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).
Diagrams illustrating the operation of a petrol tank's air vent and balance pipe system.
| Identifier | ExFiles\Box 44\4\ Scan036 | |
| Date | 9th April 1929 guessed | |
| P. dry. B. petrol and fluid. Air vent covered with petrol - air escapes out of balance line and petrol enters. Liquid rises and compresses air in balance pipe due to movement of car. | ||