ce as
Arthur's Seat, had been a witness of the catastrophe; and that, instead
of having merely to reason respecting it after the lapse of more than
four thousand years, he had been enabled to bear testimony regarding it
from the evidence of his senses. In the first place, let me remark that
the sinking or downward motion of the earth's crust would be altogether
inappreciable by sense; in the next, that the depression, even when it
had reached its acme, would in no sensible degree affect the contour of
surrounding objects. Even at the end of the forty days, when the five
thousand feet of depression had been reached, the gradient of
declination across the sunken area would not exceed _ten_ feet per mile,
and across the larger diameter would amount to but _six feet eight
inches_ per mile. Of course, at the end of the twentieth day the
gradients would be represented by but one half these sums, and would be
altogether inappreciable in the landscape; the hills would seem quite as
high as before, and the valleys not more profound. The only sensible
sign felt or visible of what was taking place would be simply a
persistent rising of the sea at somewhat less than twice its rate of
flow during stream tides. Ocean, as if forgetful of its ancient bounds,
would continue to encroach upon the land. On the second day the greater
part of what is now the site of Edinburgh would be covered; on the
seventh day the tide would have reached the vessel perched on the top of
the hill now known as Arthur's Seat; on the sixteenth day the highest
peak of the Pentlands would have disappeared; and in nine days more the
distant summit of Ben Lomond. From the roof of the slowly drifting ark
nothing would then have appeared save a shoreless ocean. But it would
have taken yet other eleven days ere the proud crest of Ben Nevis, the
highest land in the British islands, would have been submerged; and the
eve of the fortieth day would have seen it covered by little more than
five hundred feet of water. An actual witness, in such circumstances,
however intelligent, could have but testified to the persistent rise of
the sea, accompanied mayhap by rain and tempest; he could but tell how
that for many days together it had been flood without ebb, as if the
fountains of the great deep had been broken up; and that at length he
was encompassed by what seemed a shoreless ocean. But he would certainly
depart perilously from his position as a witness-bearer, were he to