Acres, Roods and Perches
Detail from an 1826 survey of
Waltham Abbey, giving areas in Acres, Roods and Perches.
In fact, the terms Poles and Perches were interchangeable;
both referred to the smallest
standard unit of area (5½ yards x 5½ yards) in the Acres - Roods -
Perches system, primarily used for measuring and sub-dividing fields
and land. The word Pole comes from the wooden pole used to measure out its sides, which was
both long enough for a ploughman to prod the oxen in the front row
of his plough-team with, and short enough for the ploughman's boy
to be able to carry it. The alternative Perch might have
derived from the pole being balanced on the boy's shoulder, a bit
like a bird sitting on a branch.
Just to add more confusion, this pole was also
sometimes called a rod, and the Rod also became
the standard unit of length for such things as shop frontages
when a new street was being laid out. In the same way, the two
terms Rod and Rood could also be
confused - especially when old spelling habits are considered. Roods were
usually a unit of
area, equal to 40 Perches (or Poles or Rods - properly
speaking, Square Rods). Unfortunately, however, there was
also a little-used unit of length called a Rood, which was either 7
or 8 yards, or (occasionally) the same as a Rod! Better give up now!
The term Rood is
mostly applied to church features, as it means cross. It's an
old English word which the Anglo-Saxons seem to have brought with
them; it also exists in Old Frisian and Old Saxon (where it meant
'gallows'), Old High German ('rod or pole'), Old Norse ('oar'), and
even Old Slavic (' the shaft of a lance'). From this range of
meanings we can easily see why Rood could be used either for a
length or for an area - or rather (the square of) a length.
Its use within the A.R.P.
system may derive from it
being a quarter of an acre - in other words, an acre cut into four
by making two slices in the form of a cross. This very act of division could even have had
religious significance - perhaps the field was being given a blessing
by being 'crossed' as the land was being divided amongst the
villagers, presumably as it was being cleared of forest and put to
agricultural use for the first time.
Closely related to the Rood
is the Furlong, which was
originally a 'furrow-long' or 'the length of a furrow,'
the length in question being 40 Poles or 220 yards (though doubtless
it was longer in the morning than it was in the evening, when the
oxen were getting tired!). An area
4 Poles wide by 40 Poles (one
furrow-length) long, was considered to be the amount of land that
plough-team (a ploughman, his boy, four pairs of oxen and a long
plough in the daylight hours of one day. This area is referred to as
an Acre, which term derives from an early French word for 'field.'
(The word 'agriculture' has a similar origin - it means 'field
True, the standard
representation of a Rood is not square-shaped, neither is the Acre
from which it is cut; they both (usually!) measure 220 yards (40 Poles, or 1
Furlong) in length, and 5½ yards (1 Pole) or 22 yards (4 Poles)
in width, respectively. Hence the act of division will not have been
in the form of a cross. But this is a mathematical textbook
synthesis of the relationship between the areas, not what happened
'in the field' so to speak, where fields were measured out
with a known length of chain, and were thus very fluid in shape.
Even though ploughing does tend to be done in roughly parallel
lines,the edges of the fields inevitably consisted of curves and odd
shapes. Maybe division by four in itself, regardless of the pattern
of cuts, held spiritual overtones, similar to the axes of a church
Although smaller areas,
subdivisions of the Rood, were more often measured out using the
Pole (a wooden
pole being much cheaper and easier to come by for the average farmer
than an expensive precision-made chain), the use of chains became so
popular that the Chain
also became an official unit of length - but if you see Chains
mentioned on a map-scale, make sure you check the map's context, for
there were many different standard lengths of Chain, such as the
Engineer's Chain (sometimes 50 feet long, sometimes 100).
The Chain which you are
most likely to find used in English surveys and maps however, is
named after Edmund Gunter (1581-1626, a Hertfordshire-born
astronomer-mathematician of Welsh extraction, as his surname
reveals!), which is 4 Poles or 22 yards in length. So why did
Gunter's Chain take off so successfully? What was wrong with Yards
and Poles anyway? They couldn't measure area, that's what.
Remember that an Acre is 22 by
220 yards; by using Gunter's method this becomes 1 x 10 Chains.
Gunter developed this idea further by giving his chain exactly 100
links. This meant that a piece of ground of
any shape could be measured in Chains and tenths (i.e. groups of ten
links) - and in hundredths if
need be; if the length and width are then multiplied together, the result
simply divided by 10 equals the size in Acres!
What Gunter had done was to devise a clever way of calculating areas
in the familiar language of ancient units, by using the simplicity of the decimal system - its
first officially accepted use in England! (Or it is? Answers on a
Although the Chain has
long been obsolete and was always a bit specialist in this country
(being a form of calculation rather than a unit of length), it is
still very much in current use in the U.S.A., being the standard
method of measuring the acreage of all American public lands.
Rods, Roods, Perches and Poles were
all abolished by
the Weights and Measures Act of 1963, though they are still used in
a sense - in cricket, wickets have been placed 22 yards (4 Poles)
ever since 1744, and the numbered posts on racecourses count how
many furlongs away the winning post is. We also still use the
expression 'Oh, we're poles apart!',
'there's a lot of distance or difference between us.' We won't
mention 'spare the rod and spoil the child' - not very P. C. these
Furlongs and Acres, like their
larger cousins Virgates, Hides and Hundreds,
originally varied considerably in size, being measurements of
land-quality (ploughing difficulty) or value (fertility) rather than
physical dimension. But Acres (and by consequence their smaller
divisions) became standardised units of area under an Act
passed by Edward I, and are still a legal unit in England today -
though they are now rarely used officially (except by estate agents)
and are to be repealed in the near future.