Although the Agricultural Census and similar surveys, like the 1801 Crop Returns, reported on broadly the same units as the Census of Population, they often either provide or need different overall areas for the units, which are recorded here. Areas from the Agricultural Census may be different because that survey usually included the whole of a farm within the parish in which the farmhouse was located even if parts of the farm were in other parishes. The 1801 Crop Returns did not list total parish acreages and ...

neither did the 1801 Census of Population, so we use the 1831 acreage if available, or failing that the 1851 acreage; in both cases these should be the overall acreages of mother parishes, including component townships, etc. For counties in 1801, we include only the acreages of parishes which are included in the returns and for which we have been able to find an acreage. NB some of these areas come from the farm surveys themselves, but others are derived values computed from other sources; in either case, they are the most appropriate areas to use as divisors when working with farm survey data, if rates are to be computed relative to the total area of the unit rather than the farmed area. Where totals are available including and excluding areas of water, the figure for the unit area excluding water is held here.