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).
Hand-drawn schematic of a speedometer drive assembly.
| Identifier | Morton\M11\ img176 | |
| Date | 25th October 1918 | |
| VEE PULLEY SAME SIZE AS DRIVING SWIVEL PIN FLEXIBLE DRIVE 4 TO 1 SPUR GEAR RR SPEEDOMETER DRIVE H P Ld G 612 F4200 (L) 'A' 1M' 25-10-18/O 2517 | ||