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).
Cooling effectiveness of different bonnet designs, with a direct quote from Mr. Royce.
| Identifier | ExFiles\Box 119\3\ scan0043 | |
| Date | 3rd July 1914 guessed | |
| -2- was not quite so good as the louvred for keeping the water cool; approximately the average benefit from the shutters being open is 4% whereas the difference between the temperature when plain and louvred bonnets are used is 8%. The above test however was made with Bonnets containing single shutters, whereas we are now trying bonnets with a shutter at each end, this is now being tested on cars on the Continent. Mr Royce has recently stated :- "I am very anxious to do away with "the louvred bonnet. I consider we "are spoiling the car more by being too "cool in winter even in this district". We return all the correspondence dealing with this matter. p. Wor.{Arthur Wormald - General Works Manager} | ||