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 different magneto types with their advance, central, and retard values.
| Identifier | ExFiles\Box 35\1\ scan 187 | |
| Date | 16th November 1915 | |
| COPY. November 16th. 1915. To Mr Wormald. Mr Bailey. Order No. By4/H61115. MAGNETO COMPARISONS. TYPE. ADVANCE. CENTRAL. RETARD. 3 m/m 2 1/2 m/m 1/2 m/m Bosch. 55 55 55 B.T.H. 68 68 55 B.T.H. 110 100 55 Symme. 184 184 55 Dixie. 130 130 55. 1 m/m R.R.Cº DERBY (M) 14/12/15 100-1698 | ||