I have recently been researching my paternal family tree, luckily we are the first generation to live outside Scotland so the Scottish Ancestry website has been invaluable. Most of the post 1800 records are digitised and indexed and allow partial and soundex searching. This has been useful as my family name changed from Jaffray to Jaffrey.
With a little information from my father I'm now back to the late 1700's. I am building a skinny tree, digging down the paternal line each time.
My family were all farmers, until my Great Grandfather who was a police sergeant in Aberdeen. The interesting thing was that his father and his grandfather both worked the land in the Lonham area of Aberdeenshire and lived in to their 90's. George my great grandfather was the first family member to seek work in the city and died of hypertension in his 60s. There's a pretty simple lesson there I think.
Anyway back to the title, as a sideline to this research I often come across the term townland. This will be familiar to anyone living in Northern Ireland. It's a small geographical unit of land used in Ireland and Scotland , and believed to be of Gaelic or Goidelic origin.
Townlands are always different sizes, and the reason they are is because they were originally based on the area that could support a fixed number of cattle, thus they vary in size depending on the land quality.
From the wikipedia entry for townland; A complicating factor was that in Gaelic times, land was measured in terms of its economic potential rather than in fixed units of measurement: by the number of cattle that an area of pasture land could support, or by the time taken to plough an area of arable land. Therefore the size of an "acre" in this system could vary enormously depending on the quality of the land.