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).
Secret memo outlining the required properties for a reliable friction material for a servo system.
| Identifier | ExFiles\Box 73\1\ scan0121 | |
| Date | 4th March 1924 | |
| X.9910 S E C R E T. To Hs.{Lord Ernest Hives - Chair} DA.{Bernard Day - Chassis Design} from R.{Sir Henry Royce} c. to CJ. RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} RE. FRICTION MATERIALS FOR SERVO. X.9910. This requires a material whose chief advantage is consistency under all conditions, which means wearing well, the same worn and new, not damaged by temperature, damp or dry, and preferably not affected in life and efficiency by oil. I do not think it matters if the co-efficient is high or low within reason, so much as that it shall be thoroughly reliable. R.{Sir Henry Royce} | ||