GILLIGAN : EFFECTS OF STORM OX BARDEN FELL. 385 
up to a depth of six feet, and tlie walls on either side thrown 
down, leaving gaps about twenty feet Avide. The heiglit at which 
the water liad stood at the fell side of the top wall was easily 
traceable by reason of the bracken and grass infilling the chinks. 
This height varied from eighteen inches to three feet six inches, 
?«ccording to the lie of the ground. The water crossed the road 
at a point where the ground rises to a crest in the line of the 
new channel. In this new channel was found remarkable 
evidence of the cutting power of a mountain torrent. Careful 
measurements showed that in many places the solid grit had 
been removed to a depth of twenty feet, while the greatest 
width was t\A'elve feet. The deepest holes were always found 
succeeding a place where the water had been imprisoned in 
a narrow channel, and the material scooped out of the hole has 
been piled up on the lower side to form a boulder bar. 
Scape-colks " similar in their mode of origin, i.e., con- 
striction of the water channel, have been described by Suess* 
as occurring in the bed of the Danube during the construction 
of dams for the purpose of diverting the river. Much of the 
rock in this part of the channel is crashed, as by faulting, and 
a vein was found at one part, but a search failed to reveal 
any metalliferous ore, though on the other side of the valley of 
the Wharfe the veins in the limestone bear galena, which has 
long been worked. It seemed at first as if the course of the 
stream had been determined by a pre-existing channel along 
a line of fault, but I was assured by those in the neighbourhood 
who knew the ground thoroughly that no channel had existed 
there prior to this storm. 
Another interesting feature, which was noticed both in 
this channel and at most other places round the fell, was that 
a stiff boulder clay, containing limestone pebbles, which covered 
the ground, had offered a powerful resistance to the cutting 
action of the current, and had preserved the underlying rock. 
The wall sejjarating this field from the rock-strewn fell above 
had, in common with others, been breached, and a^fforded evidence 
of previous storms, not so violent perhaps as the present one, 
but nevertheless bringing down much material from the higher 
Suess, '"The Face ot the Earth,"' \'ol. II., p. 343. 
