282 UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 
stream was still coloured on April 5th, at 1.30 p.m., when the 
remainder of the charge was sent down in a flush. The stream 
was slowly dwindling on the 5th, it having been in flood on the 
previous day. 
All the springs in the neighbourhood were carefully watched 
for several days, but no result was observed. 
Consequently this experiment was repeated and it was 
eventually found that the fluorescein reappeared at Footnaw's 
Hole, having, like the water from P 41, joined the deep-seated 
flow from Alum Pot to Turn Dub. 
P 51 was quite dry owing to the diversion of Old Fold Spring 
previously mentioned. 
This was the last stream in passing northwards found to 
communicate with Turn Dub. 
The above streams from P 19 on the south to P 34 on the 
north, occupy a wide valley and would, with the exception of 
Gill Garth Beck (S 42 to P 37), ah drain into Selside Beck were 
they not swallowed into cracks in the limestone. 
There would appear to be two distinct sets of channels 
below Font Green — a deeper and a more superficial one. 
The water flowing by the deeper channels, viz., that from 
Alum Pot, Long Churn. P 41 and P 52, reaches tlie Ribble by 
way of Footnaw's Hole and Turn Dub, while the shallower set 
issues at the lower end of Font Green and joins Selside Beck. 
The deeper set has been shown to be of pre-glacial origin 
(p. 281), and it seems highly probable that the shallower set is 
of recent date. The channels are not so well marked as in the 
case of the deeper set. The streams which flow in the 
shallower set of channels might in some instances flow into 
Alum Pot if they continued on the surface, but when captured 
by the joints they are carried down the hillside to emerge on 
the slope below the mouth of that opening, and consequently 
could not enter the lower set of passages unless another deep 
chasm existed, connecting these with the surface. 
P 50 is a small pot-hole on Bent Hill Rig. It is usually dry 
and consequently has not been tested. 
There are several small springs in the pastures between 
Bent Hill Rig and the River Ribble (viz., S 75, S 76, S 77, 
