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).
Requesting the manufacture of a central electrode to go with an earthed electrode for an annular spark gap.
| Identifier | ExFiles\Box 54\3\ Scan244 | |
| Date | 9th October 1924 | |
| X4645 To RHC.{R. H. Coverley - Production Engineer} from EFC. EFC2/T9.10.24. X.4645. RE ANNULAR GAP. Will you kindly now have made for us one further central electrode .125" dia. This will go with the earthed electrode of inside dia. .312", which you have already made for us. We hand you the annular spark gap herewith. EFC. | ||