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).
Material composition of 'Sparkite' contact points, comparing silver, tungsten, and platinum.
| Identifier | ExFiles\Box 35\5\ scan 101 | |
| Date | 26th April 1920 | |
| X.2894. RR/G26.4.20. To EFC. from R.{Sir Henry Royce} Copy to CJ. " " En. ------------------------------------------------------ X.3768. RE "SPARKITE" CONTACT POINTS. X.800. X.1818. X.1819. X.2894. ------------------------------------------------------ I am pleased to hear you have found "Sparkite" Contact Points are merely silver points, and therefore they are not good enough for the battery work goes without saying, because we want the best. I shall be glad if you will re-test the idea of using the tungsten points instead of platinum, which appear to be quite right in some of the applications we have seen. There is still also the matter of using tungsten for the distributor instead of platinum, or we might try even for this purpose, silver instead of platinum. It is just possible that the silver will be quite good enough for this purpose, and be more easily worked than the tungsten. R.{Sir Henry Royce} | ||