From Horace Darwin 17 August 1874
1 Pier Road | Erith
Aug 17th. 74
Dear Mother
Will you tell Father that I have hunted in the only two book’s about the steam engine wh. I know of and can find nothing of any good. I had a talk with the Manager Mr Moberly, & he said that feed water heaters did not get so much choked up as the boiler, but I do’nt think this shews so very much, because the only kind of deposit wh. is much harm, I believe, is a solid insoluable crust wh. coveres the inside of the boiler; and the feed water heater may precipitate the carbonate of lime, as powder and not as “scale” as it is called; and if it does the precipitate would go into the boiler and might get turnde into the scale there.1 What makes me think that this is possible is that there is a patent for preventing the scale by sending an electrical current from the water to the metal of the boiler, but whether this acts I do’nt know, we are trying it at the works but the boiler has not been cleaned out since it was put up, so they dont know how it works; if it does answer it shows that there is something very odd about it, so one can’t tell for certain. Mr. Moberly also said that he thought that 100o Far.2 would precipitate very little of the Car. of lime; I will get another talk with him. All he said only applied to fresh warter heaters. I looked at Watts Dictionary of Chemistry & found a good deal about it under. Water-Solution— gaves absorption of—Carbonate of Calcium—Carbonic anhydride— water does disolve less Carbonic acid the hotter it gets.3
I want to hear very much what answer Murray gives.4
Yours affec son | H Darwin
Footnotes
Bibliography
ODNB: Oxford dictionary of national biography: from the earliest times to the year 2000. (Revised edition.) Edited by H. C. G. Matthew and Brian Harrison. 60 vols. and index. Oxford: Oxford University Press. 2004.
Watts, Henry. 1872–4. A dictionary of chemistry and the allied branches of other sciences. 2d edition. 5 vols. London: Longman, Green, & Co.
Summary
The occurrence and prevention of scale in boilers.
Anxious to hear Murray’s reply [to CD’s letter 9598].
Letter details
- Letter no.
- DCP-LETT-9603
- From
- Horace Darwin
- To
- Emma Wedgwood/Emma Darwin
- Sent from
- Erith
- Source of text
- DAR 162: 70
- Physical description
- ALS 5pp
Please cite as
Darwin Correspondence Project, “Letter no. 9603,” accessed on 6 October 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-9603.xml
Also published in The Correspondence of Charles Darwin, vol. 22