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).
Comparison of the quality and cost of Firth springs versus Lemoine and American springs.
| Identifier | ExFiles\Box 106\1\ scan0135 | |
| Date | 16th August 1928 guessed | |
| contd :- -2- spring or American spring is due to [strikethrough]better[/strikethrough] the superior finish of the surface, or the workmanship, we ought to insist that Firth springs are at least equal, especially as I understand the cost to us of the Firth springs is greater than the Lemoine springs. R.{Sir Henry Royce} | ||