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).
List of recommended changes for insulation materials in various electrical unit components.
| Identifier | ExFiles\Box 24\2\ Scan167 | |
| Date | 31th August 1921 guessed | |
| -3- RECOMMENDED CHANGES OF INSULATION IN ELECTRICAL UNITS. BALLAST. Piece No. | Name. | Present matl. | Proposed Material. F.7343-4 | Washers | Mica | Bakelite dilecto, gd.A. F.7354. | Bush | Micanite. | " " " F.7345 | Washer | Mica | " " " F.7893 | " | Micanite | " " " ACTUATOR. F.7051-2 | Plates. | Ebonite. | {Bakelite micarta (paper) or Bakelite dilecto XX. F.7056. | Washers. | Presspahn. | { F.6710. | " | " | " " F.7269. | Plate. | Ebonite. | " G.4288. | Washers. | Presspahn. | " G.4287 | Tube. | Paper | " MAIN SWITCH. E.12965. | Plate. | Vulcasbestos. | Continental Bakelite or B-micarta (duck base) E.12955 | Washer. | Micanite. | Bakelite-dilecto XX or Bakelite-micarta (paper). E.12953. | " | " | " E.12948. | " | Vulcasbestos. | " E.12956. | Tube. | Ebonite. | " " E.12957. | " | " | " " E.12961. | Cone washer. | Presspahn. | " " E.12970 | Cone tube. | Manilla paper. | " " F.6710. | Cone washer. | Presspahn. | " " F.6711. | " | " | " " PUSH BUTTON G.5534. | Plug. | Red Fibre. | Bakelite-linen-rod. | ||