Primaeval Man in the Valley of the Lea. 109 
America, and northwards towards Iceland. At this period of 
time Clapton and Homerton on one side and Leyton and 
Stratford on the other were the points where the Lea poured 
itself into the Thames. The great width of the stream in 
Palaeolithic times is proved by the presence of the gravel- 
terraces ; that these terraces were really the old river-margins 
(now sometimes a mile or even four miles from the stream) 
is proved by the abundance of fossil shells of land and fresh¬ 
water molluscs contained in them. 
In fig. 1 I have engraved a small portion of North-east 
London, including Tottenham, Stamford Hill, Walthamstow, 
Woodford, Snaresbrook, and Barking Side. The dotted 
portion shows the disposition of the gravels, and their 
positions in regard to the Lea and Boding. No doubt the 
gravel banks were at one time continuous, and so prevented 
the river from overflowing the country, but centuries of 
denudation have now removed part of the gravel. The Plan 
is engraved to a scale of one inch to a mile, and at fig. 2 is a 
section of the ground to the same scale ; the vertical scale 
being 800 feet to one inch. The solid black portions on the 
tops of the elevations show the implement-bearing gravels, 
and the black below the sea-level line is the gravel beneath 
the Lea and Boding. The figures indicate the heights above 
the Ordnance datum or mean sea-level, b represents the 
London-clay on which the gravels rest; c, the Woolwich and 
Beading beds ; d, Thanet sand ; e, Chalk ; f, Upper Green 
sand; g, Gault. Beneath the general section are two other 
sections,—figs. 8 and 4, through the rivers Lea and Boding, 
—showing the gravels contiguous to and under the streams. 
These are drawn to a horizontal scale of three inches to the 
mile, and a vertical scale of 320 feet to an inch, to more 
clearly show the gravels as they rest on the London-clay. 
The plan and sections are founded, by permission of Mr. 
William Whitaker, on the admirable geological Model of 
London in the Museum of Practical Geology in Jermyn Street. 
The enormous power of the ancient Lea and Thames during - 
flood-times is proved by the huge masses of sandstone fre¬ 
quently met with in the gravel. I measured a block last 
