UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 263 
At the bottom of the shaft is an enormous chamber measur- 
ing 479 feet in length by 82 feet in breadth and 110 feet in 
height. 
The water which enters partly over the lip of the Hole, 
and partly by a subterranean waterfall about 30 feet below 
the surface, sinks through the floor of the chamber, which at 
tlie bottom of the fall consists of boulders of limestone. The 
l)assages which have been explored are all at a considerable 
elevation above the floor of the large chamber, and must thus 
belong to an earlier period in the history of the cave. 
It is impossible to obtain access to the present further 
course of the water owing to the accumulation of boulders at 
the bottom of the cavern. 
It has been surmised that the bottom of the large cavern 
consists of Silurian or Ordovician rocks, but as the solid floor 
is nowhere visible there is no direct evidence, and the fact 
that the water passes a\\ay through the floor of the cliamber 
proves that the bottom of the limestone is not reached, as the 
older rocks are impervious. 
Here then the work of the Committee was commenced on 
Apnl 27th and 28th. 1900. 
On Saturday, April 28th, specimens of water were taken 
from Clapham Beck and from several important springs in 
and around Clapdale, with the object of ascertaining the normal 
composition of the water prior to the introduction of the test 
materials with the following results. 
Results of analysis by Mr. Wm. Ackroyd, of samples of 
water collected on April 28th. 
. ^ . CI, parts 
^ame of Spring. 100,000. 
Moses WeU (S 7) 
Eldon Hall 
Long Kin East (P 8) 
Clapham Beck Head (S 12) . . 
Gaping Ghyll (P 3) . . 
1-37 
1-27 
1-47 
1-35 
1-20 
Average 
1-33 
