Editing Weighing scale (section)

===History===
[[File:El pesado del corazón en el Papiro de Hunefer.jpg|thumb|The Ancient Egyptian ''[[Book of the Dead]]'' depicts a scene in which a scribe's heart is weighed against the [[Maat|feather of truth]].]]
The balance scale is such a simple device that its usage likely far predates the evidence. What has allowed archaeologists to link artifacts to weighing scales are the stones for determining absolute mass. The balance scale itself was probably used to determine relative mass long before absolute mass.<ref name="averyweigh-tronix1947"/>

The oldest attested evidence for the existence of weighing scales dates to the [[Fourth Dynasty of Egypt]], with [[Deben (unit)]] balance weights, from the reign of [[Sneferu]] (c. 2600 BC) excavated, though earlier usage has been proposed.<ref>{{Cite journal |last=Rahmstorf |first=Lorenz |title=In Search of the Earliest Balance Weights, Scales and Weighing Systems from the East Mediterranean, the Near and Middle East |url=https://www.academia.edu/1864503}}</ref> Carved stones bearing marks denoting mass and the Egyptian hieroglyphic symbol for gold have been discovered, which suggests that Egyptian merchants had been using an established system of mass measurement to catalog gold shipments or gold mine yields. Although no actual scales from this era have survived, many sets of weighing stones as well as murals depicting the use of balance scales suggest widespread usage.<ref name="jstor44" />

Examples, dating  {{circa|2400–1800 BC}}, have also been found in the [[Indus Valley civilisation|Indus River valley]]. Uniform, polished stone cubes discovered in early settlements were probably used as mass-setting stones in balance scales. Although the cubes bear no markings, their masses are multiples of a common denominator. The cubes are made of many different kinds of stones with varying densities. Clearly their mass, not their size or other characteristics, was a factor in sculpting these cubes.<ref name="jstor44">{{cite journal|author=Petruso, Karl M|title=Early Weights and Weighing in Egypt and the Indus Valley  |journal=M Bulletin |volume=79|year=1981|pages=44–51|jstor=4171634}}</ref>

In China, the earliest weighing balance excavated was from a tomb of the [[state of Chu]] of the Chinese [[Warring States period]] dating back to the 3rd to 4th century BC in Mount Zuojiagong near [[Changsha]], Hunan. The balance was made of wood and used bronze masses.<ref>{{Cite book |title=Ancient Engineers' Inventions: Precursors of the Present (History of Mechanism and Machine Science) |last1=Rossi |first1=Cesare  |last2=Russo  |first2=Flavio  |last3=Russo  |first3=Ferruccio  |year=2009 |isbn=978-9048122523 |publication-date=May 11, 2009 |page=21|publisher=Springer }}</ref><ref>{{Cite book |title=Reconstruction Designs of Lost Ancient Chinese Machinery |last= Yan |first=Hong-Sen |publisher=Springer |year=2007 |publication-date=November 18, 2007 |pages=53–54}}</ref>

Variations on the balance scale, including devices like the cheap and inaccurate ''bismar'' (unequal-armed scales),<ref>{{cite web|url=http://www.isasc.org/Tutorial/Scale-Types.html |title=ISASC |publisher=ISASC |access-date=2014-02-26}}</ref> began to see common usage by c. 400 BC by many small merchants and their customers. A plethora of scale varieties each boasting advantages and improvements over one another appear throughout recorded history, with such great inventors as Leonardo da Vinci lending a personal hand in their development.<ref name="averyweigh-tronix2">{{cite web|url=http://www.averyweigh-tronix.com/main.aspx?p=1.1.3.4 |title=The History of Weighing |publisher=Averyweigh-tronix.com |date=2012-03-02 |access-date=2014-03-05 |url-status=dead |archive-url=https://web.archive.org/web/20120302145347/http://www.averyweigh-tronix.com/main.aspx?p=1.1.3.4 |archive-date=March 2, 2012 }}</ref>

Even with all the advances in weighing scale design and development, all scales until the seventeenth century AD were variations on the balance scale.  The standardization of the weights used – and ensuring traders used the correct weights – was a considerable preoccupation of governments throughout this time.

<gallery widths="200px" heights="200px" class="center">
File:Archaeological site of Akrotiri - Museum of prehistoric Thera - Santorini - weighing dishes - 01.jpg|Weighing dishes from the island of [[Thera]], [[Minoan civilization]], 2000–1500 BC
File:Lionweights-BM.JPG|[[Assyrian lion weights]] (8th century BC) in the [[British Museum]]
File:Weegschaal (unster) met 2 gewichten in brons, 50 tot 200 NC, vindplaats- Onbekend, collectie Gallo-Romeins Museum Tongeren, GRM 48.jpg|Roman [[steelyard balance]] with two bronze weights, 50–200 AD, [[Gallo-Roman Museum, Tongeren]], Belgium
File:Meister der Jahângîr-Memoiren 001.jpg|Emperor [[Jahangir]] (reigned 1605–1627) weighing his son [[Shah Jahan]] on a weighing scale by artist [[Manohar Das|Manohar]] (AD 1615, Mughal dynasty, India)
</gallery>
The original form of a balance consisted of a beam with a fulcrum at its center. For highest accuracy, the fulcrum would consist of a sharp V-shaped pivot seated in a shallower V-shaped bearing. To determine the mass of the object, a combination of reference masses was hung on one end of the beam while the object of unknown mass was hung on the other end (see [[balance (ability)|balance]] and [[steelyard balance]]). For high precision work, such as empirical chemistry, the center beam balance is still one of the most accurate technologies available, and is commonly used for calibrating test masses.

However, bronze fragments discovered in central Germany and Italy had been used during the [[Bronze Age]] as an early form of currency.<ref>{{cite journal |last1=Ialongo |first1=Nicola |last2=Lago |first2=Giancarlo |title=A small change revolution. Weight systems and the emergence of the first Pan-European money |journal= Journal of Archaeological Science|year=2021 |volume=129 |page=105379 |doi=10.1016/j.jas.2021.105379 |bibcode=2021JArSc.129j5379I |doi-access=free |hdl=11573/1547061 |hdl-access=free }}</ref> In the same time period, merchants had used standard weights of equivalent value between 8 and 10.5 grams from Great Britain to Mesopotamia.<ref>{{cite journal |last1=Ialongo |first1=Nicola |last2=Hermann |first2=Raphael |last3=Rahmstorf |first3=Lorenz |title=Bronze Age weight systems as a measure of market integration in Western Eurasia |journal=PNAS |year=2021 |volume=118 |issue=27 |pages=e2105873118 |doi=10.1073/pnas.2105873118 |pmid=34183401 |pmc=8271817 |bibcode=2021PNAS..11805873I |doi-access=free }}</ref>