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).
Instructions and observations from a test on battery ignition polarity and spark gaps.
| Identifier | ExFiles\Box 52\1\ Scan052 | |
| Date | 28th June 1920 | |
| RR 239 (100 BKS.) (6H57.28-6-20.) MP 224399 ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. 3. Customer's No. (2). The last test was carried out with Battery ignition polarity normal, and so secondly the effect was observed with the polarity of the coil reversed. The max gap now necessary to avoid induced sparks jumping (Battery ignition wires sparking - only) was observed to be .184". On switching both ignitions on together (B.I polarity still reversed) sparks were observed to jump approx every min, the initial spark over being followed by 5 or 6 others in rapid succession and the maximum gap necessary to avoid during a period of 5 mins a spark over being .198". Signed contd. This Sheet must be filed on completion of the work. | ||