42 
HOW SCENERY IS MADE. 
III. — Origin of Clay-Rocks. 
E must now consider what the sea can do. Every one 
has noticed how the waves beat against the cliffs at 
high water, and especially in stormy weather in winter, 
when huge masses of rock frequently fall down, being 
undermined below, and aided by water freezing in the cracks 
and so thrusting them outwards. 
Paths running along the edges of sea-cliffs have again and 
again to be made further inland, as, for examples, along the 
Chalk cliffs at Margate, and the London Clay cliffs at Felix- 
stowe ; so that houses, &c., once far inland, find themselves in 
danger of perishing. The church at Reculver in Kent, and 
that of Eccles in Norfolk, are good examples ; for manj' years 
the tower alone of the latter stood on the beach. Similarly at 
Cromer, a new light-house had to be built farther away from the 
edge of the cliff. 
In some cases, as with the chalk cliffs on the south coast, 
there is an underlying sloping bed of clay, and when much 
water has reached it, the chalk cliffs slide down it causing great 
landslips. The materials are thus brought within the action of 
the waves, which in a few seasons may clear them all away. 
What becomes of all the solid substance of many miles of 
land thus destroyed and swept away in course of time ? The 
harder portions fall and remain to form the beach pebbles, and 
the finer sand comes next. If the cliffs be of chalk, this is 
dissolved, but the finer particles of clay are carried out to sea, 
suspended in the water, till, at last, they finally settle down to 
form a sea bottom of clay. 
Several of these clay sea-beds have become dry land again 
in the course of ages, and in consequence of their upheaval. 
Thus the great valley of the Severn between the Cotswold and 
the Malvern hills mainly consists of the Lias clay abounding 
in marine fossils, shells, &c. Another called Kimeridge clay 
occurs near Swanage. Cambridge stands on a third known as 
the Gault, the same clay bed which underlies the Chalk at 
Folkestone and causes the landslips in that neighbourhood. 
The London Clay forms a great triangle : the coast line from 
Aldborough to Deal is one side, the other two meet at New- 
bury. A portion of this was deposited in an estuary, as tropical 
fruits, like those of modern estuarine screw- pines, together with 
turtles, &c., are found in the clay of the Isle of Sheppey. 
The Wealden clay beds of central Sussex were in part 
estuarine ; but the great “ glacial ” drifts of East Anglia, which 
are mainly composed of clay, had better be considered as a result 
of ice-action. 
Clay being soft is, of course, easily removed by running 
water ; consequently, however flat the bed might have been 
