Geological Survey of Great Britain (England and Wales) Great Britain. Ordnance Survey. Sheet 325 drift. North Decimal Degree 50.8333. South Decimal Degree 50.6667. East Decimal Degree -3.3167. West Decimal Degree -3.7167. Relief shown by contour interval and spot heights.Transverse Mercator projection. National grid system. "Original Geological Survey on the one-inch scale by Sir H. T. De al Beche F.R.S. Published on Sheets 21, 22, 25 & 26 Old Series before 1845. Resurveyed on the one-inch scale by W.A.E. Ussher before 1888. Transferred to New Series map & published Dec 1899.".