lxii 
PROCEEDINGS. 
northern Middlesex were formerly the meeting-ground of old 
streams from the north through the Stevenage gap, from the west 
through the Goring gap, and from the south ; these uniting to form 
an easterly-flowing stream across Essex. The main river probably 
flowed southward before the existing low-lying ground of Bedford¬ 
shire had been excavated, and it brought fragments from rocks far 
to the north. 
At Burnham Green, near the Duck Inn, some large boulders of 
Sarsen Stone and of Herts conglomerate were seen, and then, after 
passing Datchworth Church, a large pit, known as Holten’s, was 
visited. This is upwards of ten feet in depth, and shows lines of 
stratification very distinctly, except where it is disturbed owing to 
irregular dissolution of the Chalk on which it rests. This gravel 
consists chiefly of Tertiary flint-pebbles, some of which are green- 
coated, Herts conglomerate, Bunter quartzites, quartz, and sand¬ 
stone. Two unworn flints over a foot square were seen, and also 
frequent sandy and clayey patches. This gravel is lower in 
position and of more recent formation than that first visited, and 
differs from it in containing much Triassic material. 
Returning to Welwyn Station, tea was provided at the Cowper 
Arms, and a vote of thanks was accorded to Dr. Salter for his 
exposition of the geology of the district. Most of the geological 
information in this report is derived from his account in the 
1 Proceedings of the Geologists’ Association’ (vol. xix, p. 108). 
Eield Meeting, 15th April, 1905. 
FLITWICK AND SILSOE. 
This field meeting, like the last, was held in conjunction with 
the Geologists’ Association. Mr. Hopkinson, and Mr. Saunders of 
Luton, acted as Directors for both Societies. 
In the journey north, on the Midland Railway, the Upper 
Cretaceous strata were passed through, and in the cuttings between 
Chiltern Green and Charlton the three hard beds in the Chalk— 
the Chalk Rock, the Melbourn Rock, and the Totternhoe Stone— 
Avere seen. On the plain beyond, the Gault was traversed, and in 
approaching Flit wick the outcrop of a formation better withstanding 
denudation — the Lower Greensand — became evident from the 
rising ground. The Chalk on the south, attaining a height of 
800 feet, and the LoAver Greensand passing through the centre of 
Bedfordshire, rising to 500 feet, form the two main ranges of hills 
in the county, and the object of this meeting was to examine 
sections of the latter formation. 
The party assembled at Flitwick Station at about half past 3. 
A good section of the Woburn Sand, with its variously-coloured 
beds, from white to red, was seen in a pit near the railway, on the 
west of the line, its position appearing to be about the middle of 
