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and crushed slate-heds carried far down the slope.
The Avhole effect was so graphically one of vigorous
and irrésistible movement, that I examined carefully
some cottages and old trees in hope of fiuding some
evidence of twisting or other irregular dislocations,
but there appeared to he none such ; the movement, if
it Avere sufficiently rapid to make a sign during the
life of a cottage or a tree, evidently pervaded the
Avhole mass uniformly.
It seems to me almost self-evident that Avherever
there is a slope, he it ever so gentle, the soil-cap
must he in motion, he the motion ever so slow ; and
that it is dragging over the surface of the rock
heneath the blocks and boulders aaTiIcIi may he
emhedded in it ; and frequently piling these iu
moraine-like masses, Avhere the progress of the
earth-glacier is particularly arrested as at the
contracted mouth of a valley, Avhere the Avater
percolating through among them iu time removes
the intervening soil. As the avalanche is the
catastrophe of ice-movemeiit, so the laird-slip is the
catastrophe of the movement of the soil-cap.
As I have already said, I should he the last to
undervalue the action of ice, or to doubt the abundant
evidences of glacial action ; hut of this I feel
convinced, that too little attention has been hitherto
given to this parallel series of phenomena, Avhich
in many cases it Avill he found very difficult to
discriminate ; and that these phenomena must he
carefully distinguished and discriminated hefore we
can fully accept the grooving of rocks and the
accumulation of moraines as complete evidence of a
former existence of sjlacial conditions.