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).
Rating test graph showing load versus deflection for a Spectre engine suspension rubber mount.
| Identifier | ExFiles\Box 93\1\ scan0187 | |
| Date | 3rd September 1935 | |
| 3-9-35 SPECTRECodename for Phantom III ENGINE SUSPENSION RUBBER RATING TEST F87575 LEC 4462 DEFLECTION - INS .070 .060 .050 .040 .030 .020 .010 LOAD - LBS 50 100 150 200 250 300 ℓ | ||