the.com/fluid ounce
A volume that picked a fight with weight and confused everyone for centuries.
twin unitsUS and UK fluid ounces are different sizes.
volume not weightMeasures space, despite sounding like the scale unit.
odd ratioA US gallon holds exactly 128 fluid ounces.
old rootsDescends from the Roman uncia, meaning one-twelfth.
the gapUK ounce is about 4 percent bigger.