OF THE COUNTY OF SUSSEX. 
3 
From this circumstance, a considerable difference 
exists in the "eolomcal relations of the eastern and 
O O 
western divisions of the county ; the latter being 
characterised by a range of chalk liills in the centre, 
with a maritime district formed of clay and gravel 
on the south, and a weald composed of sand and 
clay on the nortli. 
Throughout its whole extent this chain exhibits 
decisive manifestations of the action of water. Not 
only are the ridges and summits of the hills rounded 
and even, but their surface is every wliere furrowed 
by coombes, or narrow undulating ravines : these, 
uniting, terminate in valleys, that intersect the 
downs in a direction nearly north and south, and 
form extensive outlets for the rivers that flow from 
the interior of the country into the British Channel. 
The course of the smaller excavations or coombes 
is exceedingly various, but their general bearing is 
east and west ; they gradually increase in breadth 
as they descend, and their opposite sides have cor- 
responding angles and sinuosities : this appearance, 
liowever, is not observable in the principal valleys. 
The chalk hills of Sussex are separated into five 
distinct masses, by the following rivers ; viz. the 
Arun, the Achir, the Ouse^ and the Cuckmere. 
The first is situated in AVestern Sussex : it rises 
in the forest of St. Leonard, near Horsham, and, 
taking its course to the westward for a few miles, 
turns suddenly to the south, passes through the 
chalk near Arundel, and falls into the sea to the 
west of Little Hampton. 
The Adur constitutes the western boundary 
of the South Downs, properly so called : like the 
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