Geological Survey of Great Britain (England and Wales) Great Britain. Ordnance Survey. Sheet 338 drift. North Decimal Degree 50.6500. South Decimal Degree 50.4833. East Decimal Degree -3.7167. West Decimal Degree -4.1333. 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 la Beche, F.R.S. Published on Sheet 25, Old Series. Resurveyed on the six-inch scale by W. A. E. Ussher et al.".