Comparison sketch of Firestone and Goodyear wheel rim sections with handwritten notes.
| Identifier | ExFiles\Box 42\4\ Scan145 | |
| Date | 9th June 1920 | |
| Fig I This should be 1/8" radius 1/16" A Good design well rounded corner. Firestone section of rim This should be 1/8" radius. 1/16" Fig II R + This very sharp corner gave trouble in another similar make of rim Goodyear section of rim Copy of sketch attached to Mr. Fergusson's letter of June 9 '20 | ||
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).