On the Weald. 67 
came to the surface, and are now the common soil of the 
country. Inone place on the English side of the Channel 
(between Heathfield and Battle in Sussex) the Purbeck beds, 
which lie below the Hastings sand, are on the surface, but only 
to a very limited extent. The result of this movement was 
that the beds, instead of lying horizontally as they did before 
the upheaval, came to be domed along that part of the centre 
of the Weald which is now occupied by the Hastings sand, 
and were made to dip considerably to the N. S. E. and W. 
from that central line. 
The state of things which was thus brought into existence 
is well shown by a diagram, taken from Professor Ramsay’s 
“* Physical Geology and Geography of Great Britain” (page 
110), which represents what would have been seen if the 
dome had been complete. There is no reason, however, 
to believe that it ever was complete, but as the upheaval 
proceeded the strata were planed off, probably by the action 
of breakers in a shallow sea, and in this way they were 
made to assume on the surface the form of a series of 
‘concentric rings as they now appearon the map. A rather 
homely illustration will make this, perhaps, rather more clear 
to those of you who are not familiar with geological pheno- 
mena. By the process of upheaval, the beds, instead of being 
as they were before, flat, one on top of the other, came in the 
centre of the Weald to assume the form which is seen in any 
bulbous root which is made up of successive layers (as for 
example a Spanish onion) when looked at with the side up, 
and after the planing process of which I have spoken they 
become on the surface like the same root as it would be after 
the upper part was cut off, in concentric rings. Having thus 
been formed, the Weald district was at last raised above the 
sea and became dry land. There seems no room to doubt that 
the movement or series of movements which raised up the 
central part of the Weald also caused the formation of the 
English Channel. They probably lowered the strata in what 
is now the middle of the Channel, and thus enabled the sea to 
cut a channel through them instead of merely planing them 
off as it did on the English side. 
There is yet an important thing to be explained, the forma- 
tion of the hills and valleys which are found in the Weald. 
The Weald, when first raised above the sea in the way 
which I have described, would be a plain, flat, or very 
nearly flat, and made up as we have seen of strata lying 
in concentric rings. Outside of all is the hard Chalk, with 
the equally hard Upper Greensand below it; then comes the 
soft Gault, next the hard Lower Greensand, followed by the 
soft Weald Clay, and in the centre of all is the hard Hastings 
