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).
Performance characteristic graph for a Watford 55% Armature, plotting degrees retard against RPM.
| Identifier | ExFiles\Box 65\3\ scan0053 | |
| Date | 29th December 1926 | |
| WATFORD. 55% Armature Length 2.046" DEGREES RETARD F.A. R.P.M. 5.5 mm 3 pt gap. 28+22 RELIEVED DIA 2.315 (S) Rad 16 7/8" (S) 2.305 12.30 FINAL RESULTS WILL COME WITHIN SHADED SECTION. Dec 29. '26. TT7.91 | ||