land, loaded with _débris_ from the Arctic shores, which they shed as
they melted in the warmer seas of the south.

This hypothesis explains the carriage of enormous blocks weighing
hundreds of tons from their original site to where they are now
found; but it is open to many unanswerable objections.

In the first place, if the Drift had been deposited under water deep
enough to float icebergs, it would present throughout unquestionable
evidences of stratification, for the reason that the larger masses of
stone would fall more rapidly than the smaller, and would be found at
the bottom of the deposit. If, for instance, you were to go to the
top of a shot-tower, filled with water, and let loose at the same
moment a quantity of cannon-balls, musket-balls, pistol-balls,
duck-shot, reed-bird shot, and fine sand, all mixed together, the
cannon-balls would reach the bottom first, and the other missiles in
the order of their size; and the deposit at the bottom would be found
to be regularly stratified, with the sand and the finest shot on top.
But nothing of this kind is found in the Drift, especially in the
"till"; clay, sand, gravel, stones,

{p. 14}

and bowlders are all found mixed together in the utmost confusion,
"higgledy-piggledy, pell-mell."

Says Geikie:

"Neither can till owe its origin to icebergs. If it had been
distributed over the sea-bottom, it would assuredly have shown some