OF THE DISTRICT, 
153 
higher and still higher strata, till it crosses the magnesian limestone. In 
the language of Mr. Smith, the streams in the Yorkshire dales first overcut 
and afterwards undercut the strata. Hence it happens that on the Tees, 
Swale, Yore, and Wharfe, especially, the lowest beds of the limestone 
series are exposed about the middle of the length of the dale, and in 
each valley waterfalls occur in the upper part, and rapids in the lower 
part, on the same limestone beds. 
The lowest places on the summit ridge or Penine chain correspond 
generally to the terminations of the longest dales — as the head of Maize 
beck and the Tees in Teesdale, Stainmoor along the course of the Greta, 
He! gill at the head of Yoredale, and a pass at the head of Swaledale above 
Kirby Stephen. 
Teesdale . — The Tees rises on the east front of Cross fell, which 
is 290! feet high, (O S.) flows eastward four miles through the Yoredale 
limestones to the Tyne bottom limestone, and receives on its right 
bank a stream called Trout beck, which flows north-eastward from a 
hollow in the Penine chain on the main limestone 2400 feet above the 
sea. The united stream flows south-east, first in Tyne bottom lime- 
stone, and afterwards in Whin sill, to the Weel, 1489 feet above the sea, 
then falls over the basaltic rocks of Caldron snout, about 200 feet, and 
receives Maize beck. The general course of Maize beck is E. N. E. One 
of its branches originates in a hollow of the Penine chain west of Scor- 
dale head, (called Higli-cup-nick), on Tyne bottom limestone 1850 feet 
above the sea. Another branch begins opposite Hilton beck, united to 
the preceding it flows in basalt to Caldron snout. From Caldron snout 
the Tees still runs E. N. E. till it receives the long stream of Harewood 
beck flowing south-east, which direction it takes and continues in basalt 
to below the Miner’s bridge, thence south-eastward in Yoredale lime- 
stone, grits, and plates, to near Egglestone, having received on the 
right the Lune flowing E. by N., thence south-east to Egglestone 
abbey in plates and grits above main limestone, receiving on the 
right the waters of Balderdale and Deepdale, E. by N, Two miles 
below it receives the Greta, 
x 
