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Thirdly. The action of the sea (when Rombold's Moor was 
partly submerged) first undermining the cliffs, then carrying 
the blocks down hill, and lastly placing them or piling them 
up in their present positions. 
Fourthly. The action of coast-ice during the glacial period, 
which must have been adequate to detach, launch, and 
disperse blocks on a large scale, on a sea-coast such as the 
north-east escarpment of Rombold's Moor must have 
formed. 
I can believe that the first two agencies have been at 
work through every geological period up to our own times 
on the north-east side of the moor, for we well know that 
the tumbling down of blocks through gravitation and rain 
is a process now in action over vast portions of the earth's 
surface. But infinitely more have the two latter causes 
performed the colossal work now shown on the north side 
of the central part of Rombold's Moor. That the sea has 
rushed over the whole of Rombold's Moor is evident from 
a variety of phenomena, some of which have been already 
described, while others will be noticed shortly. That 
floating ice must have acted on the north-east side of 
Rombold's Moor would appear from the beautiful display 
of glaciated and grooved rock-surface a short distance from 
the Cow and Calf, about 900 feet above the sea-level, men- 
tioned by Mr. Mackintosh in his paper read at Sheffield, 
and which I myself have examined repeatedly. The strm 
indicating a movement from the West. I feel convinced that 
no glacier could have polished and ground this rock-surface 
as it now appears, and this I infer from the physical 
geography of the district to the west and north. That 
the scattering of the surface blocks under consideration 
could not have been the effect of a glacier flowing down 
the valley of the Wharfe, would appear from the almost 
total absence of Limestone blocks and fragments on the 
