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).
Design of a Cambridge thermometer dial and the potentially misleading use of a red sector to indicate high temperatures.
| Identifier | ExFiles\Box 175\4\ img014 | |
| Date | 16th March 1925 | |
| X38757 Hs.{Lord Ernest Hives - Chair} BY18/H.{Arthur M. Hanbury - Head Complaints} 16. 3. 25. We are handing you herewith the Cambridge Thermometer which has been made to instructions received from Sales. It has a section of the dial marked red, which to my mind is misleading, as we certainly do not consider it dangerous to be above a certain figure. Sales also asked for a finger painted white of different dimensions. They have fitted a different type of finger, and sent with the thermometer a standard finger. I would like you to look at these parts, and when you have made up your mind what you want to say about it, write to Sales and tell them what you think about the job. In view of our boiling troubles, it seems to me that the proposal to have a red sector will be far worse than a red rag to a bull so far as the customer is concerned. We are bad enough when we only has a necessary 100ºC. marked on it, but if we gave him the impression that he is in danger, when he gets above the first red sector, I do not think any of us will survive. [Handwritten] Without the red sector the gauge would appear satisfactory & an improvement on present ones. BY.{R.W. Bailey - Chief Engineer} | ||