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).
The design considerations for implementing concave lighting on Bentley instruments.
| Identifier | ExFiles\Box 168a\1\ img004 | |
| Date | 4th April 1935 | |
| W/S. To Cx.{Major Len W. Cox - Advertising Manager} from E.{Mr Elliott - Chief Engineer} c. By/Cgh{W Clough} Hs{Lord Ernest Hives - Chair}/Wst. By/RD. Concave lighting for instruments. Referring to your memo Cx.{Major Len W. Cox - Advertising Manager}6/KW.2.4.35, this is a question of altering design. The concave lighting would be easy to apply to the small instruments on the Bentley but in the case of the speedometer and tachometer more room would be required for housing the extra pea lamps necessary and the patch would assume a rectangular form which would be rather difficult to fit in in the space available. As matters stand at the moment, Sg.{Arthur F. Sidgreaves - MD} has said that the Bentley should not be altered for the time being, and we think this is certainly wise until we have more experience with the concave lighting. We anticipate that experiments will be made in due course for changing from glass edge illumination to port lighting with concave dials on the two large Bentley instruments. E.{Mr Elliott - Chief Engineer} | ||