Letter from J. H. Owen Harries, Shirely, Old Road, Frinton on Sea, Essex, to [Alan Archibald] Campbell Swinton FRS., 40 Chester Square, S. W. 1. Thanks Swinton for his reply and for returning his specification. Comments that, as Swinton inferred, the trial test must be of the physilogical effect which cannot be put on paper, with the mechanical side being quite straightforward. Comments that the question in analogous to that which would be presented by the invention of the bicycle in its modern form. Informs he has performed a series of experiments, inviting Swinton to see them. 2 November 1929