|This page uses content from the English Wikipedia. The original article was at Pound (mass)#Avoirdupois pound. The list of authors can be seen in the page history. As with the Units of Measurement Wiki, the text of Wikipedia is available under Creative Commons License see Wikia:Licensing.|
The avoirdupois pound, also known as the wool pound, first came into general use c. 1300. It was initially equal to 6992 troy grains. The pound avoirdupois was divided into 16 ounces. During the reign of Queen Elizabeth, the avoirdupois pound was redefined as 7,000 troy grains. Since then, the grain has often been considered as a part of the avoirdupois system. By 1758, two Elizabethan Exchequer standard weights for the avoirdupois pound existed, and when measured in troy grains they were found to be of 7,002 grains and 6,999 grains.
Comparison of different English pounds
|Metric||1||≈ 15/14||≈ 11/10||≈ 8/7||≈ 4/3||≈ 10/7||≈ 16||≈ 171/7||≈ 173/5||≈ 7716||≈ 10974||500||1/2|
|London||≈ 14/15||1||36/35||16/15||5/4||4/3||15||16||1616/35||7200||10240||≈ 467||≈ 7/15|
|Avoirdupois||≈ 10/11||35/36||1||28/27||175/144||35/27||147/12||155/9||16||7000||99555/9||≈ 454||≈ 9/20|
|Merchant||≈ 7/8||15/16||27/28||1||75/64||5/4||141/16||15||153/7||6750||9600||≈ 437||≈ 7/16|
|Troy||≈ 3/4||4/5||144/175||64/75||1||16/15||12||124/5||1329/175||5760||8192||≈ 373||≈ 3/8|
|Tower||≈ 7/10||3/4||27/35||4/5||15/16||1||111/4||12||1212/35||5400||7680||≈ 350||≈ 7/20|
- ↑ Skinner, F.G. (1952). "The English Yard and Pound Weight". Bulletin of the British Society for the History of Science 1 (7): 184–6. doi:10.1017/S0950563600000646.
- ↑ United States. National Bureau of Standards (1962). weights and measures. Taylor & Francis. pp. 22–24. GGKEY:4KXNZ63BNUF. http://books.google.com/books?id=ycgOAAAAQAAJ&pg=PA22. Retrieved 26 December 2011.