Questions related to maps and land records.
How big is County Longford?
County Longford is a small jurisdiction by many standards, at 421 square miles, or 1091 sq. km. By comparison, Metropolitan London is 610 square miles. New York is slightly smaller than Co. Longford, at 368 sq. mi. Greater Toronto, Canada is 243 sq. mi. In Australia, the National Capital Territory has an area of 910 sq. mi, more than double the size of Co. Longford. In Ireland, Co. Longford is the 4th smallest county.
I think I know what an acre is. What about rood and perch?
Actually, the Irish acre was bigger than the English acre historically. It took 1.62 English acres to make 1 Irish acre. Or alternatively, 1 English acre is .617 Irish acres. This needs to be taken into account in looking at older leases, and at records like the tithe applotments. A rood is 1/4 acre, while a perch is 1/40th of a rood. On maps or in land documents the amount of land was designated in A-R-P, or acres, roods and perches.
Why are maps important?
Maps are absolutely vital in sorting out the geographical relationships between members of a family, or even the origin. There was a clue to the origin of a WALSH family - they were from "Canaan Airdes" in Co. Longford. Someone had written this down as they thought they heard it. There was no such place, but a look at the Ordnance Survey maps showed there was the town of Kenagh, and just a few kilometres northwest was the townland of Ards. Problem was solved, and records were found in the church registers for Parish Kilcommock.
What kinds of maps are useful?
While virtually any good map with sufficient detail can be useful, start off by locating maps of Co. Longford that show the parishes, the baronies, and the poor law union boundaries. Then see if you can find for the parishes of interest a map showing the townland boundaries.