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tions. The cliffs and platforms of tlie Yorkshire moors 
could not have been formed by rain, because on hard 
rocks and on grass-covered shale rain cannot act in a 
state of dispersion so as to leave longitudinally-continuous 
indentations. When rain-water acquires denuding power 
by becoming concentrated into streams capable of washing 
down hill sides, it always tends to produce, not horizontal 
indentations or continuous terraces, but gulleys at consider- 
able intervals doion, and not along, the faces of the declivities. 
Where terraces already exist, rain-torrents tend to break up 
their longitudinal continuity. 
At the base of, and insinuated into, the crevices and 
cavities of the cliffs, at Plump ton and elsewhere, we often 
find foreign pebbles, with or without clay, which show that 
something more than atmospheric agency has there been at 
work; and a detailed examination of all the phenomena 
connected with these rocks, with the Brimham rocks, the 
Wharnoliffe rocks, and many other inland cliffs, would, I am 
convinced, lead to the conclusion that the sea has washed 
away the softer beds at a lower level; abstracted large blocks 
and removed them to positions where they could not have 
fallen; excavated narrow inlets up inclined planes; rounded 
many of the loose blocks, piled them on one another; and 
performed other feats entirely beyond the power, and 
incompatible with the mode of operation, of atmospheric 
agents. 
Wind charged with sand, and its action concentrated by 
pre-existing indentations, has modified the shapes of many of 
the rocky pillars on Brimham Moor and elsewhere, but it 
could not have formed the cliffs, abstracted blocks so as to 
leave passages between pillars,* left uniformly ground-down 
* The sides of these passages often consist of unweathered divisional planes, 
and where these planes have been acted on by rain, vertical small furrows have 
resulted. 
