The test results for two Wraith calorstats.
| Identifier | ExFiles\Box 131\3\ scan0040 | |
| Date | 28th February 1939 | |
| W/N. To GWH. {George W. Hancock - Head Chateauroux} from Rm {William Robotham - Chief Engineer} /EJH. 43 Rm {William Robotham - Chief Engineer} /FJH. {Fred J. Hardy - Chief Dev. Engineer} 3/MH. {M. Huckerby} 28.2.391 WRAITH CALORSTATS. The two Wraith calorstats we have sent you for trial on customers' cars were tested and both were found to commence opening at 80°C and to be full open at 90°C. Rm {William Robotham - Chief Engineer} /FJH. {Fred J. Hardy - Chief Dev. Engineer} | ||
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).