106 Primaeval Man in the Valley of the Lea.
part of the margin of the ancient Thames. If we imagine
water to be continuous over where London now is, at the 164
feet position near Baling a space of four miles is required
across the Thames to find the corresponding southern bank
at Richmond. This height would exactly reach the top of
the nave-roof of St. Paul's Cathedral, and nearly every
house in London would be under water. The 400 feet
position would only just leave the cross and ball of the
Cathedral out of the water. St. Paul's is 365 feet high, and
it stands about 65 feet above the Ordnance datum. It
follows therefore, from these figures, that since primaeval
man lived on the banks of the old, wide, shallow Thames,
the river has excavated its valley to a depth corresponding
with the height of the cathedral for many miles east and west
of London. The time required to excavate such a valley
must be enormous—at those remote times Hampstead and
Highgate (supposing for convenience that these places have
not since been lowered by denudation) could not have stood
higher above the shallow Thames than now do Homerton,
Clapton, and Leyton above the Lea. There are distinct
traces all round London of primaeval man's presence whilst
the Thames was excavating the valley from 164 feet down
to 50 feet above its present level.
When the 50 feet level is left, and a descent is made into
the valley of the river, the implementiferous deposits speedily
vanish; and this fact seems to indicate that, when these lower
gravels were deposited, Palaeolithic men were not present.
A magnificent view of one of the best of the Palaeolithic
terraces of the Lea may be seen from the neighbourhood of
Leyton Railway Station, or Temple Mills, near Stratford.
On looking westwards across the Lea, towards North London,
Hackney and Homerton can be seen on the left, and Stamford
Hill nearly two miles to the right. Homerton Church is 54
feet and Stamford Hill 107 feet above the Ordnance datum.
This is the best terrace in the Lea Valley; the whole two
miles from Victoria Park to Stamford Hill is one mass
of implementiferous Lea-gravel and sand, averaging 12 or 13
(but sometimes 20, or even 30) feet in thickness, and resting