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).
The 'Stop-It' anti-freeze compound, with an extract from the manufacturer detailing its glycerine-based properties and performance.
| Identifier | ExFiles\Box 151\3\ scan0111 | |
| Date | 26th November 1929 | |
| Hs.{Lord Ernest Hives - Chair} x4516. ROY{Sir Henry Royce}/GEA1/EB.26.11.29. Anti-Freezing Compound. We wrote to the Imperial Chemical Industries Ltd, and the County Chemical Co.Ltd, with regard to the above matter, and the former write saying, the matter has been put before the Technical Department of Messrs. British Dyestuffs Corporation, and they will communicate with us as soon as they get their reply. We have requested the County Chemical Co.to send us a sample of their "Stop-It" Freezing Compound, and we will pass it on to you as soon as we receive same. Meantime, we attach hereto, extract from letter received from said firm. "This product, which contains a proportion of "Glycerine, is put up in quart tins which retail "at 7/6d. each, and this size is suitable for "radiators having a capacity of between 2 and 3 "gallons." "It has been thoroughly tested out under practical "conditions during the severe frost which was "experienced last February, and it was found to "keep water in a liquid state at as low as 35 "degrees of frost. Below that temperature a "certain amount of soft ice was formed, but this "would not have a detrimental effect on the cooling "system, and it is safe to say that "Stop-It" "Freezing will prevent water forming a solid mass "of ice at almost any temperature, and certainly "below a temperature likely to be experienced in "this country." "Stop-It" Freezing was also found to prevent "corrosion, and it also has a preserving effect "on rubber connections, leather washers, etc." ROY{Sir Henry Royce} [Signature] | ||