Definition:Imperial/Area/Square Rod, Pole or Perch
Definition
The square rod, pole or perch is an imperial unit of area.
One square rod, pole or perch is equal to a square of side $1$ rod, pole or perch in length.
\(\ds \) | \(\) | \(\ds 1\) | square rod, pole or perch | |||||||||||
\(\ds \) | \(=\) | \(\ds 30 \dfrac 1 4 = \paren {5 \dfrac 1 2}^2\) | square yards | |||||||||||
\(\ds \) | \(=\) | \(\ds 272 \dfrac 1 4 = \paren {16 \dfrac 1 2}^2\) | square feet |
Linguistic Note
The rod, pole and perch are all synonyms for the same (archaic) unit of land measurement.
The terms arise from the days of ploughing in mediaeval times.
While the ploughman handled the plough, his assistant controlled the oxen, by means of a stick long enough to reach all the oxen from behind the plough.
This stick was the original rod, pole or perch, and its standard length (from the back of the plough to the front of the oxen) was a convenient way to measure a field.
The word perch derives from the Latin pertica, which itself also means staff or pole.
In modern times, the only time you are likely to see the term rod, pole or perch is in a conversion table, where that is how it is traditionally listed.
Sources
- 1944: Alfred E. Holbrow: Geometrical Drawing (12th ed.) ... (previous) ... (next): Section $\text I$. Introduction
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $30 \frac 1 4$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $30 \frac 1 4$