A Dictionary of Units of Measurement is a fascinating compendium of information. Yeah, I know, it sounds dry, but if you are a word-lover, this will be right up your alley. How many websites discuss German beer measurements, the measuring of solar flare intensity, tennis racquet gauges, and the definition of “smidgen,” all in one place?
Some examples of what can be found there:
mease: a unit of quantity formerly used by fishermen. The mease equals the number of herring in a basket, roughly 620.
donkey power: a somewhat light-hearted metric unit of power equal to 250 watts or about 0.3353 horsepower.
luster, lustre, lustrum: a traditional unit of time equal to 5 years. In ancient Rome the Lustrum was ceremony of expiation and purification for the whole population of the city, carried out every 5 years after the completion of the census. The use of luster or lustrum as a unit of time in English was fairly common in well-educated circles as long as “well-educated” meant classically educated; the unit has pretty much disappeared today.