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).
Instruction sheet detailing a test on spark gap distances and the effects of induced sparks.
| Identifier | ExFiles\Box 52\1\ Scan044 | |
| Date | 28th September 1920 | |
| RR 250(150 BKS.)SHST.28-9-20.)MP 284389 ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. 4 Customer's No: SPARK GAP No. | MAXIMUM GAP ALLOWING REGULAR INDUCED SPARKS TO JUMP. 1 | .005" 2 | .004" 3 | .004" 4 | .004" 5 | .003" 6 | .004" No appreciable difference was observed in the intensity and regularity of the battery ignition sparks on 6.5mm gaps in air, when the magneto wires were earthed. In conclusion it will be seen that the greatest induced effect appears to be from the magneto wires to the battery ignition wires, the effect of earthing wires in the immediate neighbourhood of the live wires showing no appreciable detrimental effects. Signed H.E.W. This Sheet must be filed on completion of the work. | ||