THE UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 3 
A twenty-five acre field called Hensit (or Hensetts) by 
Capon Hall lies just on the watershed between the Aire and 
the Ribble, and supplies water to both rivers. On the Aire side 
of this field are two never-failing springs, and in a small croft 
called '.'The Goppy," close by, is a third.-^ These springs appear 
just on the northern edge of the Silurian, and are doubtless fed 
from the limestone above. They form the stream which runs 
down through the Whyes (or Withes) and the Streets, and 
which, on reaching the North Craven Fault at the Smelt Mill, 
disappears in the limestone. In the meadows about Capon Hall 
are strong springs, carried off by drainage, which are similarly 
brought up by the Silurian rocks from the north side limestone. 
In the Whyes adjoining Black Hill is a stream which in a 
short distance sinks in a pot-hole close to the main fault. 
The streams and springs on Grisedales and Outside sink in 
pot-holes in the limestone along the subsidiary fault which brings 
the Yoredale Shales of Clattering Sykes down against the lime- 
stone of the Ha on the east of Outside. These waters, although 
rising in the watershed of the river Ribble, find their way into 
the Aire by the same route as the Smelt Mill stream. 
Malham Tarn is fed by springs from the limestone on the 
northern edge of the Silurian area. A small stream rises in the 
meadows of High Trenhouse Farm, under Knowe Fell, and flows 
by Tarn Moss into the lake. The principal springs, however, 
are at Water Houses, where there are three or four of some 
importance ; and here, doubtless, most of the water sinking on 
Knowe Fell reappears. On this line " Bursts " have been known 
to occur on Chapel Fell just above Water Houses, when these 
springs were unable to discharge an abnormal supply. There is 
a spring also on the lake side (N.W.) between the old boat 
house and the moss, and several on the east side from under 
Great Close and about Ha Mire which find their way into the 
Tarn. These all appear near the junction of the limestone with 
* Mr. James Howarth, who lived at Capon Hall for many years, tells 
me that in dry seasons he has known this spring ebb and flow. 
