Search results
Results From The WOW.Com Content Network
A pennyweight (dwt) is a unit of mass equal to 24 grains, 1 ⁄ 20 of a troy ounce, 1 ⁄ 240 of a troy pound, approximately 0.054857 avoirdupois ounce [1] and exactly 1.55517384 grams. [2] It is abbreviated dwt , d standing for denarius – (an ancient Roman coin), and later used as the symbol of an old British penny (see £sd ).
The troy weight units are the grain, the pennyweight (24 grains), the troy ounce (20 pennyweights), and the troy pound (12 troy ounces). The troy grain is equal to the grain unit of the avoirdupois system, but the troy ounce is heavier than the avoirdupois ounce, and the troy pound is lighter than the avoirdupois pound. Legally, one troy ounce ...
In either case, a London bushel was reckoned to contain 64 pounds, 12 ounces, 20 pennyweight, and 32 grains. These measures were based on the relatively light tower pound and were rarely used in Scotland, Ireland, or Wales during the Middle Ages.
Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10 −6 metre).
Another difference arose when Britain abolished the troy pound (373.241 7216 g) on 1 January 1879, leaving only the troy ounce (31.103 4768 g) and its decimal subdivisions, whereas the troy pound (of 12 troy ounces) and pennyweight are still legal in the United States, although they are no longer widely used.
In the evolutionary approach, the foot was to be derived from these lengths by a simple integer factor, which would be either three (pendulum) or five (rod), i.e. lengthening it from the traditional value of about 304 mm by slightly over 1 inch to ca. 331 mm or shortening it by about a quarter of an inch to ca. 298 mm.
For example, 1 troy ounce of 18 karat gold (which is 750 ‰ gold) may be said to have a fine weight of 0.75 troy ounces. Most modern government-issued bullion coins specify their fine weight. For example, the American Gold Eagle is embossed One Oz. Fine Gold and weighs 1.091 troy oz.
The teaspoon, tablespoon, and cup are defined in terms of a fluid ounce as 1 ⁄ 6, 1 ⁄ 2, and 8 fluid ounces respectively. The fluid ounce derives its name originally from being the volume of one ounce avoirdupois of water, [21] but in the US it is defined as 1 ⁄ 128 of a US gallon. Consequently, a fluid ounce of water weighs about 1.041 ...