Arratel
Encyclopedia
The arratel or arrátel, also referred as libra (pound), was the fundamental unit
of weight
of the ancient Portuguese System of Measurement Units. Until the adoption of the Metric System
in the 19th century, the arratel was used in Portugal
, Brazil
and other parts of the Portuguese Empire
.
The real value of the arratel has undergone changes from the Middle Ages
until it was fixed with the same value as the libra (Iberian pound
), by decree of King Manuel I of Portugal
in 1499. Thereafter, "arratel" has become the alternative official Portuguese designation for the pound.
Fundamental unit
A set of fundamental units is a set of units for physical quantities from which every other unit can be generated.In the language of measurement, quantities are quantifiable aspects of the world, such as time, distance, velocity, mass, momentum, energy, and weight, and units are used to describe...
of weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...
of the ancient Portuguese System of Measurement Units. Until the adoption of the Metric System
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
in the 19th century, the arratel was used in Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
and other parts of the Portuguese Empire
Portuguese Empire
The Portuguese Empire , also known as the Portuguese Overseas Empire or the Portuguese Colonial Empire , was the first global empire in history...
.
The real value of the arratel has undergone changes from the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
until it was fixed with the same value as the libra (Iberian pound
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...
), by decree of King Manuel I of Portugal
Manuel I of Portugal
Manuel I , the Fortunate , 14th king of Portugal and the Algarves was the son of Infante Ferdinand, Duke of Viseu, , by his wife, Infanta Beatrice of Portugal...
in 1499. Thereafter, "arratel" has become the alternative official Portuguese designation for the pound.
Arratel values
- 13th century: Arratel = 12½ onças (ounceOunceThe ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
s) = 25/32 libras = 0,3596 kgKilogramThe kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
; - 15th century: Arratel = 14 onças = 0,4025 kg;
- 1499: Arratel = 16 onças = 1 libra = 1,011 Avoirdupois pound = 0,4590 kg.