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).
Confirming the price being paid for Exide type S.1 hydrometers.
| Identifier | ExFiles\Box 44\5\ Scan098 | |
| Date | 30th January 1928 | |
| X3741 30.1.28. We have to-day received information from the O.O. that we are paying 3/6d. each for Exide type S.1. hydrometers. EFC. | ||