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).
Results of further tests for leaky sparking plugs.
| Identifier | ExFiles\Box 33\3\ Scan089 | |
| Date | 22th November 1920 | |
| X1812-b Mr. Hives. 22.11.20 X.3641 X1812 SPARKING PLUGS. Further tests for leaky plugs:- 6 Titan plugs all O.K. 4 Cooke plugs " " 2 B.G. detachable" " GWH.{George W. Hancock - Head Chateauroux} | ||