Silver Eagle

Log in or Sign up to hide this ad.

Just want to let you know: mintproducts.com does not deliver to other countries than the U.S.

 

Most people don't know what an ounce is. What is commonly thought of as an ounce is 30g but this is an estimation with the advent of the metric system.

A dry weight pound is 454 grams

The rest i lifted from

http://users.aol.com/jackproot/met/spvolas.html#weight

------------------------------------------------------------------------------

Weight
Avoirdupois weight

* 1 grain (= 64.79891 mg) with 7000 grains = 1 pound
* and 16 grains = 1 gram (!) - so 1 "gram" = 1.03678256 g (don't be confused)
* 27.34375 grains = 1 dram (= 1.771845195 g)
* 16 dram = 1 ounce (= 28.34952313 g) therefore 437.5 grains = 1 ounce
* 16 ounces = 1 pound (= 453.59237 g - exact weight since July 1, 1959)
* 14 pounds = 1 stone (= 6.3503 kg) - yes, you read 14, not 12 nor 16 - used in UK only
* 2 stones = 1 British quarter (= 12.701 kg)
* but the US quarter was equal to 25 pounds (= 11.34 kg)

We have automatically a difference with the next unit : the hundredweight or cwt. :

* in England, 1 hundredweight is 4 British quarters or 112 pounds (= 50.802345 kg)
* in the US, 1 hundredweight is 4 US quarters or 100 pounds (= 45.359237 kg)

As 1 ton is equal to 20 hundredweights, this leads to 2 different tons :

* the British long ton (= 2240 lb or 1016.0469 kg)
* the US short ton (= 2000 lb or 907.18474 kg)

Pound history : see under "Troy"
Avoirdupois in French means "to have weight" or "goods of weight" by extension
- used for commercial operations.

The flask is still used, essentially as the selling unit for mercury = 76 pounds (Avoirdupois) or 34.473 kg in UK - but 75 pounds in the US !

Let's mention a unit I love : the kip or kilopond (= 1000 lbs, of course, but generally used as a unit of force.) -- Beware : in the US, it is used sometimes as "kilogram-force" ! Just what we needed to simplify the system.

Other old English units :

* 1 quartern = 4 lbs
* 1 block = 5 lbs
* 1 head = 6 3/4 lbs
* 1 clove or brick = 7 lbs
* 1 gallon = 10 lbs (makes sense considering the definition of the Imperial gallon)
* 1 score = 20 lbs
* 1 truss (straw) = 36 lbs
* 1 frail = 50 lbs
* 1 firkin = 56 lbs or 2 quarters
* 1 bushel = 63 lbs
* 1 tub = 84 lbs
* 1 box = 90 lbs
* 1 fagot or seam = 120 lbs (fagot is used for iron and steel - seam for glass)
* 1 sack = 168 lbs (= 2 tubs - used for coal, potatoes - different meaning for other materials)
* 1 wey = 182 lbs
There are several other units (pack, pig, tierce, bag, bale, cask, fodder, ...) but quite often they mean different weights according to the material being measured. Call if you have a specific question.

Troy weight

* the same grain (= 64.79891 mg)
* 24 grains = 1 pennyweight or dwt. (= 1.55517384 g)
* 20 pennyweights = 1 ounce Troy (= 31.1034768 g or 480 grains)
* 12 ounces Troy = 1 pound Troy (= 5760 grains or 373.2417216 g)

Note : there was also an Imperial carat (1877) equal to 3.168 grains or 0.2053 g and a metric carat equal to 0.2 g.
The old carat is sometimes defined as 4 grains, which gives 0.2592 g but that's a mistake : in fact, it was equal to 4 "pearl grains", a somewhat smaller unit also called a quarter or a carat grain (these were real seeds !)

Another meaning of carat or karat is the analysis of precious metals as alloys, in twenty-four parts.
Example : a 22 carat gold contains 22/24 gold or 91.7 %, the remaining being generally silver.

Note : in England, the Troy pound was abolished on Jan. 6, 1879.
Only the Troy ounce and its subdivisions were retained.

Detail : The name Troy, used for weighing precious metals, is derived from the city of Troyes (Champagne - France) where the system is thought to have originated : they had a well known commercial fair throughout the Middle Ages.
Anecdote : the pennyweight was also defined in 1266 by Henry III as the weight of 32 wheatcorns taken in the middle of the ear. NB : for 24 grains, what species ?
In monetary terms, a Troy pound of silver gave its name to the Sterling pound, subdivided into 20 shillings or 240 pence (pennyweights).

Historically the pound derives from the Roman libra (hence the abbreviation "lb") whose weight was anything between 4944 and 5220 grains.
("Libra" meant a weight or a balance - it survives in the expression "equal weights" - equilibrium).
It was subdivided into 12 unciae or ounces.
NB : the abbreviation "oz" seems to have come from the Italian "onza" - meaning ounce, of course.

The oldest standard in England, the Saxon pound, became known as the Tower pound because it was kept in the Tower of London and weighed 5400 grains. Henry VIII replaced it with the Troy pound in 1527, ordering that an ounce be 480 grains and not any more 450 grains. (The "pounde Troye which exceedeth the pounde Tower in weight iii quarters of the oz." Meaning that the difference between the two pounds was 360 grains or 3/4 of a new ounce.) He made the new Troy pound the official standard for minting coins.
Note : no surprise, a heavier mint reference means more taxes !

Over the centuries the old Saxon pound had been used in parallel with a variety of foreign pounds (french, it seems) in everyday business. The most successful one - avoirdupois - was "assimilated" as having 15 Troy ounces of today (16 Troy oz of that time), therefore 7200 grains. Henry VIII brought it down to 7000 grains to be divided into 16 "special" ounces and later Elizabeth I prohibited all other "merchant" pounds.

Note : in France, the merchant pounds were often already divided into 16 ounces.
In Paris, 1 once had 576 grains but the grain was lighter (about 53.1 mg vs 64.8 mg for the English grain).
It should be noted that this once was very close to the Troy ounce : only 1.7 % difference.

Standards were kept in the House of Parliament and shared their history with the length units (destroyed by fire in 1834 - new standards from preserved copies in 1845.)

The US pound has always been more or less similar to the avoirdupois pound. In 1830, the Senate ordered an inspection in the customhouses and uncovered quite a variety of "standards". In the following years, new standards were dispatched to the customhouses and to the governor of each state, based on 7000 / 5760 of the new Troy pound received recently and adopted in 1828 as the official Mint reference.
The US pound is officially defined as a fraction of the kilogram since 1889.

On July 1, 1959, all English speaking countries decided to average off their differences and adopt an Avoidupois pound weighing exactly 453.59237 g. (There was actually very little change, but in the last couple of decimals.)

Other old units :

* 1 mite = 1/20 grain
* 1 mancus = 2 ounces
* 1 merchant pound = 7680 grains (very close to the last french pound preceding the metric system)
* 1 mast = 2.5 Troy pounds

Apothecaries weight
Based on the Troy system

* 20 (same) grains or minims = 1 scruple (1 scruple = 1.2959782 g)
* 3 scruples = 1 drachm (dr ap) or dram in the US (= 3.8879346 g)
* 8 drachms = 1 ounce Troy

 

http://ts.nist.gov/ts/htdocs/230/235/appxc/appxc.htm