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).
Note comparing the Ediswan spiral filament to the Osram wavy type filament.
| Identifier | ExFiles\Box 61a\1\ scan0022 | |
| Date | 1st December 1914 guessed | |
| R.R. Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer}6/L231114. Sheet 2. Osram, alsb that the Ediswan form of filament (spiral) is better than the Osram wavy type. [Watermark text] MADE IN CHORLEY 1809 DICKINSON BOND | ||