Test procedure involving Sodium Chloride and a discussion on water hardness treatment.
| Identifier | ExFiles\Box 149a\3\ scan0029 | |
| Date | 24th August 1920 | |
| R.H. mssm 50 T) (S.G. 755, 24-8-20) G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 2650 H11/EB29720. Contd. -2- Sodium Chloride maintaining the solutions and tubes at about 90° C for eight hours, cooling during sixteen hours, then another eight hours at 90° C and so on. We will report the action after two or three days but will keep the tests on for a considerable time. Free carbon dioxide (or carbonic acid) is always present in "temporary" hard water; it is removed by the addition of Lime (an alkaline substance) & "permanent" due of chlorides & sulphate of lime & magnesia are also eliminated by an alkaline substance i.e. Sodium carbonate so that - it is difficult to consider it alkaline before treatment. HCHb | ||
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).