I'm going to try to write a summary about the mainly Angloxason weight meusare units. It's truth that I could write about the Angloxason measure units in general, but I only want to focalize on the weight measures.
Some Commonwealth countries or territories like UK, USA, Canada, Australia, Ireland, India, Malaysia, Hong Kong, or some Caribean islands or countries, still use nowadays different weight measures instead of the international standards, mainly in some rural or particular situations, but also, in some cases, as the mainly or unique unit, for instance, the weight of a person, or vegetables or fruits in USA, is usually referred to as pounds ("lb" or "lbs").
The use of different measure and weight systems depending on the purpose was an almost universal phenomenon in Europe between the decline of the Roman Empire and metrication.
There are some systems of measure units, two (avoirdupois and troy) of them are still used nowaday, others were abolished or are rarely used. We' ll see a brief of each of them:
- Avoirdupois: Is a system of weights (or, properly, mass) based on a pound of 16 ounces. It is the everyday system of weight used in the United States and is still widely used to varying degrees by many people in Canada, the United Kingdom, and some other former British colonies despite the official adoption (or partial adoption in the case of the UK) of the metric system.
| Unit | Original form relative value | British adaptation relative value | British adaptation metric value | American customary system relative value | American customary relative value metric value |
| grain (gr) | 1⁄7000 lb | ±64.80 mg | |||
| "part" | 1/256 (1⁄16 once) | ||||
| dram or drachm (dr) | 1⁄256 (1⁄16 once) | ±1.772 g | 1⁄256 | ±1.772 g | |
| ounce(oz) | (once) 1⁄16 | 1⁄16 | ±28.35 g | 1⁄16 | ±28.35 g |
| pound (lb) | (livre) 1 | 1 | ±453.6 g | 1 | ±453.6 g |
| stone (st) | (pere) 14 | 14 | ±6.350 kg | ||
| quarter (qtr) | 28 | ±12.70 kg | 25 | ±11.34 kg | |
| hundredweight (cwt) | 112 | ±50.80 kg | 100 | ±45.36 kg | |
| sak de leine (woolsack) | 364 | ||||
| ton (t) or long ton (l. tn.) | 2,240 | ±1,016 kg | 2,000 | ±907.2 kg |
It's believed that this units have its origin in their Anglo-Norman French forms.
- Troy weight: it's a system of units of mass that has been focused for precious metals, gemstones, and black powder.
It's origins could be from the trading with the French town of Troyes where the English merchants traded at least as the early 9th century.
One of the reasons for the success of this measure unit, was the lack to use the standards with international commerce, and the use of this unit for that purpose.
In the 19th century, most European countries or cities still had at least a "commercial" or "civil" system (such as the English avoirdupois system) for general trading, and a second system (such as the troy system) for precious metals such as gold and silver.
One of the reasons for the success of this measure unit, was the lack to use the standards with international commerce, and the use of this unit for that purpose.
In the 19th century, most European countries or cities still had at least a "commercial" or "civil" system (such as the English avoirdupois system) for general trading, and a second system (such as the troy system) for precious metals such as gold and silver.
| Unit | Relative value | Metric value |
| Troy pound (troy) | 12 troy ounces | ±373'2417216 g |
| Troy ounce (oz t) | 20 pennyweights | ±31'1034768 g |
| Pennyweight (dwt) | 24 grains | ±1'55517384 g |
| Troy grain (grain) | 1 | ±0'06479891 g |
Tower pound: The tower system was referenced to a standard prototype found in the Tower of London and ran concurrently with the avoirdupois and troy systems, until it fell out of use and was abolished in 1527.
A tower pound is equivalent to about 350 grams. And it's niche was the same as the troy: jewellery and precious metals.
| Unit | Relative value | Relative value (with troy) | Metric value |
| 1 mercantile pound(15 oz) | 9600 tower grains | 6750 troy grains | ±437'5 g |
| 1 tower pound (12 oz) | 7680 tower grains | 5400 troy grains | ±350 g |
| 1 tower ounce (20 dwt) | 640 tower grains | 450 troy grains | ±29'16666 g |
| 1 tower pennyweight (dwt) | 32 tower grains | 22½ troy grains | ±1'458333 g |
- Apothecary: The apothecaries' system of weights is a historical system of mass units that were used by physicians and apothecaries for medical recipes, and also sometimes by scientists.
This exact form of the system was used in the United Kingdom; in some of its former colonies it survived well into the 20th century. The apothecaries' system of measures is a similar system of volume units based on the fluid ounce.
For a long time, medical recipes were written in Latin, often using special symbols to denote weights and measures.
For a long time, medical recipes were written in Latin, often using special symbols to denote weights and measures.
- Other: There have been other types of measure units, here I list some of them:
- Merchants/Mercantile pound.
- London/Mercantile pound.
- Mercantile stone.
- Butcher's stone.
- Sack.
Some references:
- http://www.unc.edu/~rowlett/units/
- http://en.wikipedia.org/wiki/English_units
- http://en.wikipedia.org/wiki/Imperial_units
- http://en.wikipedia.org/wiki/Avoirdupois
- http://en.wikipedia.org/wiki/Troy_weight
- http://en.wikipedia.org/wiki/Pound_%28mass%29#Tower_pound
- http://en.wikipedia.org/wiki/Apothecaries%27_system
It seems such an interesting entry to people who can understand this concepts. Congratulations for the blog. :D
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