The Penny Cyclopædia of the Society for the Diffusion of Useful Knowledge was a multi-volume encyclopedia edited by George Long and published by Charles Knight alongside the Penny Magazine. Twenty-seven volumes and three supplements were published from 1828 to 1843.
The unnamed contributors to the Penny Cyclopædia included many notable figures of the period, including the librarian Henry Ellis, the biblical scholar John Kitto, the publisher Charles Knight, the critic George Henry Lewes, the mathematician Augustus De Morgan, the surgeon James Paget, the statistician George Richardson Porter, the sanitary reformer Thomas Southwood Smith, and the art historian Ralph Nicholson Wornum.
In popular culture
The novelist Herman Melville is known to have used the Penny Cyclopædia while writing Moby-Dick and other novels, and scholar Paul McCarthy has suggested that the encyclopedia's coverage of moral insanity and monomania may have influenced Melville's characters in Moby-Dick and other writings.
- Baker, William (September 1974). "George Henry Lewes and the 'Penny Cyclopaedia': Twenty-Seven Unattributed Articles". Victorian Periodicals Newsletter 7 (3): 15–18. Retrieved 6 December 2013.
- McCarthy, Paul (1987). "Forms of Insanity and Insane Characters in Moby-Dick". Colby Quarterly 23 (1): 1–14. Retrieved 6 December 2013.