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 closed and louvered bonnets during ascents on the Broccene Pass, Austria.
| Identifier | ExFiles\Box 78\3\ scan0031 | |
| Date | 17th September 1912 | |
| X496 3500 Tests with closed & Louvred Bonnets on Broccene Pass, taken By Sinclair with 1918 in Austria 17.9.12. Temperatures with both side windows open Ascents | Loss of Water | Atmos | Body | Foot Boards | | Bottom Somit | Bottom Somit | Bottom Somit 1st Ascent closed bonnet Shade off. | 1 3/4 Liters. | 9c. 7c | 25c 28c | 40c 62c. 2nd ascent Louvred bonnet Shade off. | 1 Liter | 11c 9c | 25c 30c | 40c 58c 3rd ascent Louvred Bonnet Shade on. | 2 1/2 Liters | 14c 11c | 23c 26c | 29c 45 4th ascent closed bonnet Shade on | 4 1/2 Liters | 16c 15c | 24c 27c | 31c 47c 5th ascent Without bonnet Shade on. | No Water Lost, Water Tempt. 90 | 14c. 11c | 24c 22c | 34c 34c | ||