From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Hand-drawn diagram with dimensions for an air silencer for a twin-choke Zenith carburetter.
| Identifier | ExFiles\Box 122\1\ scan0120 | |
| Date | 25th June 1931 guessed | |
| AIR SILENCER FOR TWIN-CHOKE ZENITH CARBURETTER EACH TUBE TO HAVE 4 LESS To FOLLOWING DIMENSION OF "A" OUTER TUBE "A" = .450 INTERMEDIATE TUBE "A" = .600 INNER TUBE "A" = 1.000 .500 | ||