The Underground Drainage 



were found to be well exposed in a gorge on the course 

 of the stream which feeds the lake. 



On the return journey it was decided to make a 

 detour to examine the water sink to the north of Brown 

 Hill, and this was found to be quite unlike the one 

 below the lake. We struck the stream about half a 

 mile above the sink and followed its course downwards. 

 It flowed on a floor of limestone between sloping banks 

 of peat, and diminished in volume in a manner now 

 familiar to us, as the sink was approached. 



The fall now became steeper, the water rushing over 

 step after step formed by the edges of successive beds of 

 the limestone, but ever diminishing in volume, owing to 

 absorption by the joints in the rocky floor. Eventually 

 we found ourselves in the neck of a great funnel-shaped 

 opening, the sloping sides of which were composed of 

 peat ; in front of us yawned a great well-like opening 

 into which the much diminished stream plunged, throw- 

 ing up clouds of fine, steam-like spray. 



By lying face downwards on the limestone slabs, 

 and leaning out over the abyss, we were able to see 

 a ledge of rock on which the water was falling some 

 70 feet below, only to flow for a few yards and then 

 plunge into a yet deeper chasm which was shrouded in 

 darkness. 



This opening, which we decided to call Funnel Sink, 

 though very uninviting in appearance, seemed to offer a 

 possible means of access to the underground channel, 

 and after some discussion we determined to bring up 

 rope ladders and attempt the descent. 



In the meantime we returned to the main camp in 

 order to see if the fluorescein had put in an appearance 



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