The size and weight of a barrel varied and was often dependent on whether the contents were liquid or solid. In the United States, statutes generally regulated that a barrel should contain 28 to 31½ gallons. (“Barrel,” in American Dictionary [1828].)

An American Dictionary of the English Language: Intended to Exhibit, I. the Origin, Affinities and Primary Signification of English Words, as far as They Have Been Ascertained. . . . Edited by Noah Webster. New York: S. Converse, 1828.

Newel K. Whitney added an asterisk here, which corresponds to an endorsement written on the second page, which reads:"1 Bbll was Summer oil."

A small cask or barrel, varying in size but usually containing less than ten gallons. (“Keg,” in American Dictionary [1828]; “Keg,” in Oxford English Dictionary, 5: 667.)

An American Dictionary of the English Language: Intended to Exhibit, I. the Origin, Affinities and Primary Signification of English Words, as far as They Have Been Ascertained. . . . Edited by Noah Webster. New York: S. Converse, 1828.

The Oxford English Dictionary. Edited by James A. H. Murray, Henry Bradley, W. A. Craigie, and C. T. Onions. 12 vols. 1933. Reprint, Oxford: Oxford University Press, 1970.