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).
Test readings for an A.T. Speedometer at various temperatures and speeds.
| Identifier | ExFiles\Box 50\4\ Scan229 | |
| Date | 23th November 1928 | |
| Y4308 23.11.28. A.T. SPEEDOMETER. Instrument No. A.677 N800. 14/52 gave a reading of 48.0 m.p.h. at 600 r.p.m. at 15°C, and 47.0 m.p.h. at 19°C. 800 r.p.mile would be 45.0 m.p.h. EFC. {E. Fowler Clarke - Electrical Engineer} | ||