In order to prove the design, Griffith and several other engineers at the Royal Aircraft Establishment built a testbed example of the compressor in 1928 known as "Anne", and planned to follow this up with a complete engine known as "Betty".
In order to prove the design, Griffith and several other engineers at the Royal Aircraft Establishment built a testbed example of the compressor in 1928 known as "Anne", the machinery being built for them by Fraser and Chalmers. After Anne's successful testing they planned to follow this up with a complete engine known as "Betty".