106 PHnueval Mail 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 Ealing 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 
Higligate (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 18 
(but sometimes 20, or even 30) feet in thickness, and resting 
