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).
Page two of a letter discussing trouble with material expansion between aluminium and steel, and a new satisfactory design.
| Identifier | ExFiles\Box 79\1\ scan0203 | |
| Date | 21th October 1919 guessed | |
| - 2 - quite satisfactory, but curiously enough in this pattern gave trouble through the difference in expansion between aluminium and steel. We have now remedied this, and the plugs we are now making I consider to be a really satisfactory design. Yours faithfully, Signed. AML. | ||