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).
The observed effect of earthing one set of ignition wires.
| Identifier | ExFiles\Box 52\1\ Scan042 | |
| Date | 27th August 1929 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. (2) Customer's No. the effect of earthing one set of wires was observed in each case. With the battery ignition switched off and the magneto sparking, small induced sparks could be obtained from the ends of the battery ignition wires connected to the spark gaps, of magnitude as shown in the table below. From this table it will be seen that the largest gap obtained corresponds to the longest length of wire in the tube (i.e. No 6 threads the whole length of the tube), the other spark lengths varying consistently as the length of wire in the tube. Signed contd This Sheet must be filed on completion of the work. | ||