A tron was a weighing machine in medieval Scotland

Kingdom of Scotland

The Kingdom of Scotland was a Sovereign state in North-West Europe that existed from 843 until 1707. It occupied the northern third of the island of Great Britain and shared a land border to the south with the Kingdom of England...

, usually located in the marketplaces of burgh

Burgh

A burgh was an autonomous corporate entity in Scotland and Northern England, usually a town. This type of administrative division existed from the 12th century, when King David I created the first royal burghs. Burgh status was broadly analogous to borough status, found in the rest of the United...

s. There are various areas of several Scottish towns that are named for them. Etymologically the word is derived from the Old French

Old French

Old French was the Romance dialect continuum spoken in territories that span roughly the northern half of modern France and parts of modern Belgium and Switzerland from the 9th century to the 14th century...

 tronel or troneau, meaning "balance".

Measurement of weight in medieval Scotland

From the 12th century the city fathers of Scottish burghs needed to standardise weights and measurements, partly to collect the correct taxation on goods, and partly to stop unscrupulous merchants shortchanging citizens. Trons were set up in marketplaces throughout Scotland, with each burgh with its own set of, sometimes differing, weights. Some burghs had more than one tron; in Edinburgh

Edinburgh

Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...

 a butter tron was located at the head of the West Bow, while a salt tron was located further down the Royal Mile

Royal Mile

The Royal Mile is a succession of streets which form the main thoroughfare of the Old Town of the city of Edinburgh in Scotland.As the name suggests, the Royal Mile is approximately one Scots mile long, and runs between two foci of history in Scotland, from Edinburgh Castle at the top of the Castle...

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