96 RECENT EXCURSIONS OF THE
As to the remaining pollards, the great question is, Shall they be
re-pollarded? The reasons in favour of so doing are their drawn-up
character, owing to their having been left in an over-crowded state,
and the possibility of making them spread, and, a secondary reason,
pointed out by Sir Fowell Buxton, the variety of landscape colouring
obtained by the admixture of some of the dead leaves that hang on a
pollard with the young spring growth. The main argument against
the suggestion seems to be the danger of unauthorised lopping,
supplementing that undertaken by the Forest officials; but the
extensive felling of the last few years does not seem to have
produced such a result, and it might be possible to have, at least,
provisionally, some temporary enclosures for such an experiment in
management, similar to those already made for the purpose of
planting.
RECENT EXCURSIONS OF THE GEOLOGISTS'
ASSOCIATION IN ESSEX.
UPMINSTER AND HORNCHURCH.
ON March 5th there was an excursion for the purpose of visiting the cuttings
on the railway now being constructed between Upminster and Romford, a
northerly prolongation of that from Grays to Upminster. The first sections
inspected were those in the cutting west of Upminster Station, and east of the
Ingrebourne. They were seen to consist of London Clay, capped by a variable
thickness of gravel or loam, the former predominating. Here and there the
London Clay formed the surface for a few feet between two festoon-like beds of
gravel, a feature of frequent occurrence where the Clay is covered by these old
river deposits. The gravel of the high ground traversed by the railway between Up-
minster and Romford is of greater elevation and older date than that between Up-
minster and the Mardyke, the latter being only from 60 to 70 feet above Ordnance
Datum, while between Upminster and Romford the plateau is from about 90 feet to
a little over 100 feet. But, alike in each case, the surface gravel or loam is an old
river deposit, formed when the Thames flowed with a more northerly course and
at a higher level than it now does. Crossing the Ingrebourne the party entered
another cutting N.E. of the church at Hornchurch. There, in addition to
London Clay and old river-gravel, a hollow in the London Clay was seen to be
filled with Chalky Boulder Clay for a horizontal distance of about 300 yards, the
greatest thickness attained by the Boulder Clay being about 15 feet. It was to
view this Boulder Clay, which lies about three miles south of any hitherto known
in this district, that the excursion was planned so unusually early in the year;
and the party was fortunate enough to see a clear section of it close to its north-
westerly termination, the rest of the cutting having been sloped. Walking
thence towards Romford, cuttings on each side of the road at Butts Green were
inspected, that to the east showing only sand and gravel, while that between the