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).
The melting status of Dynamo Sentinels on various models.
| Identifier | ExFiles\Box 51\1\ Scan241 | |
| Date | 22th September 1923 | |
| X. 4383 EFC {E. Fowler Clarke - Electrical Engineer} 4/T22.9.23. X.4383 - DYNAMO SENTINELS. 82° sentinels have not been melted on 3-GII, Two have been melted on 4GII, three on 6GII and one on 7GII. E.F.C EFC. {E. Fowler Clarke - Electrical Engineer} | ||