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).
Graph comparing friction in different types of cantilever springs under varying loads.
| Identifier | WestWitteringFiles\E\November1920\ Scan39 | |
| Date | 5th November 1920 | |
| FRICTION IN CANTILEVER SPRINGS ① THICK LEAF TYPE 6 LEAVES GREASED ② " " " " RUSTY ③ THIN LEAF TYPE II LEAVES GREASED ④ " " " " RUSTY BOTH TYPES OF SPRING ARE THE SAME STRENGTH FRICTION IN LBS 250, 225, 200, 175, 150, 125, 100, 75, 50, 25 LOAD IN LBS MEASURED AT END OF SPRING 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000 5/11/20 E&A | ||