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 board illumination, comparing silver versus white lettering for clarity and avoiding dazzle.
| Identifier | ExFiles\Box 105\2\ scan0051 | |
| Date | 17th February 1933 | |
| X5530 To Ex. from E.{Mr Elliott - Chief Engineer} E.1/HP.17.2.33. c.c. Sg.{Arthur F. Sidgreaves - MD} Lor. IN. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} re Instrument Board Illumination. Replying to your memo Cx{Major Len W. Cox - Advertising Manager}11/KW.16.2.33, we do not seek to increase the amount of light on the instruments but to reduce it and render it so uniform and soft that the illumination can be left on all the time if required without giving offence to the drivers vision. I have such an example on my own car which it is agreed fulfils this condition and at the same time the instruments are well illuminated and easy to read. With regard to the colour of the lettering, my point is that given uniform illumination silver lettering requires a more intense degree of illumination and increases dazzle and then is not so good as there is insufficient contrast to render the figuring clear. In the special A.T. panel containing speedometer tachometer and clock supplied for the Bensport the makers have achieved an excellent degree of soft and uniform illumination, using only ports in the side of the instruments, and the result obtained is very largely due to the degree of contrast and clear cut effect obtained with etched white lettering on a warm black ground. BY.{R.W. Bailey - Chief Engineer} agrees that these dials are a first class job and quite up to the standard of finish we require for RR. productions. We propose to obtain some dials of exactly the same finish to try against the silver lettering, both for appearance in daylight and illumination at night. .E. | ||