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).
Letter from Zenith Carburetter Co. discussing the issue of bursting glass bowls and potential solutions.
| Identifier | ExFiles\Box 44\1\ Scan198 | |
| Date | 17th May 1928 | |
| .THE ZENITH CARBURETTER CO., Sheet No. 2. LIMITED. Messrs. Rolls-Royce Ltd. 17th May 1928 immediately in cold water without any sign of fracture or crack. It is also the most expensive type of glass. We have gone into the matter of the occassional bursting of the glass bowls with the "Pyrex" people, and also a number of other glass manufacturers and they tell us this is always liable to happen and is due to the fact that now and again a glass bowl will get through that has not been properly annealed. This means to say that there is an internal stress in the glass, and that being so it is always liable to burst As however they take the greatest care in annealing their glass it is only very occasionally that one gets through that is not quite up to the mark. We do not think that the fact of the letters being on the bottom of the glass is the cause of the trouble, and we are rather afraid that if we fitted a cork washer that after a short time the cork would spread out and become useless. We have adopted the fibre because this will maintain its shape and thickness even under pressure. It is not possible of course to get glass made to the same limits as metal, and there is bound to be a slight variation in thickness. Here again we think it is only very slight | ||