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).
Graph of HP vs. Fan Speed for a standard 6-blade fan and a modified 3-blade fan.
| Identifier | ExFiles\Box 75\3\ scan0150 | |
| Date | 30th November 1934 | |
| C. HP - FAN SPEED CURVES OF VARIOUS FANS. 1. STD 40/50 6 BLADE FAN: 2. STD 40/50 FAN WITH 3 BLADES REMOVED. H.P. FAN SPEED. (R.P.M.) NEW 30-11-34 E.F.C / 24 | ||