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).
Blueprint graph showing heating and cooling curves for a KLG 850 A spark plug after a 650-mile run.
| Identifier | ExFiles\Box 162\4\ img172 | |
| Date | 29th August 1936 | |
| (3) KLG 850 A, HEATING ———, COOLING --- ---, PLUG RUN FOR 650 MILES, IN B.23:AE, TEMPRE °C, 29.8.36 | ||