Claimed as Proof Against Spinning: Our German Correspondent Describes a Machine which is Claimed to be Proof Against Auto‐rotation

COUNTLESS practical and theoretical proposals have been made for the prevention of auto‐rotation. Exact science has long been well acquainted with the actual aerodynamical process. In Germany, Prof. Fuchs of Berlin and Prof. Hopf of Aix‐la‐Chapelle may be named as leading experts engaged in the investigation of auto‐rotation. The Deutsche Versuchsanstalt für Luftfahrt has also provided very valuable contributions to the study of the problem. Among English workers may be named Bairstow, Bryant, Gates and Hall, while it is an Englishman, Handley‐Page, with his famous slotted wing, who has made the most practical progress. This invention at least enables the machine to maintain lateral stability when it gets too steeply banked, that is it prevents one wing from dropping. Nevertheless, neither the Handley‐Page slotted wing nor any other device can quite preclude the danger of auto‐rotation. Intentional or unintentional error in manipulation still tend to produce auto‐rotation.