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 showing maximum gap vs. speed curves for coil models E12 and E16.
| Identifier | WestWitteringFiles\D\May1920\ Scan73 | |
| Date | 17th May 1920 | |
| MAXIMUM GAP-SPEED CURVES FOR COIL No. E12 (o) AND COIL No. E16 (x) MAXIMUM GAP (INCHES) .500 .400 .300 .200 .100 E16 E12 R.P.M. OF CONTACT BREAKER. 0 200 400 600 800 1000 1200 1400 1600 1800 R.C.S.J. 15/5/20 E.F.C. 17/5/20 | ||