Tithe maps provide a visual means of reference to the apportionments. Each area of land was outlined and given a plot number, unique within that parish, so it could be identified in the apportionment.
In order for the commutation to succeed, detailed large-scale maps were produced for each district showing every field and building which was numbered, measured and crops grown noted. One exception where there was no map was where a parish had tithes eliminated because of land redistribution under the terms of an Enclosure Act; because of this It is thought that around a quarter of English parishes were not surveyed. The numbers of the tithe areas on the map always correspond to those in the schedules to the apportionment.
Tithe maps contain significant detail with dwellings coloured red and other buildings in grey. Other buildings such as mills were often shown. Parish and property boundaries, field names, land use and rights of way are usually defined. There were a series of conventions and signs for land usage but they were not always used.
The most accurate maps can be distinguished from others because they contain both the seal and signatures of the Tithe Commissioners. The aim of the Tithe Commissioners was that the maps be of a uniform high standard, but because it was the landowners who provided the maps, this was not always possible. From 1837 a map was not deemed conclusive evidence of the quantity of the land or be totally accurate unless it was signed off by the commissioners. The system therefore created a two-tier standard.
Tithe maps are considered to be the earliest large-scale map of a locality but there are notable variations in the physical size, scale and accuracy of the maps. Family historians should always include contemporary maps as an everyday element of research so tithe maps should always be checked, not be used in isolation and should be compared with other maps of the area of close dates.
