MOVEMENTS OF UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 195 



Mere Gill Hole. 



Mere Gill rises on the upper slopes of Ingleboro', and flows down 

 the hollow known as Humphry Bottom, and sinks m a large open joint 

 running N. 50 W. at Mere Gill Hole, on Mere Gill Piatt. 



Mere Gill was charged with fluorescein at 1 p.m. on July 4 and the 

 colour was observed on the following morning in the spring S 111, on the 

 left bank of Chapel Beck, immediately above Gods Bridge, and almost in 

 the direct line of the master joint at Mere Gill Hole. From bill the 

 water passed under Gods Bridge by way of P 91, and reappeared below 

 the bridge at S 112. ^ , „, . -mt 4. 



The small streams sinking at P 101 and 102, on Black Shiver Moss, to 

 the south-west of Mere Gill Hole, have not as yet been tested. 



Passing along the hillside in a south-westerly direction, the next 

 stream of importance is that at Crina Bottom, the course of which has 

 been described in a previous report. 



Long Kin West. 



The group of potholes known as Long Kin West, P 108, was 

 examined, and it was found that no water was flowing into them nor was 

 there any evidence that a stream had lately occupied any of them, and, 

 consequently, no test was possible. 



By visiting these pots during heavy rain, when there is a large amount 

 of local surface drainage, we may be able to connect them with some ot 

 the neighbouring springs. 



Grey Wife Sike. 



On referring to the first report of the Committee, it will be found that 

 an unsuccessful attempt was made to trace the water flowing down P 1, 

 at the foot of Grey Wife Sike. 



On that occasion methylene blue was employed, and, as that reagent 

 has since been found to be practically useless for our purposes, we deter- 

 mined to try again with fluorescein. j x -d i 



Accordingly, about half a pound of fluorescein was introduced at ±^1 on 

 July 2, and another similar quantity on July 4. This came out at Moses 

 Well, S 7, a large spring on the right bank of Clapham Beck, on the 5th 

 and 6th. 



The River Greeta. 



The last piece of work undertaken this year was the tracing of the 

 underground course of the main stream in Chapel-le-Dale. 



This stream flows underground in many places in normal weather, 

 but when in flood occupies a well-worn channel on the surface. 



The upper part of the stream, above Weathercote, is known as Winter- 

 scale Beck, the portion between Weathercote and Gods Bridge as Chapel 

 Beck, and from that point down to Ingleton as the river Greeta. 



The stream rises on the moors near the tunnel of the Midland Rail- 

 way, above the Ribblehead Viaduct, and soon sinks in a series of pot- 

 holes, there being, however, a well-marked open flood channel. 



The whole stream again comes to the surface at the mouth ot Gate 

 Kirk Cave, S 107, and another large spring a few yards away. 



It then flows through several large pools, and again goes underground 

 at P 85, leaving the stream bed dry, to again emerge about seventy yards 



