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).
And comparing the dimensions of various headlamps from C.A.V. and Lucas.
| Identifier | ExFiles\Box 61a\1\ scan0025 | |
| Date | 3rd December 1914 | |
| X.1357 for/Hy{Tom Haldenby - Plant Engineer}5/L31214 RE HEAD LAMPS. J.{Mr Johnson W.M.} for R.{Sir Henry Royce} 3-12-14. X.1357 Your memo R11/IB11214. With reference to the power of various sizes of lanterns, we have just received from the C.A.V. people a pair of specially made Head Lamps having a reflector the same diameter as the large "F" type but the lamp is 1 3/8" less in outside diameter. This lamp should give us a powerful light without being unduly big. The dimensions of the fronts are as follows. | | C.A.V. large F.{Mr Friese} | C.A.V. small F.{Mr Friese} | C.A.V. Special | Lucas C76 | |---|---|---|---|---| | Diameter of front glass. | 10" | 9" | 10" | 8 1/2" | | Outside dia. of lamp | 12 1/4" | 10 3/4" | 11 3/8" | 11 1/4" | I believe that the Lucas lanterns fitted to 58NA{Mr Nadin} are a larger size than C76 quoted above. My objection to the Lucas lamp is that the outside diameter is unnecessarily large compared with the size of the reflector, in fact most head lamps have this objectionable feature. The special C.A.V. has this reduced to a minimum as will be | ||