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).
Blueprint for a magnet core with specified dimensions, material, and polarity.
| Identifier | ExFiles\Box 165\3\ img109 | |
| Date | 26th March 1935 guessed | |
| .750 DIA +10 -10 2.925 DIA -2 2.140 DIA +2 MAGNET CORE - SCALE 2/1 MATERIAL - NIFAL ONE OFF WITH N POLARITY ON CONCAVE SURFACE ONE OFF WITH S POLARITY ON CONCAVE SURFACE 2 HOLES .161 DIA +25 | ||