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).
Graph of Spark Length vs. Cable Length curves for a standard R.R. and a Remy 6 Volt ignition coil.
| Identifier | ExFiles\Box 52\3\ Scan356 | |
| Date | 20th August 1920 guessed | |
| SPARK LENGTH — CABLE LENGTH CURVES for ① STANDARD R.R. IGNITION COIL. (x). ② REMY 6 VOLT " " (•). Y-AXIS: GAP. (INCHES) .4 .3 .2 .1 X-AXIS: LENGTH of CABLE. (FEET) 2 4 6 8 10 12 14 16 18 20 | ||