rNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 287 
P 97, a sink in the corner of the next enclosure to the south 
of the Washfold, on being tested was found to flow underground 
to Far Douk (P 95a), where the water again sank. The same 
was found to be the case with P 98 and P 99. 
The fluorescein from Far Douk was seen two days later 
at God's Bridge S 112. 
Reference to PI. XXX. will show a remarkable parallelism 
in the flow of underground water on Sother Scales Fell. The 
streams between P 82 and P 99 (including these streams) follow- 
ing similar courses immediately they enter the limestone. 
Mere Gill Hole. 
At Mere Gill Hole there is a change in the direction of the 
main joints in the limestone, the strongest set running N. 50° W. 
— this being also a line of faulting, marked on the maps of 
the Geological Survey. 
Mere Gill rises on the upper slopes of Ingleborough and 
flows down the hollow known as Humphry Bottom, and sinks 
in 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 
4th, and the colour was observed on the following morning in 
the spring S 111, on the left bank of Chapel Beck, immediately 
above God's Bridge, and almost in the direct line of the master 
joint at Mere Gill Hole. From Sill the water passed under 
God's Bridge by way of P91, and reappeared below the bridge 
at S 112. 
P 101 and P 102 on Black Shiver Moss receive the waters of 
two small streams, the underground flow being to the lower end 
of Mere Gill Hole, where it joins the waters of Mere Gill, and again 
goes underground, the further course of the water being de- 
scribed above. 
Tatham Wife Hole, at Falls Foot, was visited several times 
during the investigation, but was always dry and consequently 
could not be tested. 
P 102a, on the eastern edge of Lead Mines Moss, not marked 
on the 6 inch Ordnance Map, receives a small stream in wet 
