SHCUKTAIJV S HEPOJrP. 
17th. The water therefore took twelve days to accomphsh 
a journey of IJ miles. 
The extreme slowness of the flow is partly to be accounted 
for by the dry weather which then prevailed ; but when it is 
taken into consideration that the water of Long Churn plunges 
down a very steep fall into Alum Pot, the total depth of which 
is some 300 feet, the gradient of the remainder of the stream 
is considerably reduced. 
The Secretary was informed b}- Mr. Wilcox, of Selside, 
tliat the fluorescein mentioned above had been seen in Footnaw's 
Hole prior to its appearance at Turn Dub. 
The relative positions of Long Churn. Alum Pot. Footnaw s 
Hole, and Turn Dub. will be seen on reference to the plan 
(Plate XV.). 
In dry weather Footnaw's Hole appears as a wide cleft in 
the limestone, with sloping banks of silt and sand round two 
sides, and precipitous limestone rocks on the other two. When 
the streams are in flood after heavy rain, or during the melting 
of snow, the water in Footnaw's Hole rises to the lip and flows 
over down Footnaw^s's Beck into the Ribble. 
Turn Dub is very rarely dry. while it is only in exceptional}}' 
wet weather that water flows from Footnaw's Hole. 
Thus it would aj)pear that Footnaw's Hole is a flood outlet, 
and only comes into operation when the underground passage 
leading to Turn Dub is full and. therefore, unable to take the 
excess of water. As the lip of Footnaw's Hole is just below 
the 1,225-foot contour, and Turn Dub just below that of 1,200 
feet, there cannot be a fall of more than 25 feet from the former 
to the latter. 
Further, since in ordinary weather, when the stream is 
issuing from Turn Dub only, the water in Foonaw's Hole stands 
some 20 feet below the ground level, it will be seen that there 
must be a siphon-like passage below the river ; and since the 
passage must be constantly filled with water up to the level of 
the overflow of Turn Dub. it will account for the ver}' slow passage 
of the fluorescein over at least this part of the journey. 
