Definition:Imperial/Area/Acre
< Definition:Imperial | Area(Redirected from Definition:Acre)
Jump to navigation
Jump to search
Definition
The acre is an imperial unit of area.
One acre is equal to an oblong measuring $1$ chain by $1$ furlong.
That is, measuring $4$ rods, poles or perches by $10$ chains.
| \(\ds \) | \(\) | \(\ds 1\) | acre | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4\) | roods | |||||||||||
| \(\ds \) | \(=\) | \(\ds 10\) | square chains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 160 = 4 \times 40\) | square rods, poles or perches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4840 = 22 \times 220\) | square yards | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 0 \cdotp 4\) | hectares |
Historical Note
The acre is a traditional measure of land arising from the days of ploughing in mediaeval times and earlier.
It was defined as the area of land that could be ploughed by $1$ ploughman with $1$ ox in $1$ day.
It is noted that an acre is not actually defined as a square area, but as an oblong strip $10$ times as long as it is wide.
The reason is readily apparent: its length is, as is apparent from its definition, one furlong, that is, furrow-long.
Linguistic Note
The word acre derives from the Old English æcer, meaning open field.
It is pronounced ay-ker, and was at one time spelt aker.
Sources
- 1944: Alfred E. Holbrow: Geometrical Drawing (12th ed.) ... (previous) ... (next): Section $\text I$. Introduction
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $4840$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $4840$
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): acre