272 THE ESSEX NATURALIST.
3. As regards the direction and rate of movement of the land surface
of the island, the evidence afforded by excavation is, so far as it goes,
in agreement with the Neolithic, Roman, and Geodetic evidence relating
to the Thames Estuary,5 and indicates that subsidence has occurred
at the average rate of about nine inches per 100 years. The absence of
forest deposits and pent in the subsoil of the island, other than those
found deeply buried (30 to 40 ft.) in the shore at Leigh Beck Marsh,
indicates that the land movement has proceeded in one direction only—
viz. downwards—for many years preceding the occupation of the sites.
The possibility that some of the subsidence that has occurred in the
island may be due to sub-aqueous sliding of upper strata, carried on
water-saturated silt, towards the bed of the river, is not excluded.
Independent evidence of the correctness of the subsidence rate given
above is afforded by a study of the flora of the saltings, the nature of the
plant remains in the subsoil there, and the rate of deposition of silt on the
saltings surface at times of spring-tide.
The banks thrown up by tidal action afford necessary protection to
plant life on the marshes, and the plant life reciprocally helps to determine
the level of the marshes when these arc afforded opportunity to mature.
THE ESSEX FIELD CLUB—REPORTS OF
MEETINGS.
RAMBLE IN HAINAULT FOREST (804th MEETING).
SATURDAY, 1ST APRIL, 1939.
A very small party of members met at Chigwell Row at 2.45 o'clock
for an early Spring ramble through th? woodlands of Hainault Forest:
perhaps the date chosen, suggesting the possibility of a practical joke,
induced prudent persons from attending, as only fifteen in all were present.
Even the Hon. Excursions Secretary himself, who had arranged the
meeting, failed to appear, but he had the sufficient excuse to offer of an
attack of influenza: and our new President, Mr. S. Hazzledine Warren,
was one of the small gathering.
The Forest was entered from the road leading to Hog Hill, and here
Mr. Thompson, who acted as deputy guide in the absence of Mr. Salmon,
gave a short account of the history of Hainault from its disafforestation
by Act of Parliament in 1851, when it comprised 17,450 acres, of which
some 4,000 acres were open and unenclosed waste, to its re-birth in
1903, when, at a total cost of £21,830, of which the London County Council
contributed £10,000, it was placed under the care of that body to be
maintained as a public open space, and in July, 1906, dedicated to the
public use. Today the Forest includes soma 800 acres of charmingly
diversified woodland and rolling downs, the latter sprinkled with clumps
of trees and bushes which, planted before 1906, have now assumed a
5 Capt. T. E. Longfield. "Subsidence of London," Ord. Surv. Prof. Papers, New Series,
No. 14 (1932).