Discusses some calculations which he is doing for CD on the ratios of red and brown colouring in some animals.
14 Arlington St. | Piccadilly
My dear Father,
After grinding away for some time at the calculation of the red & white animals it suddenly occurred to me that I could find without any bother at all the ratio of the reds to the browns at any period, that is to say the percentage of the whole n
I also find that he knows Sullivan a little. Again I fd out today that Whiteford (a man at Tathum's) old Col. H Smith of Plymouth's grandson knows M
Balfour & Strutt I there & it is the last of Balfour that I shall see at Camb. as he has just been in for his degree & goes down next term. I went to Nilsson's concert last night & thought it extremely good.—
Your affectionate Son | G. H. Darwin
- f1 7158.f1The date is established by the reference to Arthur James Balfour's taking his degree (see n. 7, below) and by the reference to Christine Nilsson's evening concert (see n. 8, below). In 1869, 2 December was a Thursday.
- f2 7158.f2George was making calculation about a hypothetical population of red and brown animals. A statement of the problem that George was working on is in George's hand in DAR 85: B17:
Let there be a number of young animals all born brown & let them turn red (the operation being supposed instantaneous for each animal) at such a uniform rate that (if none died) half of the whole no: wd be red at the end of 8 quarter years; also let them perish irrespective of colour at such an uniformly diminishing rate that 2/3 the original no: are left after 4 quarter years & 1/2 orig: no: are left after 8 quarter years— It is then required to find the nos: of red & browns at any period.George's calculations are in DAR 85: B1b--17.
- f3 7158.f3George refers to Thomas Astley Horace Hamond. His uncle was Robert Nicholas Hamond.
- f4 7158.f4Robert Nicholas Hamond appears at Tun Street, Fakenham, Norfolk, in the Post Office directory of Cambridge, Norfolk, and Suffolk 1869.
- f5 7158.f5George refers to Bartholomew James Sulivan. See Correspondence vol. 18, letter from B. J. Sulivan, 27 June 1870.
- f6 7158.f6George refers to Ferdinand Mauger Whiteford, Charles Meaburn Tatham, Charles Hamilton Smith, and Emily Wedgwood, wife of Clement Francis Wedgwood.
- f7 7158.f7George refers to Arthur James Balfour and John William Strutt. The examination for the moral sciences tripos took place on 29 November 1869 (Cambridge University calendar 1869).
- f8 7158.f8Nilsson appeared in a series of evening concerts at Exeter Hall in London in 1869; the last two were on 1 and 15 December (The Times, 10 September 1870, p. 1).