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 Jackall Jacks and their comparison to D.W.S. jacks.
| Identifier | ExFiles\Box 139\2\ scan0079 | |
| Date | 19th April 1934 | |
| X3117 S/W. c.c. to Hs.{Lord Ernest Hives - Chair} D.W.S.Jacks. Cx{Major Len W. Cox - Advertising Manager}8/KW19.4.34. Reference Hs{Lord Ernest Hives - Chair}/FD.{Frank Dodd - Bodies}2/KW18.4.34 , we are very interested to see that you are testing out a set of Jackall Jacks, and in due course shall hope to have some information from you as to the behaviour of these and how they compare with D.W.S. Cx.{Major Len W. Cox - Advertising Manager} | ||