History of Measurements


1 foot (Latin-pes) = 12 inches (Latin-uncia) since Roman times. History of the Inch An inch was the breadth of a man’s thumb at the base of the nail. To help maintain consistency of the unit, the measure was usually achieved by adding the thumb breadth of three men—one small, one medium, and one large—and then dividing the figure by three. During the reign of King Edward II, 1307-1327, the inch was defined as “three grains of barley, dry and round, placed end to end lengthwise.” At various times the inch has also been defined as the combined lengths of 12 poppyseeds. Since 1959 the inch has been defined officially as 2.54 centimetres. In Anglo-Saxon England, one Ell was 45 inches or 2½ Roman / Viking "cubits". A cubit was an elbow length of 18 inches that in Hebrew was called an "am-mah". The ell continued to be used until recently in the tailoring business when measuring cloth. In Anglo-Saxon England, one garden yard was 5½ ells, or about 20 feet. In 1100, King Henry I redefined a yard as "the distance from his nose to the thumb of his out-stretched arm", the length of a man's belt or girdle, 36 inches or 3 feet. 1 fathom = 6 feet (the length of the outstretched arms). 1 rod, pole, or perch = 5½ yards or 16½ feet. 1 chain = 22 yards or 4 rods. 1 furlong = 220 yards or 40 rods, and the length of a "furrow" in a 10 acre field. 1 Roman mile was originally 1000 paces, and in 1592 it was fixed at 8 furlongs or 1,760 yards. 1 acre = 160 perches (square rods) or 4,840 square yards. 640 acres = 1 square mile.


Precious metals used 12 ounces (Latin-uncia) to a pound (Latin-pondus meaning weight or libra meaning scale), from Roman times. In the German city of Cologne, precious metals were traded at 16 ounces to a pound (Pfund), and 8 ounces to a Mark. In Britain the weight of the ounce was based on a "Tower" scale kept in the Tower of London. 1 Tower ounce = 450 barley grains or just over 29 grams, where 1 barley grain = 64.79891 milligrams. In 1524, the Holy Roman Emperor Charles V declared the Cologne Mark would become the standard weight of all precious metals on the continent (and elsewhere). In 1527, maintaining the British right to be competitive trade-wise both locally and internationally King Henry VIII insisted on all precious metal merchants adopting the Troy ounce probably named after the city of Troyes in north-central France that was one-fifteenth times heavier in weight. 1 Troy ounce = 480 barley grains or just over 31 grams. And this stable "ounce" of silver led to the Austrian/German Thalers ("Dollars"), the Spanish Pesos ("Pieces of Eight") and the slightly heavier English Crowns ("Five Shilling coins"). Click here for more background on these currencies today. When measuring wool and other general goods in Britain, the avoirdupois ("have of weight") system of 7,000 barley grains (16 ounces) to a pound was used. It is still used today in Britain and the US. 1 Avoirdupois Ounce = 437.5 barley grains or just over 28 grams. In Britain, particularly after 1835 when it was formalized, 14 pounds became the standard measure of one stone. The ton was standardized as 20 hundredweight, although the hundredweight could be 100 pounds (short US ton) or 112 pounds based on eight stone (long British ton).


With regards to volume measurements, in 1824 twenty fluid ounces of water was standardized as the measure of a pint (568ml) in England, known as the imperial measure, while the US pint retained its earlier measure of one pound of water or sixteen fluid ounces (473ml). The imperial fluid ounce is about 4% smaller than the US fluid ounce. 1 gallon = 8 pints. 1 bushel = 8 gallons.

France and the Metric System

On the continent, one metre was originally defined in 1791 to be one 10-millionth of the circumferential distance of the Earth from pole to equator, in order that the circumference of the earth could be defined as being exactly 40,000 kilometres. After this theoretical length of the metre was published in 1795, it was subsequently reduced by a very tiny amount in 1799. It has since been found however to be fractionally incorrect, measured around the poles, the earth's circumference is 39,940.653 km (24,817.971 miles). Measured around the equator, it is 40,075.017 km (24,901.461 miles). Still, the length of the metre once it was defined and everyone started using it was left unchanged. 10,000 square metres (100 metres x 100 metres) was defined as a hectare. One gram was defined in Paris in 1795 as the weight of one cubic centimetre of pure water at 4 degrees centigrade which is the temperature of melting ice (the temperature of the maximum density of water). One kilogram of water equals one litre (10 centimetres cubed) in volume. 1,000 kilograms of water (2,204.62 pounds or 1 tonne) equals 1 cubic metre in volume. Thus the gram and the litre which were old Greek and Latin words were now being redefined anew as measuring weight and volume. It also meant one millilitre (mL) was identical with one cubic centimetre (cc) despite some uncertainty. Note too, due to the confusion of misinterpreting ml with m1 (that lower-case l looks very similar to numeric 1), the International System of Units or SI, formed in 1960, accepted the validity of using a capital L in its place.

Now for the history of metrication

History of Metrication Europe converted to the French metric system during the following 80 years. But it wasn't easy. Business people were inconvenienced (and often cheated) due to their lack of familiarity with the system. With insufficient rulers and other measuring tools, Napoleon decreed a "hybrid" system in 1812 for small retail businesses (e.g. where a foot or "pieds" was ⅓ of a metre). But the metric system continued to be taught to children at all levels of education. It was then reinstated in 1840. And having been invaded by France and introduced to the system, Portugal was the second country to officially adopt it in 1814, followed by Belgium, the Netherlands and Luxembourg in 1820, then Switzerland in 1835. The UK were supportive, but insisted that it not be made mandatory, which was also the approach of the US. With French influence and more revolutions, the newly forming Kingdom of Italy adopted the metric system inside Sardinia in 1850, followed by Spain in 1852. In 1856 Bavaria formed a German Customs Union using a 500 gram "pfund" (pound). After Wilhelm I of Prussia was proclaimed German Emperor in 1871, Germany adopted it in 1872. Austria followed shortly after along with Norway in 1875. Turkey Turkey (with its Ottoman Empire) also signed up in 1875, though metrication did not officially occur until after WW1 in 1923. In 1931 international units became compulsory and the traditional units were banned from use in 1933. Palestine (and Israel) With regards to Turkey (which back in 1875 included Palestine), the Ottoman unit of land area was referred to as a dunam, similar to an English acre, representing the amount of land that could be ploughed by a team of oxen in a day. During the early years of the British Mandate for Palestine, the size of a dunam was 9,895 square feet (919.3 square metres), but in 1928, the metric dunam of 1,000 square metres (0.10 hectares) was adopted, and this is what is used in Israel today. Japan Following a revolution in Japan in 1868, and with French assistance, in 1885 Japan signed the Treaty of the Metre, although its use was secondary to Japan's traditional units. Next came Japan's wars inside Russia and occupation of Korea and Taiwan. In 1924, the metre became Japan's legal standard, taught in the schools, though still not compulsory. After WW2, and after the US had occupied Japan and left Japan, the metric system was finally made compulsory in 1961. Russia and China After their revolutions, Russia under Stalin converted to metric in 1925, followed by China under Chiang Kai-Shek in 1930. While Russian insistence on metric was made compulsory in 1927, China's insistence was less so, and the traditional Chinese measurements are still commonly in use today. India introduced the metric system in 1956. Lastly and somewhat peacefully Australia Canada and New Zealand converted in 1971 as those three English speaking countries prepared for computerization.

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