A two-part petition from J. F. Cosnahan to the Duke of Atholl dated March 1817, seeking intercession with the Prince Regent for remission of John Bean Hannay's seven-year transportation sentence for violation of slave trade abolition acts. Hannay, a young Manxman, had assisted in transporting slaves whilst serving as mate and later captain of a vessel. The petition emphasizes his youth, inadvertence, and family hardship (widowed mother with six daughters; loss of his brother at sea). A second letter follows, noting plans for a petition signed by Liverpool merchants. Includes genealogical and contextual annotations identifying the Hannay family and related individuals.