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 that payment is required for filters as no agreement for free supply was found.
| Identifier | ExFiles\Box 44\1\ Scan209 | |
| Date | 6th June 1928 | |
| To G/WFH. from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}3/LG12. 6.28. X3700 With reference to G/WFH/CA.13/HOLL.6.28. We have had these filters. We can find no agreement as to there being supplied free of charge. We therefore suppose we shall have to pay. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||