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weights and measures 1. In Greece

(i) Units of weight. In Greece, units of weight had the same names as units of money (since these latter denote weights of metal), thus

6 obols=1 drachma (4.31 g.)

100 drachmas=1 mina (431 g. 454 g. = 1 lb.)

60 minas=1 talent (25.86 kg., about 57 lbs.)

(ii) Units of length. These were based primarily on parts of the human body, with the foot as the fundamental unit. Fractions of a foot and a few longer measures were reckoned in fingers (daktyloi) as follows:

16 fingers=1 pous (foot)

24 ″ = 1 pēchys (cubit, elbow to fingertips)

27 ″ = 1 ‘royal’ cubit

Multiples of feet were:

2½ feet = 1 bēma (pace)

6 ″ = 1 orguia (a stretch of both arms, a fathom)100 ″ = 1 plethron

(An area 100 feet square, the Greek ‘acre’, representing the amount of land which could be ploughed in one day in Greece, was also known as a plethron.) The later Greek unit the stadion (stade) is equivalent to 600 Greek feet; the parasang (parasangēs), consisting of 30 stades, was adopted from Persia.

The Greek foot as used in building measured 294–6 mm. and the Olympic foot (as used in the running track at Olympia) 320 mm. (the modern foot is 305 mm.). The stade may therefore be taken to be 192 m. (210 yards).

2. At Rome

(i) Units of weight. The Roman units of weight were based on the pound, libra (or as), their highest weight, equivalent to 327 g. (about ¾ lb). It was subdivided into 12 ounces (unciae, ‘twelfth parts’, each roughly equivalent to the ounce avoirdupois), and the ounce was subdivided down to the scrīpulum (‘scruple’), its 24th part.

(ii) Units of length. The Roman foot, pes (pl. pedēs), was sometimes divided into 16 fingers (digiti), as in the Greek system but more usually into 12 inches (unciae, ‘twelfth parts’). The other units were:

5 feet = 1 passus (pace)

126 paces = 1 stadium (stade)

1, 000 paces = mille passus, 1 (Roman) mile

The Roman foot measured 296 mm. (about ⅓ inch less than the modern) and the mile 1480 m. (about 140 yards less than the modern mile).

In 1799 France became the first country in the world officially to adopt the metric system (metre, gramme, litre, hectare), although French people continued to use old weights and measures for many years after this. Under the ancien régime many different weights and measures were used in different parts of France, not always with the same meanings. Some of the most frequently encountered are as follows:

Pouce, approx. 1 inch, the twelfth part of a pied.
Pied, a little more than the English foot.
Aune, approx. 1.2 metres (sometimes much less).
Toise, six pieds.
Lieue (cf. English ‘league’), approx. 4 kilometres.
Livre, approx. 1 pound (still used to mean half a kilogramme).
Quintal, 100 livres.
Boisseau, approx. 1 decalitre.
Pinte, a pint.
Setier, between 150 and 300 litres (grain); 8 pints (liquid).
Muid, approx. 268 litres (liquid); 1, 872 litres (dry goods).
Arpent, a little more than one acre.

[Note: many of these terms were used with different meanings in Canada, where the arpent was also a measure of length, approx. 58 metres.]

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Weights and measures throughout Europe during the early modern period were characterized by complexity and confusion and dominated by customary practices. Numbering in the hundreds of thousands, they arose originally from Greek, Roman, Celtic, Germanic, Slavic, and other roots and multiplied on local, regional, and state levels at a rapid pace after 1450. Among the principal causes for this proliferation were economic development, commercial competition, population growth, urbanization, taxation manipulations, territorial expansion, and technological progress. Contributing also were ineffective governmental decrees and legislative acts, the paucity and inferior workmanship of the physical standards manufactured to serve as prototypes, and the overwhelming number of poorly trained officials entrusted with inspection, verification, and enforcement duties.

Central governments contributed to weights and measures proliferation by promulgating multiple state standards for individual units, depending on where they were used and by whom. Sizes of units in capital cities were often different from those in the provinces or in rural areas. They even differed among social classes. On the other hand, common local units occasionally became so popular that they gained unit standardization. They then competed with state units, producing further confusion.

With the rapid growth of cities, weights and measures frequently separated into different standards depending on whether they were employed within the cities or outside their walls. A sharp division arose between urban and suburban measures. Similarly, some measuring units differed according to their use on land or on sea. A general rule throughout Europe was that measures always increased in size or distance once land was no longer in sight.

Product variations were the most important source for metrological proliferation. Those based on quantity measures varied by number or by an odd assortment of human, animal, and other capabilities. Even when these measures had standardized counts, capacities, or weights, the actual sizes depended on the characteristics of the products involved. Compounding this situation was the centuries-old practice of dividing existing units into halves, thirds, and fourths or into an irregular assortment of diminutives. Similar problems were assigning the same name to different units, basing one unit on a multiple or submultiple of another, bestowing more than one name on the same unit, and authorizing various methods of submultiple compilations for a given unit.

Further examples were units of account that were simply computational units for record keeping and other business purposes. Similarly, there were measures reserved for wholesale trade that referred to any number of other better-known units without any correlation to existing standards. Measures were also based on the monetary values of coins, on units of income derived through production, on crop yields and tax assessments, and on work functions, dimensions, and time allotments of humans and animals. The sizes of such units rested on a myriad of imprecise factors.

Regardless of such conditions, Europe in the seventeenth and eighteenth centuries produced a climate of change ushered in by the age of science and the Enlightenment. During this critical period, a number of developments occurred that altered metrological history profoundly, and eventually led to the creation and implementation of the metric system in France in 1793 and the imperial system in England in 1824.

First, there was the dynamic of scientific and technological invention and innovation that overthrew the rigid reliance on past traditions. The introduction of numerous new concepts, instruments, and procedures linked theoreticians with craftsmen for the first time and led to profound advancements in lenses, magnification glasses, microscopes, navigational, astronomical, and triangulation instruments, and clocks. These and hundreds of other breakthroughs, spearheaded chiefly by English, French, and Italian scientists, played a critical role in the reformation of weights and measures.

Second, many of these successes received stimulus and support from the European scientific societies that developed rapidly during the 1600s. By the end of the century, most serious scientists in Europe had become members of these societies, and their journals disseminated knowledge of new discoveries and inventions. In Italy the Roman Accademia dei Lincei and the Florentine Accademia del Cimento made significant scientific strides, the latter especially in its technological apparatus.

The most important societies for the future development of metrology, however, were the Royal Society of London and the Academy of Sciences of Paris and their offshoots, the Greenwich and Paris observatories. The English organizations cast their scientific net far and wide and made giant advancements in physics, astronomy, chemistry, and natural science which, coupled with their pioneering work in technological instruments, helped create a new era in weights and measures. Even more important were the Parisian groups whose scientists introduced the practice of using telescopes in conjunction with graduated circles for the precise measurement of angles. This led to measurements of the meridian arc and the computation of the radius of the Earth. This seminal work provided metrologists with possibilities for a natural physical standard that eventually became the basis for the metric system.

These and other advances led to the creation of hundreds of metrological reform proposals. In England the pendulum was given special emphasis. Since the second unit (of time) is determined by the motion of the earth, it was believed that the length of the second's pendulum in a given latitude would be an invariable quantity that could always be recovered or duplicated. Others proposed altering the existing system to conform to a decimal scale, eliminating all units except for a select few, and coordinating all units to a strict series of ratios. Unfortunately, the revamped English system of 1824 excluded any natural standard and opted only for streamlining the old system and establishing more accurate physical standards. The French proposals concluded far more successfully. After numerous experiments, France settled on a standard determined by the triangulation measurements of that portion of the meridian arc that ran from Dunkirk through Paris to Barcelona. In the process they established a new measure—the meter—as one ten-millionth of the distance from the North Pole to the equator. Even though there eventually were some problems with the final measurements, a new era in world metrology had begun.

Bibliography

Berriman, Algernon E. Historical Metrology. London, 1953. An excellent study of the major issues in European metrological history.

Daumas, Maurice. Scientific Instruments of the Seventeenth and Eighteenth Century. New York, 1972. Shows the impact of technology on numerous metrological developments.

Kula, Witold. Measures and Men. Translated by Richard Szreter. Princeton, 1986. Important for the historical correlation between metrology and society.

Zupko, Ronald E. Revolution in Measurement: Western European Weights and Measures since the Age of Science. Philadelphia, 1990. Extensive coverage of medieval and early modern European weights and measures with a comprehensive bibliography on all issues.

——. "Weights and Measures." In Encyclopedia of the Renaissance. Vol. 6. New York, 1999. Tables of principal European units of measurement.

——. "Weights and Measures: Western European." In Dictionary of the Middle Ages. Vol. 12. New York, 1989. Europe-wide in scope with tables of equivalents; see also author's metrological articles in the other eleven volumes.

—RONALD EDWARD ZUPKO

This entry contains information applicable to United States law only.

A comprehensive legal term for uniform standards ascribed to the quantity, capacity, volume, or dimensions of anything.

The regulation of weights and measures is necessary for science, industry, and commerce. The importance of establishing uniform national standards was demonstrated by the drafters of the U.S. Constitution, who gave Congress in Article 1, Section 8, the power to "fix the Standard of Weights and Measures." During the nineteenth century, the Office of Standard Weights and Measures regulated measurements. In 1901 it became the National Bureau of Standards, and in 1988 it was renamed the National Institute of Standards and Technology.

The states may also regulate weights and measures, provided their regulations are not in opposition to any act of Congress. Legislation that adopts and mandates the use of uniform system of weights and measures is a valid exercise of the police power, and such laws are constitutional. In the early twentieth century the National Bureau of Standards coordinated standards among states and held annual conferences at which a model state law of weights and measures was updated. This effort has resulted in almost complete uniformity of state laws.

Though U.S. currency was settled in a decimal form, Congress has retained the English weights and measures systems. France adopted the metric system in the 1790s, starting an international movement to make the system a universal standard, replacing national and regional variants that made scientific and commercial communication difficult.

Thomas Jefferson was an early advocate of the metric system and in an 1821 report to Congress, Secretary of State John Quincy Adams urged its acceptance. However, Congress steadfastly refused.

Despite hostility to making the metric system the official U.S. system of weights and measures, its use was authorized in 1866. The U.S. also became a signatory to the Metric Convention of 1875, and received copies of the International Prototype Meter and the International Prototype Kilogram in 1890. In 1893 the Office of Weights and Measures announced that the prototype meter and kilogram would be recognized as fundamental standards from which customary units, the yard and the pound, would be derived.

The metric system has been adopted by many segments of U.S. commerce and industry, as well as by virtually all of the medical and scientific professions. The international acceptance of the metric system led Congress in 1968 to authorize a study to determine whether the U.S. should convert. Though the resulting 1971 report recommended shifting to the metric system over a ten-year period, Congress declined to pass appropriate legislation.