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).
Procedure for establishing the true straight-travel axis of a car using a transit and a flat plate setup.
| Identifier | ExFiles\Box 170\3\ img078 | |
| Date | 21th May 1936 guessed | |
| 3 on the radiator shell showing this line, which is the true straight-travel axis of the car. By turning the transit through 90° we have a line truly square with the travel-axis. (Getting the true straight travel axis is difficult since wind affects it a lot. A mechanical set-up of the car on a flat plate has been used to get this line. We do not have the 'perfect' solution.) A post is mounted at the center of the track and a ring is marked round it at any convenient height. INDICATOR TRANSIT d KNOWN l KNOWN R (KNOWN) | ||