This article examines the development and use of rotation therapy in the emerging field of psychiatry at the beginning of the 19th century, and the cross-fertilization between British, Irish, German, French and other European proponents of 'Cox's Swing'. Its short-lived popularity is linked to prevalent Enlightenment thought, to the development of an industrial and technological society, to the modern medical theories of irritability, and to the new practice of 'moral management' of the mentally ill. Case studies documenting the use of the Swing are considered from these perspectives, and are compared with contemporary public reactions in the form of publications in newspapers and of a literary text by German Romantic author Ludwig Achim von Arnim.