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sea at a higher level than now, were the warm inter-glacial periods, when the country was free of snow and ice, And a mild and equable condition of climate prevailed. This is the conclusion toward which we are being led by the more recent revelations of surface-geology, and also by certain facts connected with the geographical distribution of plants and animals during the Glacial epoch."[1]
H. B. Norton says:
"When we come to study the cause of these phenomena, we find many perplexing and contradictory theories in the field. A favorite one is that of vertical elevation. But it seems impossible to admit that the circle inclosed within the parallel of 40°--some seven thousand miles in diameter--could have been elevated to such a height as to produce this remarkable result. This would be a supposition hard to reconcile with the present proportion of land and water on the surface of the globe and with the phenomena of terrestrial contraction and gravitation."[2]
We have seen that the surface-rocks underneath the Drift are scored and grooved by some external force. Now we find that these markings do not all run in the same direction; on the contrary, they cross each other in an extraordinary manner. The cut on the following page illustrates this.
If the direction of the motion of the ice-sheets, which caused these markings, was,--as the glacialists allege,--always from the elevated region in the north to the lower ground in the south, then the markings must always have been in the same direction: given a fixed cause, we must have always a fixed result. We shall see, as we go on in this argument, that the deposition of the "till" was instantaneous; and, as these markings were made before or at the same time the "till" was laid down, how could the land
[1. "Climate and Time," p. 391.
2. "Popular Science Monthly," October, 1879, p. 833.]
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possibly have bobbed up and down, now here, now there, so that the elevation from which the ice-sheet descended