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Images of the sun: Warren De la Rue, George Biddell Airy and celestial photography

Published online by Cambridge University Press:  05 January 2009

Holly Rothermel
Holly Rothermel
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330 Musketaquid Road, Concord, MA 01742, USA.
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Extract

By the early years of the twentieth century, astronomers regarded photography as one of the most valuable tools at their disposal, a technique which not only provided an accurate and reliable representation of astronomical phenomena, but also radically changed the role of the astronomical observer. Herbert Hall Turner, professor of astronomy at Oxford, wrote in 1905: ‘The wonderful exactness of the photographic record may perhaps best be characterised by saying that it has revealed the deficiencies of all our other astronomical apparatus – object-glasses and prisms, clocks, even the observer himself.’ H. C. Russell, government astronomer in Sydney, suggested that photography might in the future make the observer redundant: ‘In many cases the observer must stand aside while the sensitive photographic plate takes his place and works with the power of which he is not capable… I feel sure that in a very few years the observer will be displaced altogether.’ Such visions were not uncommon at the time, emanating from the trust invested in the photographic process after the spectacular achievements of the late nineteenth century.

Type
Research Article
Information
The British Journal for the History of Science , Volume 26 , Issue 2 , June 1993 , pp. 137 - 169
Copyright
Copyright © British Society for the History of Science 1993

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References

The Airy Papers of the Royal Greenwich Observatory Archives are cited courtesy of the Syndics of Cambridge University Library and of the Director of the Royal Greenwich Observatory. The Herschel Letters and other papers from the Royal Society Archives are cited courtesy of the Royal Society.

A portion of this research was done in preparation for an M.Phil, thesis at Cambridge University in 1988; subsequent work was done in 1991. I would like to thank Adam Perkins, curator of the Royal Greenwich Observatory Archives, for his assistance with the Airy Papers, Jim Bennett and Michael Dettelbach for their helpful comments, and especially Simon Schaffer, for his advice and encouragement.

1 Airy, George Biddell to De la Rue, Warren, 24 09 1857Google Scholar, Royal Greenwich Observatory, Airy Papers, box 169, fols. 549–50.

2 De la Rue, Warren, ‘Presidential Address to British Association for the Advancement of Science, Section A’, in Report of the 42nd Meeting of the British Association for the Advancement of Science, 1872, 11.Google Scholar

3 Turner, Herbert Hall, ‘Some reflections suggested by the application of photography to astronomical research’, Popular Astronomy (1905), 13, 78.Google Scholar

4 Russell, H. C., ‘Progress of astronomical photography’, Popular Astronomy (1894), 2, 101.Google Scholar

5 The first stellar spectrum was photographed by Henry Draper in 1872.

6 Owing to lack of enthusiasm in many of the twenty-one observatories involved, the project was never finished. The factual information in this paragraph can be found in either of the two most comprehensive accounts of the history of astronomical photography: de Vaucouleurs, Gérard, Astronomical photography, London, 1961Google Scholar; and Norman, Daniel, ‘The development of astronomical photography’, Osiris 1938, 5, 560–94.CrossRefGoogle Scholar

7 Gelatine was first added to collodion by Dr Richard Leach Maddox; the principle of his formula is still used today. See Lemagny, Jean-Claude and Rouillé, André (eds.), A History of Photography: Social and Cultural Perspectives (tr. Lloyd, Janet), Cambridge, 1986, 270.Google Scholar

8 Turner, Herbert Hall, Modern Astronomy: Being Some Account of the Revolution of the Last Quarter of a Century, Westminster, 1901, 60.Google Scholar

9 Berger, John, ‘Uses of photography’, in About Looking, London, 1980, 48.Google Scholar

10 See for instance Sontag, Susan, On Photography, Middlesex, 1978Google Scholar; Barthes, Roland, Camera Lucida: Reflections on Photography (tr. Howard, Richard), London, 1982Google Scholar; and Szarkowski, John, The Photographer's Eye, London, 1980Google Scholar. Also Freund, Gisele, Photography and Society, London, 1980.Google Scholar

11 A recent collection of essays by John Tagg does mention some earlier examples of the social effects of photography, discussing its use in relation to the police, psychiatry and slum clearance projects: The Burden of Representation: Essays on Photographies and Histories, London, 1988.Google Scholar

12 The best general histories of photography are: Helmut, and Gernsheim, Alison, History of Photography, London, 1969Google Scholar; Newhall, Beaumont, The History of Photography, London, 1982Google Scholar; and Lemagny, and Rouillé, , op. cit. (7).Google Scholar

13 There are numerous accounts of the ‘spurious’ use of photography for such purposes as the diagnosis of insanity. The subject appears in most histories and theories of photography, probably because of the obvious social commentary involved. See Tagg, , op. cit. (11)Google Scholar, Lemagny, and Rouillé, , op. cit. (7).Google Scholar

14 Some exceptions: Crowe, Michael J. gives a valuable discussion of visual and photographic controversy surrounding the canals of Mars in The Extraterrestrial Life Debate 1750–1900: The Idea of a Plurality of Worlds from Kant to Lowell, Cambridge, 1986, see pp. 480–546Google Scholar; and Rudwick, Martin presents an excellent examination of the visual language of geology in ‘The emergence of a visual language for geological science, 1760–1840’, History of Science (1976), 14, 149–95CrossRefGoogle Scholar. Hetherington, Norriss, in Science and Objectivity: Episodes in the History of Astronomy, Ames, 1988Google Scholar, and Sheehan, William, in Planets and Perception, Tucson, 1988Google Scholar, also discuss the problematic nature of astronomical observation, with some discussion of the role of the photograph.

15 Darius, Jon, Beyond Vision, Oxford, 1984, 19Google Scholar. See Shapin, Steven, ‘The politics of observation: cerebral anatomy and social interests in the Edinburgh phrenology disputes’, in On the Margins of Science: The Social Construction of Rejected Knowledge (ed. Wallis, Roy), Keele, Staffs., 1979, 139–78Google Scholar, for an excellent discussion of the way in which interests influence observation.

16 Lynch, Michael, ‘Discipline and the material form of images: an analysis of scientific visibility’, Social Studies of Science 1985, 15, 37–66.CrossRefGoogle Scholar Lynch says: ‘By “material” I mean sensible, analyzable, measurable, examinable, manipulatable and “intelligible”’ (p. 43).Google Scholar

17 ‘Obituary Notice’, Monthly Notices of the Royal Astronomical Society (1889–1890), 50, 163Google Scholar. There is no biography of De la Rue. Besides the above-mentioned, the biographical data presented in this paper came from the following sources: Hartog, P. J., ‘Rue, Warren De la’, DNB, 1964Google Scholar; Williams, L. Pearce, ‘De la Rue, Warren’, DSB, 1970Google Scholar; and Dreyer, J. L. E. and Turner, H. H. (eds.), The History of the Royal Astronomical Society 1820–1920, London, 1923Google Scholar, chapters 4 and 5. See also Lankford, John, ‘The impact of photography on astronomy’, in Astrophysics and Twentieth-Century Astronomy to 1950 (ed. Gingerich, Owen), Cambridge, 1986, 16–39.Google Scholar

18 Lankford points out that as the status of amateur astronomers in Britain rapidly declined as the field became more theoretical and mathematical, photography remained an area where amateurs were able to contribute great amounts, and that by the last third of the century, the only amateurs who received awards from the Royal Society were photographers. Lankford, John, ‘Amateurs vs. professionals: the controversy over telescope size in late Victorian science’, Isis 1981, 72, 11–28.Google Scholar

19 ‘To Mr Warren De la Rue belongs the honour of having obtained the earliest results of substantial value in celestial photography.’ Clerke, Agnes M., A Popular History of Astronomy During the Nineteenth Century, 2nd edn, Edinburgh, 1887, 193.Google Scholar

20 De la Rue, Warren, ‘Note in reference to a drawing of Saturn’, Monthly Notices of the Royal Astronomical Society (1851–1852), 12, 14Google Scholar. See Smiles, Samuel (ed.), James Nasmyth – Engineer – An Autobiography, London, 1885, 373Google Scholar, for De la Rue's introduction to astronomy.

21 ‘Notice’, Monthly Notices of the Royal Astronomical Society (1850–1951), 11, 165Google Scholar. The daguerrotypes by Bond and Whipple were taken with the 15 inch equatorial refractor at Harvard, and the images of the moon obtained were 5 inches in diameter. Vaucouleurs, , op. cit. (6), 19–20.Google Scholar

22 Lemagny, and Rouillé, , op. cit. (7), 20Google Scholar. For a discussion of Herschel's involvement in photography see Schaaf, Larry, ‘Sir John Herschel's 1839 Royal Society paper on photography’, History of Photography (1979), 3, 47–60CrossRefGoogle Scholar and Schaaf, Larry, ‘Herschel, Talbot and photography, spring 1831 and spring 1839’, History of Photography 1980, 4, 269–70.CrossRefGoogle Scholar

23 ‘On fera une sorte d'oeil artificial en plaçant une lentille entre le prisme et l'écran où tombera le spectre, et l'on cherchera en suite, fût-ce même à láide d'une loupe, la place des raies noires de l'image photogénique par rapport aux raies noires du spectre lumineux.’ Arago, François, ‘Le daguerrotype’, Ouevres de François Arago, 2nd edn., 17 vols., Paris, 1865, vii, 500–1Google Scholar, fn 1.

24 Vaucouleurs, , op. cit. (6), 13–14.Google Scholar

25 Bond and Whipple produced the first photographs of stars in 1850, H. Fizeau and L. Foucault, of Paris, made the first successful daguerrotype of the sun in 1845, and J. W. Draper, an American physiologist, secured the first photograph of the solar spectrum in 1843. See Norman, , op. cit. (6), 591Google Scholar, and Vaucouleurs, , op. cit. (6), 18–21.Google Scholar

26 See Lemagny, and Rouillé, , op. cit. (7), 20–7Google Scholar; and Vaucouleurs, , op. cit. (6), 14–16Google Scholar; for technical information.

27 Although Hippolyte Fizeau did develop a method of direct engraving from daguerrotype plates in 1842, this method was relatively complicated and never perfected. Lemagny, and Rouillé, , op. cit. (7), 27.Google Scholar

28 Lemagny, and Rouillé, , op. cit. (7), 20–7.Google Scholar

29 Lee, John, ‘Address delivered by the President, Dr Lee, on presenting the Gold Medal of the Society to Mr Warren De la Rue’, Monthly Notices of the Royal Astronomical Society (1861–1862), 22, 135.Google Scholar

30 This was accomplished either by locating a crater in the cross-wires of the telescopic field and following it with the telescope, or by moving the photographic plate on a sliding platform. ‘Obituary Notice’, op. cit. (17), 158.Google Scholar

31 ‘Notice’, Monthly Notices of the Royal Astronomical Society (1857–1858), 18, 16.Google Scholar

32 He hoped that the observatory at Cranford would offer him ‘the advantage of a purer atmosphere than London offered, and of a driving clock which is ready to be attached to the telescope’, De la Rue, to Herschel, , 11 05 1857Google Scholar, Royal Society, Herschel Letters, vol. 6, no. 139. The machinery De la Rue used is painstakingly described in ‘How Mr Warren De la Rue photographed the moon’, The Engineer, 22 05 1868, 574–6.Google Scholar

33 Herschel, to De la Rue, , 10 10 1858Google Scholar, Royal Society, Herschel Letters, vol. 6, no. 143.

34 Schaffer, Simon, ‘Astronomers mark time’, Science in Context (1988), 2, 119CrossRefGoogle Scholar. See also Meadows, A. J., Greenwich Observatory, Volume 2, 3 vols., London, 1975.Google Scholar

35 Brooke, Charles, ‘On the automatic registration of magnetometers, and other meteorological instruments, by photography’, Phil. Trans. 1847, 137, 59–77.CrossRefGoogle Scholar

36 Airy, George Biddell, ‘Remarks on the application of photography’, Monthly Notices of the Royal Astronomical Society (1857–1858), 18, 17.Google Scholar

37 Cannon, Susan Faye, Science in Culture: The Early Victorian Period, New York, 1978, 159Google Scholar. See also Schaffer, Simon, ‘Experimenting with Objectives: Table-Top Trials in Victorian Astronomy’Google Scholar, unpubl. manuscript, pp. 3–8, for a discussion of the Comtian thesis about astronomy, and the reaction to it in Britain.

38 Krauss, Rolf H., ‘Photographs as early scientific book illustrations’, History of Photography (1978), 2, 291.CrossRefGoogle Scholar

39 See Ivins, William, Prints and Visual Communication, Cambridge, 1969Google Scholar; for one of the best discussions of printing processes and issues of representation.

40 Rudwick, , op. cit. (14), 151.Google Scholar

41 De la Rue, to Herschel, , 12 10 1856Google Scholar, Royal Society, Herschel Letters, vol. 6, no. 137.

42 De la Rue, to Herschel, , 13 10 1856Google Scholar, Royal Society, Herschel Letters, vol. 6, no. 138.

43 The development of the eclipse expedition was closely related to the geomagnetic expeditions of the early nineteenth century. See Cannon, , op. cit. (37)Google Scholar. Also see Clerke, , op. cit. (19), 76–88Google Scholar for a discussion of the eclipse of 1836.

44 Daily, Francis, ‘On a remarkable phenomenon that occurs in total and annular eclipses of the sun’, Memoirs of the Royal Astronomical Society (1838), 10, 6.Google Scholar

45 Clerke, , op. cit. (19), 77.Google Scholar

46 Royal Greenwich Observatory, Airy Papers, box 112, fol. 60.

47 Baily, Francis, ‘Some remarks on the total eclipse of the sun, on July 8th, 1842’, Memoirs of the Royal Astronomical Society (1846), 15, 4.Google Scholar

48 Airy, quoted in Meadows, , op. cit. (34), 89.Google Scholar

49 Baily, , op. cit. (47), 209.Google Scholar

50 Herschel, to Airy, , 15 12 1850Google Scholar, Royal Greenwich Observatory, Airy Papers, box 119, fols. 194–5.

51 Talbot, Fox to Airy, , 2 05 1851Google Scholar, Royal Greenwich Observatory, Airy Papers, box 119, fol. 500.

52 Airy, to Talbot, Fox, 3 05 1851Google Scholar, Royal Greenwich Observatory, Airy Papers, box 119, fols. 502–3.

53 Ranyard, A. C., Observations Made During Total Eclipses, Memoirs of the Royal Astronomical Society (1870), 41, 489Google Scholar. Ranyard compiled this volume at the suggestion of Airy, and it included all written eclipse observations made up until 1871.

54 Airy, George Biddell, ‘Account of the total eclipse of the sun on 1851, July 28, as observed at Göttenburg, at Christiania, and at Christianstadt’, Memoirs of the Royal Astronomical Society (1851), 21, 24.Google Scholar

55 Airy, , op. cit. (54), 6.Google Scholar

56 Airy, , op. cit. (54), 5 and 12.Google Scholar

57 Reverend Baden-Powell, , ‘On the beads in the solar eclipse’, Memoirs of the Royal Astronomical Society (1851), 21, 116–17.Google Scholar

58 Assmus, Alexi and Galison, Peter, ‘Artificial clouds, real particles’, in The Uses of Experiment: Studies in the Material Sciences (ed. Gooding, David et al. ), Cambridge, 1989, 225–74.Google Scholar

59 Reverend Powell, Baden, ‘Communication from Reverend Baden Powell’, Monthly Notices of the Royal Astronomical Society (1839–1843), 5, 264.Google Scholar

60 Airy, George Biddell and Nasmyth, James, ‘Notice’, Memoirs of the Royal Astronomical Society (1853), 22, 243.Google Scholar

61 Nasmyth, to Airy, , 30 08 1851Google Scholar, Royal Greenwich Observatory, Airy Papers, box 113, fol. 127.

62 Norman Lockyer, P. J. C. Janssen and William Muggins almost simultaneously introduced a method for spectroscopically viewing the prominences without an eclipse in 1868, but it was not until the twentieth century that a method for observing the corona was developed. See Meadows, A. J., Science and Controversy: A Biography of Sir Norman Lockyer, London, 1972, 51–8.Google Scholar

63 Herschel, J. F. W., quoted in Monthly Notices of the Royal Astronomical Society (1852–1853), 13, 567.Google Scholar

64 Herschel, to Sabine, , 24 04 1854Google Scholar, printed in Monthly Notices of the Royal Astronomical Society (1854–1855), 15, 158Google Scholar. See Clerke, , op. cit. (19)Google Scholar, part I, ch. 3, for a good discussion of Herschel and the investigation of sunspots.

65 The Kew Observatory originally had been a government observatory, but the government ceased maintenance of it in 1841. It was offered to the Royal Society, who refused it. The observatory was taken up instead by the British Association and transformed into a centre for magnetic and meteorological measurements. Sabine was an instrumental figure in this transfer, and served on the Kew Committee for many years. See Meadows, , op. cit. (62), 123.Google Scholar

66 ‘Report of the Kew Committee’, Report of the 24th Meeting of the British Association for the Advancement of Science, 1854, pp. xxxvii–xli.Google Scholar

67 De la Rue, Warren, ‘Report on the present state of celestial photography in England’, Report of the 29th Meeting of the British Association for the Advancement of Science (1859), 150.Google Scholar

68 Photographs of the sun had been taken before. The first was probably obtained in 1842, while Fizeau and Foucault, at the instigation of Arago, captured the first clear image in 1845. J. B. Reade made the first collodion print in 1854. The Kew project was the first attempt at a systematic photographic record. See Vaucouleurs, , op. cit. (6), 18–19.Google Scholar

69 ‘Report of the Kew Committee’, Report of the 27th Meeting of the British Association for the Advancement of Science, 1857, p. xxxv.Google Scholar

70 De la Rue, , op. cit. (67), 150–1.Google Scholar

71 See De la Rue, to Herschel, , 15 09 1858Google Scholar, Royal Society, Herschel Letters, vol. 6, no. 142.

72 Airy, to Bond, G. P., 5 09 1857Google Scholar, Royal Greenwich Observatory, Airy Papers, box 169, fol. 546. G. P. Bond was the son of William Cranach Bond, and succeeded him as director of the Harvard Observatory.

73 See Schaffer, , op. cit. (34)Google Scholar, and Bennett, Jim, ‘George Biddell Airy and horology’, Annals of Science (1980), 37, 269–85CrossRefGoogle Scholar, for discussions of this instrument.

74 Bond, G. P. to Airy, , 27 09 1857Google Scholar, Royal Greenwich Observatory, Airy Papers, box 169, fol. 554.

75 Airy, to De la Rue, , 24 09 1857Google Scholar, Royal Greenwich Observatory, Airy Papers, box 169, fols 549–50.

76 de la Rue, Warren, ‘The Bakerian Lecture – on the total solar eclipse of July 18th, 1860, observed at Rivabellosa, near Miranda de Ebro, in Spain’, Phil. Trans. (1862), 152, 334.CrossRefGoogle Scholar

77 De la Rue, , op. cit. (76), 334.Google Scholar

78 De la Rue, , op. cit. (76), 334.Google Scholar

79 De la Rue, , op. cit. (76), 334.Google Scholar

80 De la Rue, , op. cit. (76), 334.Google Scholar

81 Talbot, Fox to Airy, , 14 05 1851Google Scholar, Royal Greenwich Observatory, Airy Papers, box 119, fols. 506–7.

82 De la Rue, , op. cit. (76), 336.Google Scholar

83 Airy, George Biddell, ‘Account of observations of the total solar eclipse of 1860, July 18, made at Hereña, near Miranda de Ebro; with a notice of the general proceedings of “The Himalaya Expedition for Observation of the Total Solar Eclipse”’, Monthly Notices of the Royal Astronomical Society (1860–1861), 21, 3.CrossRefGoogle Scholar

84 Airy, to De la Rue, , 29 05 1860Google Scholar, Royal Greenwich Observatory, Airy Papers, box 123, fol. 268.

85 The biography of Vignoles written by his son provides an informal account of the expedition of 1860: Vignoles, Olinthus J., Life of Charles Black Vignoles, London, 1889.Google Scholar

86 De la Rue, Letter to Faraday, M., 25 04 1861Google Scholar, reprinted in The Selected Correspondence of Michael Faraday (ed. Williams, L. Pearce), vol. 2, Cambridge, 1971.Google Scholar

87 De la Rue, , op. cit. (76), 360.Google Scholar

88 De la Rue, , op. cit. (76), 339.Google Scholar

89 De la Rue, to Airy, , 08 1860Google Scholar, Royal Greenwich Observatory, Airy Papers, box 123, fol. 284.

90 De la Rue, Warren, ‘Comparison of Mr De la Rue's and Padre Secchi's eclipse photographs’, Proceedings of the Royal Society (1863–1864), 13, 442Google Scholar. As Gombrich, E. H. points out, ‘a print is not even a “mere” transcript of the negative’Google Scholar. There is room for personal influence everywhere. See Gombrich, E. H., Art and Illusion: A Study in the Psychology of Pictorial Representation, reprint, Oxford, 1987.Google Scholar

91 Royal Astronomical Society, ‘Report on the eclipse of 1860’, Monthly Notices of the Royal Astronomical Society (1860–1861), 21, 116.Google Scholar

92 De la Rue, , op. cit. (76), 340.Google Scholar

93 Airy, to De la Rue, , 31 10 1860Google Scholar, Royal Greenwich Observatory, Airy Papers, box 123, fol. 310.

94 De la Rue, , op. cit. (76), 368.Google Scholar

95 De la Rue, to Airy, , 24 08 1860Google Scholar, Royal Greenwich Observatory, Airy Papers, box 123, fol. 287.

96 Airy, to De la Rue, , 27 08 1860Google Scholar, Royal Greenwich Observatory, Airy Papers, box 123, fol. 296.

97 Airy, to De la Rue, , 27 03 1861Google Scholar, Royal Greenwich Observatory, Airy Papers, box 123, fols. 339–40.

98 Stokes, G. G., ‘Report on Mr Warren De la Rue's paper on the solar eclipse of July 18, 1860’, 14 07 1862Google Scholar, Royal Society, Referee's Reports, vol. 4, no. 66.

99 Stokes, , op. cit. (98).Google Scholar

100 ‘What should we now say of the early Fellows of the Royal Society, if they had relegated Newton, when he invented the telescope that bears his name, to the company of Spectackle [sic] Makers for his meed of praise?’ Lee, , op. cit. (29), 139.Google Scholar

101 Nasmyth, James, Memoirs of the Literary and Philosophical Society of Manchester, 3rd series (1861), 407Google Scholar. See also Smiles, op. cit. (20), 370–80.Google Scholar

102 Smiles, , op. cit. (20), 371.Google Scholar

103 In an extensive article on the willow-leaf controversy, C. F. Bartholomew points out that Herschel's enthusiasm was partly due to the fact that the willow leaves would agree with his own observations about the sun. The willow-leaf theory explained two phenomena in his theory of the sun: the solid filaments were capable of giving off luminosity (it was thought at the time that gases were not luminous), and their sharp outlines accounted for the sharp borders between the photosphere and the sunspots. See Bartholomew, C. F., ‘The discovery of the solar granulation’, Quarterly Journal of the Royal Astronomical Society (1976), 17, 263–89.Google Scholar

104 Reverend Dawes, W. R., ‘Some remarks on the telescopic appearance of the exterior envelope of the sun, and of its spots’, Monthly Notices of the Royal Astronomical Society (1863–1864), 24, 33.Google Scholar

105 De la Rue, to Herschel, , 26 08 1861Google Scholar, Royal Society, Herschel Letters, vol. 6, no. 147.

106 Reverend Dawes, W. R., ‘Further remarks on the telescopic appearance of the exterior envelope of the Sun, and of its spots’, Monthly Notices of the Royal Astronomical Society (1863–1864), 24, 55.Google Scholar

107 Muggins, William, ‘Results of some observations on the granules of the solar surface, with remarks on the nature of these bodies’, Monthly Notices of the Royal Astronomical Society (1865–1866), 260–5.Google Scholar

108 Lockyer, Norman, ‘On the physical constitution of the sun’, The Reader (1865), 5, 107Google Scholar. Also see Meadows, , op. cit. (62)Google Scholar, for Lockyer's role in the controversy.

109 The first series of papers, written between 1865 and 1868, was concerned with specific determinations of the characteristics of sunspots. While De la Rue co-authored the papers with Bernard Loewy, hired in 1864 to help with the reduction and measurement of the sunspot photographs, and Balfour Stewart, the director of the Kew Observatory, he did the writing himself.

As a result of these papers, the Kew observers became embroiled in a controversy with the French astronomer Faye over the structure of sunspots. This controversy, and the various theories about sunspots and the solar constitution that were proposed in the 1860s are beyond the scope of this paper. See Meadows, op. cit. (62).Google Scholar

110 The second series of papers was: (1) ‘Researches on solar physics. Heliographical positions and areas of sun-spots observed with the Kew photoheliograph during the years 1862 and 1863’, Phil. Trans. (1869), 159, 1–110Google Scholar; (2) ‘Researches on solar physics – no. II. The positions and areas of the spots observed at Kew during the years 1864–66, also the spotted area of the sun's visible disk from the commencement of 1832 up to May 1868’, Phil. Trans. (1870), 160, 384–496Google Scholar; and (3) ‘Researches on solar physics III’, rec. 12 03 1872Google Scholar, Royal Society Assorted Papers, vol. 55, no. 4.

111 Herschel, J. W., ‘Referee's Report’, 6 06 1869Google Scholar, Royal Society, Referees' Reports, vol. 6, no. 101. See also Thomson, William, ‘Referee's Report’, 1 06 1870Google Scholar, Royal Society, Referees' Reports, vol. 7, no. 28, and Airy, George Biddell, ‘Referee's Report’, 23 05 1872Google Scholar, Royal Society, Referees' Reports, vol. 7, no. 165.

112 De la Rue, et al. , (1869), op. cit. (110), 1.Google Scholar

113 De la Rue, et al. , (1872), op. cit. (110), 2.Google Scholar

114 ‘Those preceding parts had definite objects which were completely worked out; of the observations bearing on the question of depth of solar spots, on the positions of the faculae, on the influence of Venus and Jupiter, on the effect of solar Latitude, and some other points.’ Airy, , op. cit. (111)Google Scholar. The paper was none the less recommended for publication, but De la Rue discovered an error in Loewy's calculations, and he had to cancel the paper. It is now available only in manuscript form.

115 Airy, George Biddell, ‘On the means which will be available for correcting the measure of the sun's distance in the next 25 years’, Royal Astronomical Society Monthly Notices (1856–1857), 17, 156–7.Google Scholar

116 Carpenter, J., ‘British preparations for the approaching transit of Venus’, Nature (1872), 5, 178.CrossRefGoogle Scholar

117 De la Rue, to Airy, , 2 11 1871Google Scholar, Royal Greenwich Observatory, Airy Papers, box 271, fols. 168–9.

118 Carpenter, , op. cit. (116), 178.Google Scholar

119 See Airy, (ed.), ‘Appendix V. Photographic observations of the transit of Venus’, in Account of Observations of Transit of Venus 1874, Dec. 8, London, 1881, 14–19.Google Scholar

120 Abney, Captain, ‘On the photographic operations connected with the coming transit of Venus’, Nature (1874), 6, 449–50Google Scholar. See also de Abney, Captain W., ‘Dry plate process for solar photography’, Royal Astronomical Society Monthly Notices (1873–1874), 34, 273–8.Google Scholar

121 A controversy about the best way of recording the transit caused intense squabbling between Airy and a leading member of the Royal Astronomical Society. Airy wished to view the transit by Delisle's method, which involved securing local times of ingress or egress. R. A. Proctor claimed that the method would prove inadequate and that Halley's method, which involved a measure of total duration, should be used. Airy reluctantly agreed to use both. See Meadows, , op. cit. (34), 45–6.Google Scholar

122 Carpenter, , op. cit. (116), 178.Google Scholar

123 This occurred when Venus crossed the limb of the sun; a black neck was seen between the round planet and the limb of the sun. See Forbes, George, ‘The transit of Venus’, Nature (1874), 7, 28–30.Google Scholar

124 Forbes, , op. cit. (123), 29.Google Scholar

125 Tupman, Captain, Astronomical Register (1877), 15, 312.Google Scholar

126 Tupman, Captain, ‘On the photography of the transit of Venus’, Monthly Notices of the Royal Astronomical Society (1877–1878), 38, 508.CrossRefGoogle Scholar

127 Airy, quoted in Common, A. A., ‘Photography as an aid to astronomy’, 1886Google Scholar, reprinted in Lovell, Bernard (ed.), The Royal Institution Library of Science: Astronomy, London, 1970, 246.Google Scholar

128 Airy, , op. cit. (119), 18.Google Scholar

129 ‘Royal Astronomical Society Meeting’, Astronomical Register (1878), 18, 174.Google Scholar

130 ‘The transit of Venus’, The Daily News, 19 01 1875Google Scholar, Royal Greenwich Observatory, Airy Papers, box 280, fol. 144.

131 Airy, to Christie, William, 16 01 1878Google Scholar, Royal Greenwich Observatory, Airy Papers, box 271, fol. 259.

132 Airy, to De la Rue, , 14 01 1878Google Scholar, Royal Greenwich Observatory, Airy Papers, box 271, fols. 252–3.

133 Airy, to Rutherford, Lewis, 1 11 1865Google Scholar, Royal Greenwich Observatory, Airy Papers, box 681, fols. 344–5.