# From G. H. Darwin   19 November 1880

Trin. Coll. Camb

Nov. 19. 80

My dear Father,

I received the book this morning & have just turned over the pages & looked at the wood-cuts.1 I am rather disappointed to see how carelessly they are printed; they are not comparable to the proofs I saw at home. I notice a slight mis-statement Fig 149 was not from a photo. And surely 147 was not either2 Fig 162 there was a photog. but so blurred that I drew the left hand one almost entirely from the plant as I believe. The right hand one was drawn entirely from nature.3 If I am not right in my memory of this I shall be enormously surprized & especially I remember the right hand fig. of 149 because it was the hardest one which was done entirely from nature. However this is all very unimportant.

I have been going on with ripple-marks & can now produce them in a flat bath with almost the regularity of a mathematical figure with wave lengths varying from perhaps 3 or 4 inches to $\frac{1}{2}$ inch.4 I can produce no ripple mark with currents & I believe that when ripple is produced along with current the current must be slow & wave motion must be going on on the surface   I find a rough formula for wave length of ripple-mark as a multiple of the greatest velocity of the water relatively to the sand in the oscillatory motion. Also no ripple is produced if this max: vel: is less than $\frac{1}{2}$ a ft per sec. & again none if greater that 1.2 ft per sec. There is a marked tendency to sort the sand along the crests of the ripples.

I am inclined at present to think it is a complex affair partly depending on the rates at which different sized grains acquire the velocity of the water moving past them & partly on my previous theory of the sand being elongated   I fancy I shall be able to reduce my apparatus so as to make absolutely regular ripples. They already are good. I got the other day 66 ripples round the bath with only one partially broken. The more I see the more I think Lyell utterly wrong.5

I am in despair about my astronomy. I am in this position that I must refer to my theory in its bearing on the solar system as a whole that I can not make any problem which shall reasonably represent the case & that I must write a sort of general discussion which will I fear be very unsatisfactory & will be more speculative than I like, and moreover I fear the outcome of the whole to any one who does not read thoro’ly will be more unfavourable to the theory than I am convinced it shd. be.6

I have been rather better for about a week now & have worked spasmodically. My cold, quà cold, has much subsided, tho’ it is at me pretty vigorously in the usual way.

Arthur Balfour has been here for a few days, but he had’nt got very much politics to tell.7 I dined last night at Horaces & met Miss Gladstone & afterwards we went to the Amateur Dramatic play.8 We went down in the tram-car in an awful crowd with Ida sitting on Miss G’s lap, & then walked on thro’ the rain   We had a fearful storm of wind & rain last night, all night thro’. & only stayed at the play for two or three acts. It was’nt at all good & I had seen it before—.

A.B. wants Horace to do another little job at Whittinghame but I don’t think it will be much—9 It is something wh H. had suggested before.

I am dining at F. Balfour’s tonight to meet Evans (J. E’s son) who is come back from Bosnia & Ragusa for a short visit in England. I think you read his book.10

Your affec. son | G H Darwin

## Footnotes

George had done several drawings for Movement in plants, which was published on 7 November 1880 (Freeman 1977). CD acknowledged George’s work in Movement in plants, p. 8.
See Movement in plants, pp. 356, 358. Both captions read, ‘Copied from a photograph; figures reduced.’
See Movement in plants, p. 385; the figure shows Nicotiana glauca with leaves expanded during the day and asleep at night. The caption indicates both figures were copied from photographs and reduced. See plate on p. 401 and frontispiece.
George had a special trough made to experiment on producing ripple-marks in sand covered by water (see letter from G. H. Darwin, 9 October 1880). George’s experiments are described in his paper ‘On the formation of ripple-mark in sand’ (G. H. Darwin 1883). His work demonstrated that the formation of irregular ripple marks was due to vortices carrying sand up the lee slope while the direct current moved sand up the weather slope.
Charles Lyell had discussed the production of ripple-marks in A manual of elementary geology (C. Lyell 1851, pp. 19–21). He accounted for ripple-marks in sand (under air) as a result of the direct action of the wind on the weather slope alone (see ibid., p. 20 fig. 9).
George had written a series of papers on tidal friction and related subjects (see, for example, G. H. Darwin 1878a, 1878b, 1879a, and 1880). This work related to the underlying problem of cosmic development; George presented a paper titled ‘On the tidal friction of a planet attended by several satellites, and on the evolution of the solar system’ (G. H. Darwin 1881) in January 1881. He later presented a non-technical account of tides and their connection with astronomy in The tides and kindred phenomena in the solar system (G. H. Darwin 1898).
Arthur James Balfour was an MP; he had been a student at Trinity College, Cambridge, at the same time as George.
Horace and Ida Darwin also lived in Cambridge. Helen Gladstone was the youngest daughter of William Ewart Gladstone; she was secretary to the vice-principal at Newnham College, Cambridge, at this time.
Whittingehame House in East Lothian, Scotland, was Balfour’s family home (ODNB). The nature of the job has not been discovered.
Francis Maitland Balfour, Arthur James Balfour’s brother, was a lecturer in animal morphology at Cambridge. Arthur John Evans, the son of John Evans, had published a collection of letters sent during 1877, when he travelled in the Balkans for the Manchester Guardian (A. J. Evans 1878). He founded Casa San Lazzaro at Ragusa, Sicily, for the study of language, antiquities, and customs.

## Bibliography

Darwin, George Howard. 1878b. On the bodily tides of viscous and semi-elastic spheroids, and on the ocean tides upon a yielding nucleus. [Read 23 May 1878.] Philosophical Transactions of the Royal Society of London 170 (1879): 1–35.

Darwin, George Howard. 1878e. Problems connected with the tides of a viscous spheroid. [Read 19 December 1878.] Philosophical Transactions of the Royal Society of London 170 (1879): 539–93.

Darwin, George Howard. 1879a. The determination of the secular effects of tidal friction by a graphical method. [Read 19 June 1879.] Proceedings of the Royal Society of London 29: 168–81.

Darwin, George Howard. 1879b. On the secular changes in the elements of the orbit of a satellite revolving about a tidally distorted planet. [Read 18 December 1879.] Philosophical Transactions of the Royal Society of London 171 (1880): 713–891.

Darwin, George Howard. 1881a. On the tidal friction of a planet attended by several satellites, and on the evolution of the solar system. [Read 20 January 1881.] Philosophical Transactions of the Royal Society of London 172: 491–535.

Darwin, George Howard. 1883. On the formation of ripple-mark in sand. [Read 22 November 1883.] Proceedings of the Royal Society of London 36 (1883–4): 18–43.

Darwin, George Howard. 1898.The tides and kindred phenomena in the solar system. London: John Murray.

Evans, Arthur John. 1878. Illyrian letters. London: Longmans, Green, and Co.

Freeman, Richard Broke. 1977. The works of Charles Darwin: an annotated bibliographical handlist. 2d edition. Folkestone, Kent: William Dawson & Sons. Hamden, Conn.: Archon Books, Shoe String Press.

Lyell, Charles. 1851b. A manual of elementary geology; or, the ancient changes of the earth and its inhabitants as illustrated by geological monuments. 3d edition, revised. London: J. Murray.

Movement in plants: The power of movement in plants. By Charles Darwin. Assisted by Francis Darwin. London: John Murray. 1880.

## Summary

Comments on CD’s book [Movement in plants].

Continues with his experiments with ripple-marks.

Is in despair about his astronomy.

## Letter details

Letter no.
DCP-LETT-12828
From
George Howard Darwin
To
Charles Robert Darwin
Sent from
Trinity College, Cambridge
Source of text
DAR 210.2: 87
Physical description
ALS 6pp