Letter from [Alan Archibald Campbell] Swinton, to Colonel. Sir Henry [George Lyons] FRS Unsure whether there is anything new in principle in Baird's television apparatus over what had been published by Nipkow in his patent of 1884, enclosing a copy of his letter to Nature in which he deals with the subject, corroborated by A. Dauvillier [enclosures not present]. 1 July 1929