The bushel is a unit of volume in the imperial unit system with the symbol bsh.
1 bushel is equal to 8 dry gallons, or 36.36872 litres.
The bushel was introduced in England as a unit to bridge the relatively large gap between a pound and a ton - and was used largely to measure volumes of liquid being imported and exported following the Norman Conquest such as wine and ale.
The name bushel comes from the ancient French 'boissiel' which means 'little box'.
The liquid gallon is a unit of volume in the US customary unit system and uses the symbol gal.
It is the most common use of the word gallon and is defined as 231 in³. It is made up of 4 quarts where there are 2 pints in a quart and 16 US fluid ounces in a US pint. There are therefore 128 US fluid ounces in a US gallon.
The term gallon is most prevalent when discussing and trading oil and fuel. To ensure consistency, the temperature of the liquid (typically petroleum or alcohol) is understood to be 15.6 °C (60 °F) at the time of measurement.