Barleycorn
A barleycorn is an old English unit of length, traditionally based on the length of a grain of barley. It is defined as exactly 1/3 of an inch or approximately 8.47 millimeters.
Historically, the barleycorn was used for measuring small lengths and was also the basis for the inch, which was originally considered to be three barleycorns long. It played a role in various traditional measurements, including shoe sizing in English-speaking countries, where shoe sizes were sometimes expressed in barleycorn units.
Although obsolete as a formal unit, the barleycorn remains culturally significant, especially in shoe sizing systems.
Summary:
1 barleycorn = 1/3 inch ≈ 8.47 mm
Based on the length of a grain of barley
Used historically in small measurements and shoe sizing
Mostly of historical and cultural interest today
Perch
A perch is an old unit of length that is synonymous with the rod or pole, commonly used in land measurement and surveying. It measures 16.5 feet, 5.5 yards, or approximately 5.0292 meters.
The perch was widely used in England and later in the United States for measuring plots of land, especially before the widespread adoption of the metric system. It was also used to describe area when squared (square perch).
Key points:
1 perch = 16.5 feet
1 perch = 5.5 yards
1 perch ≈ 5.0292 meters
4 perches = 1 chain
40 perches = 1 furlong
While largely obsolete today, the term perch still appears in historical land deeds, legal documents, and some traditional surveying contexts.