1870.| cODRINGTON—-HAMPSHIRE AND ISLE-OF-WIGHT GRAVELS. 547 
streams haye*. It is difficult to conceive that a river flowing with 
the velocity due to such a fall could have spread out the gravel over 
these wide even surfaces more than 20 miles across ; and the various 
directions in which the tablelands slope forbid the supposition that 
any part of the present inclination is owing to a subsequent tilting 
up of the land. 
It is perhaps a more probable hypothesis that the spreading out of 
the gravel and the levelling of the plains took place in an inlet shut 
in on the south by high land and opening out to the eastward. If 
this were the case, the land at the time of the deposition of the 
highest gravels now remaining must have stood 420 feet lower ; and 
this may have been in some degree contemporaneous with the great 
depression of the Boulder-clay epoch. A deposit thus formed of ma- 
terials brought down from the chalk country on all sides would be 
entirely local in character ; but the apparent absence of indications 
of glacial conditions in the gravel, except at levels so low as to cor- 
respond with valley-gravels, is not easy of explanation. 
(d) The raised shingle of the Foreland, the marine gravel of the 
south of Sussex, and the beach-deposits with sea shells at Avisford 
and Waterbeach are evidences that at a time geologically recent the 
land stood 80 or 100 feet lower. Flint implements, however, are 
found imbedded in gravel 120 feet above the sea on the Bourne- 
mouth cliffs, and 150 feet above the sea on Southampton Common ; 
and an hypothesis which assumes that man existed when gravels, 
now 120 and 150 feet above the sea, were forming at or below 
the sea-level may be on that account alone considered as untenable. 
But flint implements are found at Menchecourt associated with marine 
shells at 40 feet above the sea, and at the Foreland under circum- 
stances which seem to show that an elevation of land to the extent 
of from 70 or 80 feet has taken place since man’s appearance; and 
when it is considered what an enormous amount of change has taken 
place at Salisbury and elsewhere since the high-level gravels con- 
taining flint implements were deposited, and what a vast amount of 
time: such changes imply, it does not appear to be incredible that 
the upheaval should have been so much as 150 feet. 
A considerable alteration in the coast-line must also have taken 
place. Land must have existed to the south of an inlet such as that 
supposed, of which the Isle of Wight is but the shadow. Denudation 
of the surface by subaérial action, and of the coast by the sea, must 
have gone on pari passw with upheaval ever since the high plains 
were first raised above the sea-level. As the land gradually rose, 
the effect would have been to contract the inlet and bring it into 
the condition of an estuary branching into the Solent and South- 
ampton Water. Of these, the latter remains an estuary, while the 
* Fall of the Rhine. Source to Dissentis ............ 60 feet per mile. 
3 Dissentis to Constance......... 16 5 
ty Rhone. Source to Brieg..............0068 52 sl 
3 Brieg to Lake of Geneva ...... 10 i 
is Clyde. Source to Lanark ..........,.... 20 
