PRIMAEVAL MAN IN THE VALLEY OF THE LEA. 133
good and obvious reasons for keeping within a moderate distance of
the streams.
The "Palaeolithic Floor" on the Essex side of the Lea has been,
to a very great extent, pushed away by the advancing "warp and
trail," or denuded away since Palaeolithic times. At present I have
only seen it on the east side of Leyton Street, and near "Walnut
Tree House." On the Middlesex side of the Lea the "floor" is of
great extent. I have seen it at London Fields, and south of and at
Kingsland, and it exists in some parts of Fleet Street, Drury Lane,
Gray's Inn Lane, and Clerkenwell, at about seventy feet above the
Ordnance datum. It is well seen at Highbury, whence the first
implement was obtained by Mr. Norman Evans; at Shacklewell,
South Hornsey, some parts of Abney Park Cemetery, and Stoke New-
ington Common. I, however, have seen traces of it on many other
surrounding places, and I believe, in short, it extended over the whole
of East Middlesex by the Lea, into Herts as far as Hertford, Ware,
and Wheathampstead, and on both sides of the Thames from London
to the Nore.
It is a curious fact that the superimposed "warp and trail" is also
implementiferous; the implements in this material are all more or
less abraded, some very much so, and many are whitish or mottled in
colour from long contact with the tenacious clay, and these latter
implements have been brought from the north, from the lower gravels
in the neighbourhood of Amwell, Ware, Hertford, Bush Hill Park,
and Forty Hill, Enfield, and deposited at North-east London, over
the Palaeolithic Floor. At Ealing Dean certain of the implements
have been carried down into the valley from the heights to the north
of 164 feet.
When the Shacklewell gravel was originally referred to by Mr. John
Evans ("Ancient Stone Implements," p. 523), he wrote that it rested
on the slopes of the Hackney Brook, and from the knowledge of its
position to be obtained at that time, he was quite justified in the
supposition. When I first found implements in the sand close to this
brook, I too thought that the implements really belonged to its
valley. But when at last the brook was quite obliterated and builders
dug foundations for houses in the middle of its bed, it was clear that
the brook had nothing whatever to do with the Lea and Thames
gravel at this place, but had merely excavated its way through it. On
a section being made through the brook, the "Palaeolithic Floor"
was seen in section on both sides as at E, fig. 14. I have seen a