 H5 is owned by the Worshipful Company of Clockmakers of London, and was previously on display at the Clockmakers' Museum in the Guildhall, London, as part of the Company's collection; since 2015 the collection has been displayed in the Science Museum, London.In the final years of his life, John Harrison wrote about his research into musical tuning and manufacturing methods for bells.His tuning system, (a meantone system derived from pi), is described in his pamphlet "A Description Concerning Such Mechanism ... (CSM)".