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 numerical data for 'RRA' and 'EXP. NEEDLE'.
| Identifier | ExFiles\Box 31\5\ Scan078 | |
| Date | 20th July 1933 guessed | |
| RRA. 89 86 81.6 77.5 74 70.8 68.3 65.5 62.5 60 57.5 54.7 52 EXP. NEEDLE. 89 84.3 80.7 78 76 73.7 71.5 69.5 67.5 65.5 63.5 61.6 60 -------- | ||