This is the fifth occasion on which I have had the honour to address our Society and the third time I have chosen to discuss the same subject: “The stalling of aeroplanes.” I should apologise for thus harping upon a single string were it not that no subject could be more appropriate to an address in memory of Wilbur Wright, and were it not that until the stall is thoroughly understood and its attendant dangers pushed out of the way, aviation will not be free to play the great rôle which it is undoubtedly destined to play in the civilisation of the world.

The idea of navigating a certain type of sailing boat of mine by an autogyro instead of an ordinary sail has long been a desire of mine, in that I always have considered sailors to be very out of date as to rigs.

In conversation with J. Weir this question arose, whereupon he said that he had within his organisation of the Autogyro Company an engineer named O. Reder who had the same desire. We, therefore, got in touch and although the time was very short got out a rig and installed it upon a very small onedesign class, well-known in the Solent, namely, the Redwing. These boats are about one ton, and the rules governing their racing are that the hulls are standard and that any rig can be used, but that the sail area must not exceed 200 sq. ft.