HERTFORDSHIRE NATURAL HISTORY SOCIETY. IxY 
In places it was overlaid by Boulder Clay, and occasionally there 
were beds or seams of clay in it, and sometimes of brick-earth. It 
was largely composed of flints, and it also contained quartz-pebbles, 
quartzose sandstone, chalk, and fragments of older rocks. Occa¬ 
sionally Jurassic fossils were found in it, derived apparently from 
the Oxford Clay; and thick beds of sand often occurred in it. 
On leaving this pit, the east side of which is now grass-grown, 
obscuring the section, field-paths were taken across the gravelly 
land between the Mimram and the Lea. At Woodhall Wood, one 
mile south of Digs well Junction, the gravel passes underneath the 
Boulder Clay, which ranges eastward to Cole Green. The clay is 
one of a number of isolated patches lying south of the main mass, 
which, in the Biver Lea catchment-basin, terminates at its tributary 
the Beane. On the Chalk area the most southerly of these patches 
is at Bricket Wood; but there are others on the Tertiaries, still 
nearer to the northern edge of the Thames valley. 
At the Woodhall brickyard, which is a very extensive one, clay, 
sand, and gravel are dug. The pit shows the Mid-Glacial sands 
upwards of fifty feet thick, in a single vertical section, but a much 
less thickness of Boulder Clay than is seen at Bricket Wood. This 
gradually thins from one end of the pit to the other, probably from 
denudation, as it comes up to the edge of the pit, and the surface of 
the ground slopes to the south. It rests directly upon the Mid- 
Glacial sands, which pass down into coarse gravel, dug in places to 
the Chalk. It is this Boulder Clay which is used for brick-making. 
On leaving this pit the fields were crossed to Sherrard’s Park 
Wood, through which a path to Ayot was taken. Chalk has been 
dug in this wood for centuries, and it is believed to contain exten¬ 
sive underground galleries. Sections of the Beading Beds and the 
basement-bed of the London Clay exposed in the brickfield near 
Ayot station should now have been examined, but time did not 
permit, the train for Wheathampstead being due. On arrival there 
the members walked to Delaport, where they were hospitably 
entertained by Mr. and Mrs. IJpton Bobins, to whom the thanks 
of the Society were accorded, on the proposition of the President, 
seconded by Dr. Morison. 
After inspecting a gravel-pit in the grounds, the party separated, 
a few walking to St. Albans with the President, and the majority 
visiting the Church under the guidance of the Bev. Canon Davys, 
and leaving Wheathampstead by train. 
Pield Meeting, 30th May, 1891. 
CASSIOBTTRY PARK, WATFORD. 
The members assembled at the principal entrance to Cassiobury 
Park, and, some driving and others walking, crossed the park to 
the Swiss Cottage grounds, through which runs the river Gade. 
Some time was spent here in botanising, and then these grounds 
were left by the gate in Bousebam Lane, and the park was 
