaceous bed, 
which passed into an extensive peat bed near the Gasworks. 
Another peat bed was found in the excavation at the Sewage 
Pumping Station at Hunton Bridge. This bed was 4 feet thick 
in one part, but thinned out very rapidly. Beneath the thickest 
part of the peat was a bed of ballast, and in a few parts of the 
excavation the ballast was covered by a bed of light-grey clay. 
These peat beds were described to me by Mr. W'ebb. A third 
carbonaceous bed was found opposite and near the “ King's Head,” 
Hunton Bridge, and is represented in Fig. 28. The beds exposed 
were:—1, made ground, about 3 ft.; 2, gravel and sand, about 
1 ft. 6 ins.; 3, carbonaceous clay, with remains of wood, leaves, 
end fresh-water shells, 1 ft. 9 ins. ; 4, light-grey clay, 1 ft. ; 
5, clean ballast, 1 ft. All the shells were very much broken. 
In the excavations in Hunton Bridge Boad, the Chalk was 
covered in the higher parts of the road by clay-with-flints, loam, 
and gravel and sand. In the Upper Highway the excavations were 
