Unpublished letter, on Henry Smeathman's designs for a flying vessel from [George] Cumberland to Sir Jos [Joseph] Banks This covering letter from Cumberland to Banks introduces the five accompanying pencil drawings of dirigible balloons. Cumberland explains that he has slightly modified Henry Smeathman's balloon designs by removing the wings, although he has retained the vessel's folding membrane. Subject: Engineering Written at Church Court, Clements Lane, Lombard Street [London]. 4 March 1784