Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne (1867).djvu/100

82 The lower part of the vale of the Aln is not more than from 2 to 4 miles wide. The most interesting botanical station near Alnwick is Ratcheugh Crag, another portion of the basaltic dike which from this point runs across the county in a south-western direction. Here occur ,  and ,, , , and several other interesting species. The area of this district is about 150 square miles. None of the hills, except those west of Alnham, rise distinctly into the Middle zone.

The course of the Coquet is nearly in a line from west to east, and its length about 40 miles. For several miles its watershed ridge on the north forms the boundary between England and Scotland. The upper part of the dale has entirely the characteristic Cheviot aspect—a narrow grassy hollow, with a stony unenclosed moorland road, at the bottom a brawling mountain streamlet, excellent for trout-fishing, grassy hills rising steeply from this on either bank, very little actual crag, and what there is usually down by the stream-side, but often great sweeps of porphyritic debris stretching down the banks, flecked with green of brake and purple of foxglove. At the corner, between the Usway Burn and the Breamish, Windygyle is quite 2000 feet in altitude, and between the Alwine and Hedgehope, Cushat Law and Weather Cairn reach 2019 and 1836 feet. From this point the ridge westward along the Scotch border, though further up the river is not so high. Between the two forks of the Coquet, where Watling Street crosses the border, Chew Green Camps are