Originally weight was based on grains, for example, in thirteenth-century England, a pound was equal to twelve ounces which equated to 437 grains of barley. However prior to the standardisation of weights and measures in 1824, there were a variety of differences in what was supposed to be the same weight. There were regional variations as well as different sizes depending on what you were measuring. One example is the gallon, for which there was an ale gallon, wine gallon and corn gallon, all of which were different sizes.
The Weights and Measures Act of 1824 sought to standardise weights and measures and deal with the complications this variety introduced. This alongside a second act in 1878 would introduce the Imperial system.
This Imperial system gave three different groups of units for use with different objects. The Avoirdupois was the most common form of measurement for standard items. Troy Ounces, which are still in use, were for use in measuring precious metals or gemstones. Apothecaries was a version of the Troy Ounce for use by pharmacists in measuring powders.
Confusingly, however, this system measured many items by volume, whilst we would now think of measuring them by weight. For instance in milling and grain some of the most common measurements were:
- Two Pints to one Quart
- Four Quarts to one Gallon
- Two Gallons to one Peck
- Four Pecks to One Bushel