288 UNDERGRO^JND WATERS OF KORTH-WEST YORKSHIRE. 
weather only. Tliis. on being tested with fluorescein, was found 
to communicate witli S 116, near the "Engine Sheds" at the 
Ingleton Granite Quarries. 
From P 102a to the Crina Bottom Valley there are no sinks 
of importance, and the next stream to be studied was Hard Gill. 
This stream rises, on the south side of Ingleborough, in 
a spring at 1,600 feet above the sea, and flows for a distance of 
about half a mile over boulder-clay. It then reaches the bare 
limestone and commences to sink near the eastern corner of the 
croft (P 103) at Crina Bottom [PL XLI.. Fig. 1]. 
In wet weather the stream is not entirely absorbed at this 
point, but flows on past the house at Crina Bottom, and enters 
the rock at Rowan Tree Hole (Rantree Hole on 6 inch map), 
P 104. 
At the time of the experiments the Avater of Hard Gill was 
entirely absorbed between the point where the 1,200-foot contour 
crosses the stream and the eastern corner of the croft, and con- 
sequently the investigation of Rowan Tree Hole, the primary 
object of the excursion, had to be abandoned. 
It was found, however, that the bulk of the water was 
absorbed at the point where the 1.200-foot line crosses the stream, 
and consequently it was determined to introduce one pound 
of fluorescein into the open joint down which the water was 
flowing. This was done at 2 p.m. on November 11th, and before 
7 a.m. on the 12th, the water of the large spring at the reservoir 
(S 119) in the Greeta Valley was strongly coloured, and by 8 a.m. 
the water in the Ingleton water pipes was also affected. 
After introducing the fluorescein a general survey was made 
ot the direction of the joints in the limestone in the neighbour- 
hood of the sink and on the clints above Crina Bottom, with 
the following results : — 
Joint at " sink " X. 55° W. 
On " clints " near sink . . . . . . N. 55° W. 
On " clints " above and to the ] (main) N. 50° W. 
west of Crina Bottom J (secondary) S. 25° W. 
The spring at the reservoir is thrown out close to the line 
•of junction of the Mountain Limestone with the underlying 
