The ballyboe, a townland unit used in Ulster, was described in 1608 as containing 60 acres of arable land, meadow, and pasture. However, this was misleading, as the size of townlands under the Gaelic system varied depending upon their quality, situation and economic potential. This economic potential varied from the extent of land required to graze cattle to the land required to support several families. The highest density of townland units recorded in Ulster in 1609 corresponds to the areas with the highest land valuations in the 1860s.
