IV.—On some Points connected with the Drift of Derbyshire and Yorkshire

Extract

In a paper of mine on. “The Glacial Phenomena of the Yorkshire Uplands,” read before the Geological Society of London in the spring of 1872, compared the valley of the Wye in Derbyshire to those of the Aire and Calder in Yorkshire. This was a mistake: the Wye rises on the west side of the geological axis and crosses the anticlinal; but its valley does not cross the physical axis, which is nowhere broken through, as in the cases of the Aire and Calder. The lowest part of the watershed at the head of the Wye basin is at Doveholes, near Chapel-en-le-Frith. I made some observations by aneroid to ascertain the height of this point. The watershed south of Doveholes was by aneroid 1300 feet above the sea, and that north of Doveholes 1250 feet; but as the glass was falling on the day of my visit, these heights are too great by somewhat less than 75 feet, the total amount of the fall. This will make them between 1225 and 1300, and between 1175 and 1250 feet respectively. On another occasion I estimated the height of the watershed north of Doveholes at 1200 feet, and that on the Peak Forest Railway at 1175 feet. A couple of miles to the N.N.E. I found Sparrow Pit to be 1350 feet above the sea, and Perrydale 1200; the plateau above Perrydale 1350; the watershed under Mam Tor 1500; and the lowest point of Rushup Edge 1525 feet above the sea.