UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 261 
Lower down it receives several otlier streams on its right 
bank and finally flows on to the Mountain Limestone at an 
elevation of 1,350 feet. Almost immediately on entering the 
limestone area the stream commences to sink. It goes to no 
great depth however, as it reappears several times within a 
distance of 50 yards. It then flows over the lip of a roughly 
circular, well-hke abyss — the well-known Gaping Ghyll Hole. 
In wet weather, the bed of the Fell Beck, between tlie 
point where it flows on to the Mountain Limestone and Gaping 
Ghyll, is entirely occupied by the stream, but in drought and 
moderate weather there are several dry stretclies as described 
above. In either case the destination of the water is the same, 
it plunges down into the great crater-like pit of Gaping Ghyll 
(Pis. XXXI. and XXXII.) to a depth of 365 feet from the surface. 
The descent of Gaping Ghyll was first made b}^ Mr. John 
Birkbeck, of Settle, in 1872 ; he, however, was unable to pene- 
trate further than the ledge (see Plate XXIV.) in the main 
hole 190 feet from the surface. 
The first complete descent was made in August, 1895. by 
Mons. E. A. Martel, of Paris, who succeeded in reaching the 
bottom by means of rope ladders. 
The " pot " was descended by members of the Yorkshire 
Ramblers' Club in May, 1896, when extensive surveying opera- 
tions were undertaken in the large chamber at the bottom of 
the shaft, and in the passages leading tlierefrom, the results of 
which we are enabled to present in Fig. 4 and PL XXIV. 
by the courtesy of the Committee of the Yorkshire Ramblers' 
Club. 
As it was found impossible to complete the survey on this 
occasion a descent was made at Whitsuntide. 1903, on which 
occasion three members of the L^nderground Waters' Committee* 
were enabled, by the kindness of the club, to make the descent. 
Full accounts of the various descents and of the chambers 
and caverns explored will be found in the Yorkshire Ramblers' 
Club Journal, t 
*Mr. S. W. Cuttriss, Mr. A. R. Dvverryhouse, and Prof. Kendall, 
t Vol. I., pp. 65-74, 123-133; Vol. IT., pp. 48-51. 
