THE UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 4i 
formed by the meeting of two planes of saturation, one towards 
the dip slope and the other towards the rise of the beds, will be 
nearer to the foot of the escarpment or basset-edge than to the 
edge which is covered by newer rocks (Fig. 5). 
3. The influence of alternating wet and dry periods upon 
the limits of saturation will be that during rainy periods the 
pnng 
Fig. 5. 
saturation levels will rise and, the points of escape being 
approximately constant (though new ones may come into opera- 
tion at such times), the gradients will steepen. In the simple 
case of horizontal beds forming a plateau with free edges all 
round, the saturated rock will assume the form of a dome. In 
the intervals between periods of rainfall the gradients will con- 
tinuously diminish, and in the case of the plateau postulated 
above, the dome representing the saturated rock will flatten 
(Fig. 6). All the gradients will tend to zero. 
Fic. 6. 
Applying these principles to the problem under consideration, 
we will assume that the waters of Smelt Mill Sike are trans- 
mitted through a series of master-joints directly to Malham Cove, 
and that the water entering at Malham AVater Sinks flows 
beneath the limestone plateau in a similar parallel series of joint- 
fissures. 
