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).
Analysis of spark and arc characteristics under various ignition timing and spark gap conditions.
| Identifier | ExFiles\Box 63\4\ scan0007 | |
| Date | 26th May 1918 guessed | |
| (16) ZR6/600/5/R/A Same effect of retard as for 2mm. gap. (20) ZR6/600/5/R/B More arc than for advance. (21) ZR6/600/7/A/A Single spark. Striations are sometimes additional spark. Sometimes spark only. (22) ZR6/600/7/A/A Single spark. no arc. (23) ZR6/600/7/R/A Spark takes place more easily at retard. as recorded for 2 m/m.{Mr Moon / Mr Moore} Effect of retard on character of arc (24) ZR6/600/7/R/B Single spark. Some arc. | ||