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).
Instrument dial illumination, bevel angles, and design specifications for Jaeger versus Smith dials.
| Identifier | ExFiles\Box 138\2\ scan0227 | |
| Date | 4th May 1933 | |
| - 2 - E.1/HP.4.5.33. ---------------- into a close fitting case, and the source of illumination is thereby restricted to localized areas. We think, however, the Bentley No.2. reaches a very satisfactory standard, and renders the dials sufficiently clear, at the same time being soft enough to drive in comfort with the illumination on. We have yet to find what is the best angle for the bevel on the glass, but so far as we have gone, an instrument with 16o bevel appears to be superior to one having 30o, the angle being measured relative to the axis of the needle shaft of the instrument. In view of the aforegoing results it was decided that no further slot instruments need be obtained for experiment. and the instructions regarding glass edge illumination should stand. A point raised by EV.{Ivan Evernden - coachwork} was that the dials should be of the Jaeger pattern and not those produced by Messrs. Smith, the former being finished with a different black to the latter, and the figures being a Venetian cream instead of blue white. BY/HD.{Mr Hayward/Mr Huddy} will see that the correct dials are specified. E.{Mr Elliott - Chief Engineer} | ||