Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne (1867).djvu/120

102 Limestone attains the height of 488 feet at its highest point west of Newbottle.

This drainage tract includes the heart of the county from east to west, and comprises fully one half its total area.

The Tees rises in Cumberland, on the east side of Cross Fell (2901 feet). It first touches Durham at Crook Burn, 5 miles above the Caldron Snout, and for the whole of the remainder of its course forms the southern boundary of the county. This point is 1600 feet above sea-level, surrounded on all sides by desolate dreary moors. There is scarcely a lonelier tract anywhere in England than the expanse of wild moor that fills up the whole area between Alston, Langdon Bridge, and Dufton, 15 miles across in each direction, with hardly a house or a trace of cultivation to be seen. For 5 miles the river falls but little, but spreads out in a large tarn-like expansion called the Weel, quiet enough for Ranunculus peltatus and Potamogeton rufescens to grow in it. At the Caldron Snout the scene changes. First, the water becomes ruffled by shelves of rock, and then with a rush, the noise of which mingles with the whirr of grouse, and the bleating of mountain sheep far away amongst these lonely hills, the stream breaks a gorge through the great sweep of basalt, forming in doing so a series of broken rapids, leap after leap in tumultuous succession, the brown stream dashed by the first into an angry white foaming torrent rushing from ledge to ledge down a winding rocky channel, till at last it frees itself from the gorge and spreads out, like a ray of light as it issues from a prism, over a back-ground of broken sharp-edged basaltic columns. The