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).
Inadequacy of Bentley headlamp illumination and potential improvements.
| Identifier | ExFiles\Box 61a\2\ scan0165 | |
| Date | 30th November 1933 | |
| Cx.{Major Len W. Cox - Advertising Manager} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By/CGH.{W Clough} Hs{Lord Ernest Hives - Chair}/Wst.9/MA.30.11.33. BENTLEY HEADLAMPS. Your memo reference Cx.{Major Len W. Cox - Advertising Manager}25/KW.28.11.33 has been passed on to me for reply. We agree with you that the Bentley headlamp illumination is inadequate and I am personally in touch with the lamp experts at Messrs.Lucas on the question. Our view is that changing from 48 watt to 60 watt bulbs will not help matters much as only a relatively small amount of extra brilliancy is obtained at the expense of 2 amperes extra load on the dynamo which with the present Bentley dynamo would cause overheating during long runs at high speed. We believe the lamps can be improved optically and by careful attention to the focussing when fitting the bulbs. Also the lamps require a micrometer focussing adjustment similar to the P.100. Another point is the careful inspection of lamp bulbs to ensure that the filament is central to the bulb cap. The so called "Blue Star" inspected lamp which Messrs.Lucas advertise so much we have found to be as bad as any other from this point of view. We will do all we can to let you have the results of our investigation as soon as possible. Hs{Lord Ernest Hives - Chair}/Wst. | ||