Coomb (unit)

A coomb is a measure of volume. Its exact original details are not known. In 13th century England it was defined as 4 bushels. It was in use in Norfolk as a dry measure: "Ben sold my Wheat to the Marlingford Miller this Morning for 19 shillings per Coomb" – Parson Woodforde's Diary, 20 May 1786. The 4-bushel bag was the standard international shipping unit for grain, and the coomb was in common use in farming in Norfolk and Suffolk until well after the end of World [War II], in fact for as long as grain was handled in sacks, a practice which ended with the introduction of combine harvesters which had bulk grain tanks.
Yields were referred to in coombs per acre. A coomb was for barley and for wheat.
The US grain markets quote prices as cents per bushel, and a US bushel of grain is about, which would approximately correspond to the 4-bushel coomb.