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).
Test report page with numbered items for remarks, voltage, and gap measurements.
| Identifier | ExFiles\Box 69\1\ scan0287 | |
| Date | 2nd January 1930 guessed | |
| -4- (9) Remarks :- At 10 volts :- At 8 volts :- (10) Maximum gap and corresponding voltage. (11) Remarks:- (12) Remarks :- | ||