272 Address to the Lincolnshive Naturalists’ Union. 
A good illustration of this may be seen in the district I am 
speaking of, for Hardwick Hill, which stands out as a land mark, 
at the far end of Scotton Common, is mainly composed of gravel 
and sand, while the unyielding clays of the Lias are worn away 
to their present depth below the Lincoln Cliff. 
For actions, such as I have described, unlimited time is, I 
need not say, required; but, that given, from the planed down 
surface of land emerging from the sea, we get the earth in its 
present form, with its infinite variety of mountain and valley, hill 
and dale. ° 
Of course there are volcanic, and other forces, that aid in the 
construction of the earth’s surface, but they lack the universality 
and ceaseless operation of rain, and there is no time to speak of 
them now. 
It is to the eroding action of rain, that we owe, in the main, 
the present features of the “the great dragon land.” 
ONE more phase, in the life history of the area we are 
considering, I have still to record. 
After the chalk sea had disappeared, and the Tertiary age,— 
which may be called the latter days of geology,—had set in, the 
land underwent, for a great length of time, varying periods of 
elevation, subsidence, and rest; during .which the North Sea 
appeared, and the principal physical features of our islands were 
developed; but, in the later Pleistocene epoch,—a period 
approaching our own days ina geological sense,—a great change 
took place. The Glacial conditions, which now prevail in the 
arctic regions, gradually invaded our land. ‘The whole country 
sank to a considerable depth below its present level, and a great 
portion of Lincolnshire was covered with floating ice, which 
scored the rocks, and poured on its surface volumes of mud and 
clay, mixed with stones and boulders, which now pave the 
streets and market places of Gainsborough and Lincoln. And 
when, at last, all this had passed away, and the land had risen 
