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).
Testing of a Duff-Jack by the Experimental Department.
| Identifier | ExFiles\Box 26\3\ Scan022 | |
| Date | 10th May 1920 | |
| ToHS from DA.{Bernard Day - Chassis Design} X4057 DA{Bernard Day - Chassis Design}4/CB10-5-20. RE JACKS. We are sending you separately, a Duff-Jack from the Duff Jack Sales Co., which we have recently arranged with Mr Johnson shall be tested thoroughly in the Experimental Department, to see if there is anything in it. Hancock DA.{Bernard Day - Chassis Design} [Illegible signature] [Illegible circular stamp] attended to FHS 21/7/20 | ||