Geological Survey of Great Britain. Great Britain. Geological Survey of England and Wales. Sheet 270 drift. Great Britain. Ordnance Survey of England. North Decimal Degree 51.500000. South Decimal Degree 51.3333. East Decimal Degree 0.0000. West Decimal Degree -0.4167. In upper left margin: Ordnance Survey of England. Relief shown by contour interval and spot heights. Transverse Mercator projection. National grid system. "Original Geological Survey on the one-inch scale published on Sheets 1, 6, 7 and 8, Old Series, 1861-1868. Drift added 1869-1889. Re-surveyed on the six-inch scale: the north-west corner by A. C. G. Cameron et al., 1898-1902; the remainder by Henry Dewey and C. E. N. Bromehead, 1911 to 1914. Minor amendments by S. Buchan, 1935 and 1941.".