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Cirrus-Hermes Engineering Company, of Purley Way, Waddon, Croydon
1931 Acquired Cirrus Aero Engines Company.
After purchase, the Cirrus Hermes I, II, III & IV were produced ranging in power from 105 hp to 140 hp depending on type. The later Cirrus engines were designed to run inverted.
1933 Constructors of low-powered four in line air cooled aero engines. Works: London Air Port, Croydon, Surrey. Registered Office: 274 Gresham House, Old Broad Street, London, E.C.2.
1933 Patent - Improvements relating to inertia starters for internal combustion engines.
1936 On the formation of Blackburn Aircraft Ltd, Cirrus-Hermes Engineering was an associated company but was not brought into the Blackburn group because its new products (engines) were still in the development phase
1937 Advert for Aero Engines. 90 h.p. "Cirrus Minor" Aero Engine. 150 h.p. "Cirrus major" Aero Engine. Both of the above are 4-cylinder-in-line inverted air-cooled engines. (Engineering/Metals/Quarry, Roads and Mining/Transport - Stand No D.921) 
1937 Aero engine manufacturers. "Cirrus" and "Cirrus Hermes" Aero Engines.