The Cheviot Hills form a long ridge culminating to the N.E. in the Cheviot, 2676 ft. high. From the Cheviot hill-mass College Burn flows N. by E., Harthope Burn to the N.E., and the River Breamish to the E., and all join the R. Till which flows north-westwards to join the Tweed. Between College Burn and the Breamish the Lower Old Red Porphyrites form a steep curved slope fronting to the N., N.E., and E., and trenched by the valleys of several small burns. From the foot of this slope Carboniferous rocks extend towards the coast with a gentle dip outwards from the porphyrite area. Between College Burn and Wooler the junction between the Carboniferous rocks and the porphyrites is apparently a faulted one, but south of Wooler the latter rocks are unconformably overlaid by the Carboniferous. Glaciation. The direction of striae on the rock surfaces and the transport of boulders show a movement of the ice along both sides of the axis of the range from S.W. to N.E. at some stage of the glaciation. Thus, on the Tweed side, the striae and the transport show a uniform movement to the N.E., and on the Northumbrian side boulders have in general gone to the N.E. Across the northern end of the range and for at least ten miles down the eastern side, however, a distribution of rocks from the Tweed, together with a shifting round of the direction of striae and of the long axes of drift mounds, indicates