Shaw, Köhler and the Disc Valve in Britain

The search for improvements in brasswind instruments with valves in the first half of the nineteenth century led in England to the development of the disc valve, a type in which additional tubing is introduced by rotation of discs. The disc valve, developed by John Shaw of Glossop in Derbyshire in collaboration with the Köhler firm in London, had its precursor in the swivel valve, patented in 1838. Biographical information about Shaw shines light on his possible involvement in the manufacture of the only surviving swivel-valve trumpet at The Metropolitan Museum of Art in New York. The transition from the swivel to the disc valve can be traced in another trumpet in New York and reports in the Practical Mechanic & Engineer's Magazine. The technological development of Köhler disc-valve instruments is put in chronological order, based on an examination of surviving instruments and 1851 Great Exhibition catalogues. Using contemporary and modern reports as well as acoustical analysis, an assessment of the quality of the disc valve is given. A list of all known Köhler disc-valve instruments is appended.