This derivation of the Vitruvian Man by Leonardo da Vinci, depicts nine historical units of measurement: the Yard, the Span, the Cubit, the Flemish Ell, the English Ell, the French Ell, the Fathom, the Hand , and the Foot. The Vitruvian man was drawn to scale, so the units depicted are displayed with their proper historical ratios.

A yard (abbreviation: yd) is the name of a unit of length in a number of different systems, including English units, Imperial units, and United States customary units. Its size can vary from system to system. The most commonly used yard today is the international yard which by definition is equal to 0.9144 metre.

The yard is used as the standard unit of field length measurement in both the American and Canadian games of football (although Canada has officially adopted the metric system).

The yard is used on road signs and markers in the UK. Indeed, it is illegal to display length/speed in metres/kilometres on road signs in the UK, as this would cause confusion.

A corresponding unit of area is the square yard.

Yard is also a slang word, used particularly in currency trading, for one billion units of a currency, e.g., a yard of dollars is $1bn, thus a buyer of a billion dollars could say "I\'m a buyer of a yard of dollars."Bloomberg.com: Financial Glossary

Equivalence to other units of length

1 international yard is equal to:

• 0.5 fathom (1 fathom is equal to 2 yards)
• 3 feet (1 foot is a third of a yard)
• 36 inches
• 0.9144 metre (1 metre is equal to about 1.0936 international yards)

The early yard was divided by the binary method into two, four, eight, and sixteen parts called the half-yard, span, finger, and nail. Two yards are a fathom.

Etalons on the wall of Royal Observatory Greenwich, London, Great Britain depicting length measures - 1 yard (3 feet), 2 feet, 1 foot, 6 inches (1/2 foot), and 1 inch.

Historical origin

The yard derives its name from the word for a straight branch or rod, although the precise origin of the measure is not definitely known. Some believe it derived from the double cubit, or that it originated from cubic measure, others from its near equivalents, like the length of a stride or pace. One postulate was that the yard was derived from the girth of a person\'s waist, while another claim held that the measure was invented by Henry I of England as being the distance between the tip of his nose and the end of his thumb. These are believed to be more likely standardising events than inventing of the measure.^{[citation needed]}

References

See also

• English unit
• Imperial unit
• Guz, the yard of the Middle East
• United States customary units
• Vara

This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia

This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia