An acre comes from the Latin word ager meaning field which led to the Old English aecer. Originally an acre was the strip of land that could be plowed in one day by a team of oxen pulling a plough. Ideally there would be a team of 8 oxen in a team, but it could be four or fewer depending on your wealth and whether your neighbour would lend you his. Clearly the more oxen you owned the more land that you could work and the more likely you were to be able to have surplus supplies. So far so good. Beyond that point it becomes a bit more complicated. Weights and measures were not standard – think of it more as a rule of thumb.
You could then divide every acre into 4 roods (1 rood = ¼ of an acre) and each rood contains 40 perches or 40 rods. The perch comes from the Latin name for a measuring pole whereas a rod comes from the Old English rod or goad that the ploughman used to encourage the oxen on – or put another way, if I’ve got it right – a rod, a pole and a perch are exactly the same thing and are the name given to the device by which the land was measured and which again was initially dependent on where you were as to what size it actually was! These days a rod is 5.5 yards and this seems to have been typical of a medieval ox goad.
Acres could also be divided into long-furrows or furlongs – each furrow ran the length of the acre strip of land. This was the distance that the ploughman ploughed before turning the plough = ideally it should be 40 rods or 220 yards if you prefer yards to rods, poles or perches.
Acres were standardised in 1878 to 4840 square yards and because of the practical fact that fields were all sorts of shapes rather than neat strips the acre is now any shape you would like it to be. If you’re looking at a tithe map you’ll often see meansurements in acres, roods and perches.
If you just had the one ox rather than a team then an oxgang was the amount that a single oxen could plough in one season – or between 15-20 acres…again the rule of thumb kicks into operation.
And just when you were feeling as though you might be getting a handle on things I’m going to add the fact that in medieval times the unit used for measuring land for taxation purposes and to identify social status was the hide. A hide was deemed sufficient to support one family. Depending where you lived, and the quality of the land, the hide was a movable feast varying between 40 and 1000 acres.
When the Saxons claim to collect tax for Danegeld then worked on the principle of 120 acres = 1 hide. In 1086 when William the Conequer’s Domesday Book was completed the same premise was applied. And just so we’re clear a hide has the same area value as a carucate.
A hundred – an administrative area set up by the Saxons to subdivide a shire was the equally of a hundred hides in size. Across the border into Danelaw the hundred is identified as a wapentake. And of course if a hide supports one family then every hundred would be capable of supplying 100 fighting men – who all presumable arrived with the family rod, perch or pole if they didn’t have a sword or spear.
So from this happy little list of imperial measurements – 12 inches to the foot, 3 feet to the yard, five yards and one foot and six inches to the rod (or pole or perch), 4 rods (or poles or perch) to the chain, 10 chains to the furlong, and 8 furlongs to the statute mile I have omitted a chain.
A chain is 22 yards or 4 rods, poles or perches. A chain is the width of the medieval acre.
And I think that is more than enough for one day- and whichever way you look at it the medieval farmer was required to do an awful lot of walking!