What practical frustration characterized weights and measures before the metric system in Europe?

The definition of units like 'foot' or 'pound' changed frequently, even within the same city or guild.

Prior to the late 18th century, the system of weights and measures across Europe, especially in France, was characterized by extreme inconsistency and chaos. This meant that a standard unit, such as a 'foot' or a 'pound,' could possess entirely different values depending on the specific town, region, or even the particular guild conducting the transaction. This utter lack of uniformity severely hindered fair trade by breeding distrust between parties, made large-scale commerce unpredictable, and posed significant obstacles to accurate scientific collaboration across different geographical or institutional boundaries. The primary motivation for the revolutionary project was to replace this localized, arbitrary system with one rooted in universal, immutable standards dictated by reason.