| Polypodium calcareum. | Tofieldia palustris. | |
| Equisetum variegatum. | Scirpus pauciflorus. | |
| Poa Parnellii. | Armeria maritima. | |
| Galium sylvestre. | Primula farinosa. |
On the north of Widdy Bank the Main Limestone reaches an elevation of 1800 feet in Bleak Law, which extends from the Weel to the church in Harwood Dale, and above it the gritstone rises to 2028 feet. This first dale, Harwood Dale, is broad and open, the lower part being filled with grassy fields. There is a good road along the east side of it leading to Alston, and at its head Burnhope Seat attains 2368 feet, and Highfield, just above the Grasshill lead-mines, 2322 feet. The dale is 5 miles long from north to south, and joins Langdon Dale, a narrower dale with steep banks and very little population, at Langdon Bridge (1250 feet), and the united streams fall into the Tees a mile above the High Force. The flat stretch of ground round the point where the streams join is called the Whetstone Sill, and here begin Potentilla fruticosa, Salix phylicifolia, Habenaria albida, Crepis succisaefolia, Hieracium gothicum, crocatum, and corymbosum. East of Langdon Bridge the bank of the dale for several miles is steep and girdled conspicuously by the lines of limestone cliff, which, from 2100 feet in Highfield, decline very gradually towards Newbiggin Moor. The peaks of this ridge are Fendrith Hill (2284 feet) and Outberry Plain (2143 feet). From the foot of the Caldron Snout to the head of the High Force the Tees declines in level from 1430 to 1000 feet. The High Force is a very fine waterfall. Here the main stream of the Tees, its waters contracted often into a deep narrow channel, makes a sheer leap of 69 feet into a ravine, the cliffs of which margin the stream for a considerable distance below it. The cliff is dark-coloured basalt, resting upon a mass of dark-coloured indurated shale, and that upon limestone, and when the stream is full the waters flow upon both sides of the massive angular crag which overlooks the main descent. On the Durham side of the river the slope is covered by a large plantation, principally of spruce, and on the Yorkshire side the moor reaches down to the edge of the cliff. A more beautiful spot for a summer-day's excursion than this
