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GLACIAL GEOLOGY OF GREAT BRITAIN

higher in proportion then, as they are now. Indeed, in oldtimes there was more disproportion in the elevation of rivervalleys than there is now. I mean the difference betweenthe upper and the lower parts of their beds was greaterthen, and must have been so, for erosion is always cuttingdown the upper, and filling up the lower parts. I meanthat just as the beds of rivers at their mouths werevery much deeper than now (buried rivers), so theirupland portion was very much higher than it is now.

To represent it diagrammatically, I take the DelawareBiver as it is and as it was :—]

Fig. 48.—Diagram showing different Levels of the Ancient and Present Beds of theDelaware River .

H. Miller, Biver Terracing. Royal Phys. Soc., 1883,p. 263. Admirable paper on the subject, reviewing all thetheories.

H. Miller, On Boulder Glaciation. Good striatedpavements. Glaciated about Edinburgh . Fluxion structurein till. Royal Phys. Soc. viii. 157.

H. Miller, Tyndale Escarpments. Nat. Hist. Trans.,North Durham and Newcastle-on-Tyne , vii., 1880. Good.

Slight erosive power of glaciers. Quote. Snailboringsdue to weathering and snails, not pholas. Glaciers havefailed to hold escarpments.

Supposed submergence of Great Britain during the Glacial

Epoch

[I am not more fond of catastrophes than Sir CharlesLyell was. I have done my best to accept a theory for theEnglish gravels which would simply require a gradual