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).
Test results for eleven samples of production Maconit H.T. cable after water immersion.
| Identifier | ExFiles\Box 168\1\ img084 | |
| Date | 21th January 1930 | |
| X 3860 21.1.30 X.3860 MACONITE H.T. CABLE. Eleven samples of production Maconit H.T. cable selected from eleven coils, successfully withstood 19,400 volts R.M.S. for 15 mins. after 24. hrs. immersion in water. EFC/HEW. | ||