(FIGURE 39. MAP OF THE BRITISH ISLES AND PART OF THE NORTH-WEST
OF EUROPE, SHOWING THE GREAT AMOUNT OF SUPPOSED SUBMERGENCE
OF LAND BENEATH THE SEA DURING PART OF THE GLACIAL PERIOD.
The submergence of Scotland is to the extent of 2000 feet,
and of other parts of the British Isles, 1300.
In the map, the dark shade expresses the land which alone
remained above water. The area shaded by diagonal lines is
that which cannot be shown to have been under water at the
period of floating ice by the evidence of erratics, or by
marine shells of northern species. How far the several parts
of the submerged area were simultaneously or successively laid
under water, in the course of the glacial period, cannot, in
the present state of our knowledge, be determined.)
(FIGURE 40. MAP SHOWING WHAT PARTS OF THE BRITISH ISLANDS
WOULD REMAIN ABOVE WATER AFTER A SUBSIDENCE OF THE AREA
TO THE EXTENT OF 600 FEET.
The authorities to whom I am indebted for the information
contained in this map are—for:
SCOTLAND:
A. Geikie, Esquire, F.G.S., and T.F. Jamieson, Esquire,
of Ellon, Aberdeenshire.
ENGLAND:
For the counties of:
Yorkshire, Lancashire, and Durham: Colonel Sir Henry James, R.E.
Dorsetshire, Hampshire, and Isle of Wight: H.W. Bristow, Esquire.
Gloucestershire, Somersetshire, and part of Devon: R. Etheridge,
Esquire.
Kent and Sussex: Frederick Drew, Esquire.
Isle of Man: W. Whitaker, Esquire.
IRELAND:
Reduced from a contour map constructed by Lieutenant Larcom,
R.E., in 1837, for the Railway Commissioners.)
(FIGURE 41. MAP OF PART OF THE NORTH-WEST OF EUROPE, INCLUDING
THE BRITISH ISLES, SHOWING THE EXTENT OF SEA WHICH WOULD BECOME
LAND IF THERE WERE A GENERAL RISE OF THE AREA TO THE EXTENT
OF 600 FEET.
The darker shade expresses what is now land, the lighter shade
the space intervening between the present coastline and the
100 fathom line, which would be converted by such a movement
into land.
The original of this map will be found in Sir H. de la Beche's
"Theoretical Researches" page 190, 1834, but several important
corrections have been introduced into it from recently
published Admiralty Surveys, especially:
1st. A deep channel passing from the North Sea into the
entrance of the Baltic.
2nd. The more limited westerly extension of the West Coast
of Ireland.)
The late Mr. Trimmer, before referred to, has endeavoured to assist our speculations as to the successive revolutions in physical geography, through which the British Islands have passed since the commencement of the glacial period, by four "sketch maps" as he termed them, in the first of which he gave an ideal restoration of the original Continental period, called by him the first elephantine period, or that of the forest of Cromer, before described. He was not aware that the prevailing elephant of that era (E. meridionalis) was distinct from the mammoth. At this era he conceived Ireland and England to have been united with each other and with France, but much of the area represented as land in the map, Figure 41, was supposed to be under water. His second map, of the great submergence of the glacial period, was not essentially different from our map, Figure 39. His third map expressed a period of partial re-elevation, when Ireland was reunited to Scotland and the north of England; but England still separated from France. This restoration appears to me to rest on insufficient data, being constructed to suit the supposed area over which the gigantic Irish deer, or Megaceros, migrated from east to west, also to explain an assumed submergence of the district called the Weald, in the south-east of England, which had remained land during the grand glacial submergence.