The Marrett apparatus: is hospital anaesthetic equipment compatible with field use?

Major Rex Marrett in 1945 was commissioned to design an anaesthetic apparatus for field use to replace the Field Pattern Boyle's apparatus in use during the Second World War. His design was both elegant and avant garde and was capable of being used with all agents and circuitry then in current use. It was an economical machine with vaporizer in circle and carbon dioxide absorption as its chief mode of operation. The equipment and its later developments are described. Eventually the desire for knowing volatile agent concentrations led to its decline with production ceasing in 1976.