CUTTRISS : NOTES ON THE CAVES OF YORKSHIRE. 317 
Travelling eastwards the limestones increase very much in 
thickness and hardness, containing many caverns of considerable 
dimensions and extent. Above Lofthouse in Nidderdale a tri- 
angular fault has brought the Yoredale beds to the surface. Down 
to this point the river Nidd, like other well-conducted rivers, runs 
its course above ground, then sinks out of sight and continues its 
underground course for over two miles, appearing to light again 
close to the roadside below Lofthouse. Not far from where the 
water sinks the underground passage can be entered at an opening 
called Manchester Hole, but, being obscured by thick vegetation, it 
is easily unobserved. Climbing down alx)ut 20 ft. the level of the 
water is reached, and a commodious passage entered. About 300 ft. 
from the entrance this opens out into a chamber 100 ft. long by 
40 ft. high. At some period of its history it has been completely 
filled with earth, but the water has since waslied part of it away at 
one side, leaving a steep bank of tenacious mud, which has to be 
crossed by cutting steps in it. At the further end of the chamber 
the water continues along another passage, and by dint of wading, 
scrambling over fallen rocks, and crawling at full length in the 
water, the river can be followed for several hundred feet. The roof 
eventually comes down close to the surface of the water, which at 
that point is held back by a constriction in the passage, and further 
progress is impossible. The rock contains fossils of the Productus 
giganteus. 
About 350 yards below Manchester Hole, following the dry 
course of the river on the surface of the ground, is another opening 
in the face of a low cliff, known by the name of Goyden Pot, giving 
access to a large chamber and several passages, along which the 
river winds its way. The passage to the left, which appears the 
natural course to take, leads to an opening in the perpendicular wall 
of the cavern, 20 ft. below which the water can be heard rushing 
along to still lower regions. By keeping to the right of the 
entrance passage the cavern can be entered without difficulty, and 
some scrambling of a varied character indulged in. At the far end 
of the cavern a descent of about 1 8 ft. can be made to the lower 
level of the watercourse, and if a thorough wetting is not objected 
