Chapter 6—Part 2

Eclecticism, Opportunism, and the Evolution
of a New Research Agenda:
William and Margaret Huggins and the
Origins of Astrophysics

Barbara J. Becker

A Dissertation submitted to The Johns Hopkins University
in conformity with the requirements for the degree of
Doctor of Philosophy
Baltimore, Maryland
1993

Copyright ©1993 by Barbara J. Becker
All rights reserved

CHAPTER 6—PART 2

SOLAR OBSERVATIONS AT TULSE HILL

The Eclipse Expedition to Oran

The next total solar eclipse took place in 1869. It swept across North America from northwest to southeast. No British expedition was sent to observe it. Where attention had been focussed on the solar prominences during the 1868 eclipse, observers participating in the 1869 expeditions were interested in studying the solar corona -- the soft white glow around the limb of the moon during the total phase of a solar eclipse. On some occasions, observers had described the corona as reaching out like asymmetric fingers into the darkened sky, but other times it had escaped any notice at all.

A solar eclipse was predicted for December 1870 which would be visible from sites nearer to European observers than that of 1869. This time, the moon's shadow would sweep nearly west-to-east making landfall briefly at Cabo de São Vicente, Portugal and again at Cadiz, Spain, then moving on to Gibraltar, crossing the Mediterranean Sea to Algeria where it would pass conveniently near the cities of Oran and Tunis. After leaving Africa, the center line would cut across southern Sicily falling midway between the cities of Catania and Syracuse.

William Huggins led a small expedition to Algeria to view the 1870 eclipse with the intention of examining the solar corona spectroscopically. It is the only eclipse expedition in which Huggins played any role and so I shall discuss it in some detail. Participation in this expedition exposed him to the challenges of providing leadership under stress, eliciting group cooperation from a collection of observers accustomed to working independently, obtaining financial support from a tight-fisted liberal Government, and coping with frustration of a clouded-out eclipse.

In 1870, there was still fertile disagreement as to the nature of the solar corona. No one was sure whether the corona was physically connected to the sun, an effect of the terrestrial atmosphere comparable to a mock sun or a tangential arc, or simply an illusion of contrast. Interest in the solar corona was greatly enhanced after the 1868 eclipse in part because of the bounty of information obtained on the nature of solar prominences. Another important factor was the promise held out to solar observers by the new investigative tools of photography, spectroscopy, and polariscopy for achieving an understanding of the nature of other features of the near-solar environment. In addition, there was a suggestive report offered by Dr. Edmund Weiss of Vienna, who had participated in the Austrian eclipse expedition team sent to Aden in 1868. Where others in his party had observed the prominences, Weiss had concentrated on the corona. His results, which he reported in person at the April 1869 meeting of the RAS, startled and intrigued the Fellows present.

Solar enthusiasts had expected that, if the corona were of solar origin, it would either be shown to consist of photospheric light reflected off tiny suspended particles swarming around the sun's visible surface (in which case it would show a continuous spectrum interrupted by the same absorption lines seen in the normal solar spectrum), or it could be a glowing gas of very low vapor density (in which case it would show bright emission lines like the solar prominences). Weiss told the RAS that he had observed a truly continuous spectrum in his examination of the coronal light, a result which he admitted he could not explain, but only report. This observation suggested to Weiss another possible explanation for the corona, namely that it was comprised of a cloud of incandescent solid or liquid particles, a suggestion clearly at odds with current views on the sun's temperature gradient.⁴⁰

The observations made by the American eclipse teams during the 1869 eclipse complicated the matter even more. The corona was quickly proving to be a tangle of challenging puzzles for observers interested in the physics of the sun. William Harkness of the U. S. Naval Observatory, for example, described the coronal spectrum as continuous -- that is, showing no absorption lines -- and crossed by one bright green line. Charles A. Young of Dartmouth College, also noted the presence of a green emission line in the coronal spectrum and determined its location at 1474 on Kirchhoff's scale (5303Å on modern scales), a line very close to one of terrestrial iron. If the prominences were predominately hydrogen, the lightest of the known elements, how could a layer of vaporous iron remain for very long above it? How could temperatures be sufficiently high to cause the incandescence of solid particles at such great distances from the solar surface? In general, the coronal spectrum observed in 1869 stretched the interpretive sophistication of spectroscopic experts beyond the limits for which their experience had prepared them.

Neverthless, reports of this North American eclipse stimulated great interest in Britain among professional and amateur astronomers alike for the Mediterranean eclipse coming in December 1870. George Airy, for example, was impressed by the potential for spectroscopic observation to assist celestial mechanicians in determining the precise time of events such as the first contact of the leading edge of the moon's shadow with the solar limb, events over which there had been dispute by visual observers in the past. In early November 1869, Airy began to press Huggins to participate in an expedition to view the 1870 eclipse in Gibraltar.⁴¹ Amateur interest may have been aroused by a popular article on the American observations of the 1869 eclipse contributed by William Crookes to the January 1870 number of the Quarterly Journal of Science. This article was accompanied by a remarkable full-color illustration of the eclipse during totality (see Figure 34). The next month, a letter from "A Constant Reader" appeared in the Astronomical Register asking if any expeditions to view the 1870 eclipse were being planned by the RAS. If so, the letter continued, "I and certain friends of mine would proceed there." The writer of this letter hinted at a potential windfall for the Peninsular and Oriental Company should they offer reduced fares on transport to Gibraltar since many others like himself would then be encouraged to make private arrangements to see the eclipse. "A total solar eclipse is such a rare phenomenon," he pointed out, "and as none can be seen in Great Britain in the lifetime of anyone now alive, I am sure many lovers of astronomy would wish to proceed where this treat can be obtained."⁴²

Figure 34. Total solar eclipse, 1869 [from Qtly. Jnl. Sci. 7 (1870): 29].

In March 1870, the Council of the RAS began to consider plans for a possible eclipse expedition.⁴³ The Royal Society had already formed a Solar Eclipse Committee in January. In April, the two societies joined forces to constitute a Joint Eclipse Committee with each society contributing £250 to get things started. Much of the discussion at the RAS meeting in April 1870 centered on eclipse preparation and planning.⁴⁴ The RAS President, William Lassell, announced that it seemed probable the Admiralty would furnish a ship to transport a British expeditionary team to a favorable eclipse site, perhaps Jerez north of Cadiz, Oran, or Syracuse. Considerable discussion followed on the relative merits of the proposed observation sites. Gibraltar was given a great deal of support by George Airy and others with experience observing there during the winter months, although Airy warned that travel to the Mediterranean region through the Bay of Biscay was likely to be a treacherous experience and so might limit the numbers of skilled observers inclined to participate. Airy was delegated to request assistance from the Admiralty in the form of two ships for transport, one to Spain and one to Sicily.⁴⁵ He did not relish this task, but he had made initial inquiries in the spring which had received some optimistic response. In recent years, the Admiralty had made ships available to eclipse expeditions, as well as other projects, so there was some hope for success.⁴⁶

William Huggins and others offered expert advice during the meeting. In order to observe both the prominences and the corona spectroscopically, Huggins argued that a total of five spectroscopes would be required at each observing station: "two for the prominences, two for the corona, and one for the outer part of the latter light." To operate each of the first four of these instruments to best advantage would require three individuals: one to observe through the instrument, one to keep the desired object on the slit of the spectroscope, and one to record. The instrument trained on the outer region of the corona would not require guidance, so only an observer and recorder would be necessary. Thus, each station, in Huggins' opinion, would need a minimum of fourteen spectroscopic observers.⁴⁷

Aware of the number of individuals like "A Constant Reader" and his friends who might attempt to sign on to the Society's expedition to obtain a glimpse of the eclipse for their own pleasure and amusement, the discussion ended with the caveat that it be "understood that no mere idle spectators were wanted in the expedition and that those who volunteered would take the parts assigned to them without grumbling."⁴⁸ Warren De La Rue declared, "They must remember they will have no time to look about."⁴⁹

In April, a circular was distributed to all Fellows of the RAS. The response was overwhelming. The Assistant Secretary of the RAS, John Williams, sent to the Royal Observatory a list of those interested in joining the Eclipse expedition. The list included John Browning, Henry Roscoe, Alexander Strange, Huggins, Lockyer, De La Rue among others.⁵⁰ The Joint Eclipse Committee was left with the task of paring down the list of over fifty aspirants. By June, Huggins, as Secretary of the RAS, sent Airy a memo with a short list of principal observers in four investigatory categories. The photographic work would be organized by Warren De La Rue, John Browning and Alfred Brothers of Manchester. Spectroscopy would be in the hands of Huggins, Lockyer and John Gladstone. Polarization observations would be conducted by Airy, Stokes, and Charles Pritchard. A general survey of the eclipse would be directed by William Lassell, Strange and J. H. Dallmeyer.⁵¹

But as the summer progressed, and no word from the Government was received concerning financial and material assistance, hopes for the expedition began to dim. In early August, Airy received the news that the Admiralty would likely refuse the Committee's request.⁵² It looked as though all the preliminary planning had been for naught. "It seems to me doubtful if the exped can be carried out under the present political circumstances," Huggins wrote to Airy.⁵³ Airy was already thinking it best, as he wrote to De La Rue, to "abandon the whole scheme."⁵⁴ De La Rue replied with an alternative suggestion:

I am inclined to think with you that a regular expedition is no longer possible; while, at the same time, if two or more sets of observers are still willing to go out & make specific observations I think that it would be legitimate to aid them out of the sums placed at the disposal of the Committee. The observations most needed are spectroscopic observations of the entities usually confounded with the corona -- also of the corona proper at distances of 1', 2', 3' from the moon's limb, also polariscope observations of the corona.⁵⁵

A worried Huggins wrote to George Stokes: "I fear we shall get no assistance from the Admiralty for the Eclipse Exp. which perhaps will have to be given up. I have called a meeting of the Council R. Ast. S. on Friday, & will write to you after that day." Following his signature, Huggins added: "Could you let me know if, in your opinion, no assistance from Government being obtained, part of the funds of R. S. voted for Exp. could be applied to assist in sending out any observers."⁵⁶ He even tried to persuade Lockyer to attend this special meeting to decide "what steps are to be taken under these circumstances."⁵⁷

Two months later, on 21 October, just as the situation appeared completely hopeless, the Government let it be known that the "question might be reconsidered."⁵⁸ But as De La Rue explained to the Chief Hydrographer, many who had originally expressed interest in participating back in the spring had made other plans. If only the Government had given more timely word that the question was still open, the expedition might have been saved; however, at this late date, in De La Rue's view, it was better to simply "let the matter drop."⁵⁹

Nevertheless, the matter did not drop, in large part due to Lockyer's connections, efforts and drive.⁶⁰ Lockyer wrote a searing editorial in Nature which blasted the Joint Eclipse Committee for its inept handling of the whole affair. He singled out Huggins whose inability to keep members of the Committee informed on matters shortly to come before them was, in Lockyer's opinion, emblematic of the larger problem of mismanagement in the Committee. Lockyer concluded his tirade by pointing out, "There is still ample time to organise an expedition which shall do much good work, though perhaps it is too late to send out and erect the largest class of instruments."⁶¹

Late on 11 November, word was received that the Government would provide a ship to Spain, Gibraltar and Oran as well as £2000 for the Sicilian expedition's land transportation. The news was announced at the RAS meeting that very evening. An anxious three weeks followed as individuals scurried to prepare themselves for the journey. On 6 December, William Huggins, his eclipse party, and others planning to view the eclipse from sites en route, set sail on the Urgent, an aptly named ship, provided by the Government.⁶² It had been fitted for the trip in just under a week and was known by those who had sailed it before for its propensity to roll violently.

In chapter 3, I mentioned that William Crookes, a member of Huggins' party, kept a diary of this expedition.⁶³ Crookes' first entries contain details of the hazardous journey experienced by the eclipse travellers as their ship crossed the Bay of Biscay on its way to Cadiz. As Airy had feared, a fierce storm at sea caused serious damage to the ship and tossed its not-too-seaworthy occupants around their cabins.⁶⁴

Following stops at Cadiz and Gibraltar to drop off the other two observing parties, Huggins and his group continued on to Oran which port they reached on 16 December.⁶⁵ The next day, Huggins and a few of the group went ashore to locate an appropriate site for the eclipse observatory. They found an ideal spot conveniently near the railway station providing them with access to telegraph services. Stormy weather raised concern over the prospects for the eclipse, but in a few days the weather cleared giving the observers an opportunity to work with their instruments.

Crookes complained that his spectroscope had been "roughly put together" and his telescope, a 4-1/2 inch Grubb refractor, had no clockwork. To ready his instrument for the spectroscopic observations he was to make during the course of the eclipse, Crookes removed the telescope's eyepiece and inserted the spectroscope. This spectroscope was structured somewhat like Lockyer's sunspot spectroscope described earlier, an instrument which had become more or less standard for solar spectroscopists by that time. But it had one important new feature: it had been specially designed by Huggins to allow its user to register the observed positions of spectral lines automatically.

Reports from observers of recent eclipses impressed solar spectroscopists with the need to automate the process of recording the locations of spectral lines during totality. Much time was routinely lost removing one's eye from the eyepiece of the spectroscope to note the reading on the head of the micrometer screw as each spectral line passed over the crosshairs. The eye had to accommodate each time from distance to near vision in order to make an accurate reading. In addition, viewing a faint spectrum in the spectroscope required a satisfactory level of dark adaptation. Unfortunately, reading the micrometer exposed the observer's eyes to light. During a normal spectroscopic observation, an object could be kept in view for an extended period of time with the principal hazard being eye fatigue experienced by the observer repeatedly going back and forth between the eyepiece and the micrometer. There is no such leisure during eclipses. Not only that, but with the corona as the object of prime interest, the spectrum to be observed was expected to be extremely faint. Uninterrupted dark adaptation was an absolute necessity to heighten the observer's visual acuity and thus insure that every detail possible was recorded.

Just days before the eclipse, Lieutenant Brown, a member of Lord Lindsay's party, a privately sponsored expedition team planning to observe the eclipse from Maria Luisa Observatory in Cadiz, became concerned about the need for some way to make an automatic record of spectroscopically observed phenomena during totality. He immediately "set to work to construct a recorder, and fitted it to the spectroscope, which, as will be hereafter seen, worked very well. Indeed, I know of no other mode of measuring the position of lines quickly that I would adopt during an eclipse."⁶⁶ Unfortunately, Brown provided little information in his eclipse report as to the design or method of use of this recorder. The only clue given suggests that he generated a comparison strip on which were marked the principal Fraunhofer lines. This strip was positioned in such a way as to be visible in the spectroscope. As Brown described it, following first contact and the occultation of a number of sunspots, "I fitted and adjusted my spectroscope, and carefully recorded the position of the solar lines ... both above and below the spaces left for corona and prominence observations by means of my automatic recording arrangement."⁶⁷ During totality, Brown observed only a faint continuous spectrum with no absorption lines or emission lines in spite of looking especially hard for signs of the green line at 1474 on Kirchhoff's scale.

Huggins had also anticipated the special challenge of spectroscopic observation under the pressure of a total eclipse, but he had done his thinking about the problem before he left England and so was able to provide the solar spectroscopists on his eclipse team with a fairly sophisticated automatic recording device attached to their instruments. On consultation with Howard Grubb, who was, in late 1870, building the telescope paid for by the Royal Society for Huggins' use, Huggins contrived an ingenious but simple device capable of permitting the observer to note the position of each spectral line observed without ever removing his eye from the eyepiece.⁶⁸ Crookes described it in this way: "At the eye end of the spectroscope is an arrangement for rapidly bringing a pointer on to any line in the spectrum and pricking its position on a card."⁶⁹

Huggins' practical observing experience told in the design of this recording instrument. There were two needles which could be operated separately allowing the observer to indicate if the particular line being noted was an emission line (by pressing only one needle) or an absorption line (by pressing both needles). Each card was made so that five separate spectra could be recorded in succession before replacing it with a new one. This device was later improved upon by others,⁷⁰ so Huggins' initial contribution has been somewhat obscured over time, particularly as his party were unable to put the instrument to good use during the eclipse. Crookes, for one, spent considerable time before the eclipse practicing with this new device.

The day of the eclipse, each observer set up his equipment and readied himself for the rush of totality. Crookes again practiced using the recording device on his spectroscope. He consulted with Huggins and Reverend Howlett (who would be guiding Crookes' telescope during the eclipse) as to just how they would proceed with the coronal observations during the little more than two minutes they would have of totality. The aim was to record three critical views of the coronal spectrum: placing the spectroscope radially on the trailing limb of the moon (just before totality), placing the spectroscope tangential to the moon's limb in the lowest region of the corona (during totality), and finally aiming the spectroscope at some region of the corona some distance away from the moon in order to get a view of the streamers (once again during totality).

Crookes planned to cover his eyes just before totality to increase his light sensitivity. During these important coronal observations, he was to be on the alert for Fraunhofer lines, extra black lines, and the bright green line noted by Young and Harkness in 1869. Like modern Olympian lugers, these men committed their motions to autonomic kinesthetic memory. Timing, coordination, and precision were everything.⁷¹ At around 11 a.m., Crookes spotted the small bite out of the sun's disk which signaled the start of the eclipse. It also signaled the start of the invasion of clouds which obliterated all hope of making any but the most general observations. Their painstaking practice all for naught, the observers reluctantly left their instruments and concentrated instead on gross changes in light and color in their surroundings. Shortly after totality, Crookes and Noble sent telegrams to the Daily News and the Times with the report of their failure. "As soon as the telegrams had been sent," Crookes wrote in his diary, "we returned to the tents, and after standing for one or two photographs commenced to take the instruments down and pack them up, for after our failure but one idea seemed to possess all, and that was to get away from Oran and on our homeward voyage as quickly as possible."⁷²

Lockyer had no better luck with the weather at his station in Catania, Sicily. But a number of others had more success including the American astronomer, Charles Young, who reported viewing for the first time, the bright lines of the sun's reversing layer.⁷³ Lord Lindsay, who had financed his own eclipse expedition to Cadiz, Mr. Brothers who viewed the eclipse in Syracuse, and Mr. Willard from the United States who was also located at a site near Cadiz, all obtained photographs showing the corona. The general shape of the corona in the photographs conformed in general appearance to sketches made by Lieutenant Brown in Lord Lindsay's group at the Maria Luisa Observatory in Cadiz (see Figure 35).

Figure 35. Woodcut from colored drawing of the solar corona seen from Cadiz during total solar eclipse, December 1870, by Lieut. Brown [from Mon. Not. Roy. Soc. 31 (1871): 56].

The observations made during the eclipse of 1870 by those individuals blessed with clear skies during totality contributed but little to solving the corona puzzle. For one thing, the increasing numbers of people reporting their observations of the same celestial event, and the disparity of their representations, brought into greater relief the risks of relying on visual observations alone. The instrumentation, the interpretive skills of the fledgling corps of astronomical spectroscopists, and the photographic capabilities available at the time were simply not up to the task of recording the faint corona. Speculation as to the nature and structure of the solar corona flourished, and encouraged the development of improved mechanical observing and recording techniques.⁷⁴

In the final analysis, the Report of the Council to the annual RAS meeting in February 1871 contended that,

Although the gain to our knowledge of Solar physics is much less full and decided than doubtless it would have been if the very efficiently equipped and competent observers had been favoured with a cloudless sky, the new information which comes to us from the eclipse is very valuable, and well repays the large amount of thought, time, and money, which were so freely bestowed upon the preparations.⁷⁵

However, when it came time to provide support for a British team to observe the upcoming eclipse in India in December 1871, the RAS committee appointed to weigh the question showed considerably less enthusiasm. Lockyer, the only one to continue to press for support, finally received what he wanted through the intervention of the British Association.⁷⁶

Organizing eclipse expeditions was a risky business that required a great deal of money and ambition. Few individuals had the money to mount their own expeditions. Even those, like Huggins, who questioned whether the Government should provide financial support for the running of national astrophysical laboratories, argued for the need for the Government to underwrite such intensive research efforts. Nevertheless, as a leader of an observing party which had used Government resources yet brought back nothing in return, Huggins must have harbored latent doubts as to the efficacy of expending so much time, energy, and money on such hit-or-miss ventures. He never participated in another eclipse expedition. In fact, his interest in solar observation returned to its old occasional pace for the rest of the 1870s.

But his earlier work on observing solar prominences without an eclipse and his party's failure to observe the eclipse of 1870, made him receptive to a choice bit of information following another eclipse in 1882. Based on this information, Huggins was encouraged to attempt a bold plan for photographing the solar corona without an eclipse. As we shall see in the next section, his initial success in this project led him to pursue it for many years with great zeal and conviction. In the end, it tested the strength of his persuasive power and encouraged him to build an international network of confirmatory witnesses. I shall argue that, contrary to commonly held views about Huggins' minimal participation in solar research, in an important way, Huggins' confidence that the outer atmosphere of the sun could be studied without an eclipse helped to shape the methods of solar observation that were developed, the types of questions being asked about the solar atmosphere, and the direction in which solar observation was taken up to the turn of the century.

NOTES
[click on footnote number to return to text]

40. Dr. Edmund Weiss, presentation of results of 1868 solar eclipse expedition, Astronomical Register 7 (1869): 100-3.

41. George Biddell Airy to William Huggins, 5 November 1869, RGO 6.271/7/2/303, University of Cambridge Library.

42. "A Constant Reader," February 1870, Letter to the Editor of the Astronomical Register 8 (1870): 58-9.

43. J. L. E. Dreyer, H. H. Turner, et al., History of the Royal Astronomical Society 1820-1920 (Blackwell Scientific Publications: Oxford, 1987; originally published Wheldon & Wesley: London, 1923): 169.

44. Discussion of the plans for the Eclipse Expedition in December 1870, Astronomical Register 8 (1870): 99-105.

45. Ibid.

46. In 1860, the Admiralty furnished the Himalaya to transport Warren De La Rue, George Airy and others to the eclipse in Rivabellosa, Spain. See, Smith, "The Heavens Recorded, 7; Pang, Spheres of Interest, 28-30. In 1868, the Lightning, a paddle steamer, was made available to William Benjamin Carpenter and Charles Wyville Thomson by the Admiralty for a deep-sea dredging project in the North Atlantic. In 1869, the Porcupine was provided to them for the collection of biological specimens off the cost of Ireland and Shetland. See, Marie Boas Hall, All Scientists Now: The Royal Society in the Nineteenth Century (Cambridge University Press: Cambridge, 1984): 175.

47. "Discussion of the plans for the Eclipse Expedition in December 1870, Astronomical Register 8 (1870): 99-105; 103.

48. For a discussion of the social aspects of eclipse expeditions and their planning, see Pang, Spheres of Interest, chapter 3, 85-146.

49. Ibid., 104. Just before the eclipse parties were scheduled to depart, Huggins, wrote a last minute letter to Airy to express his lingering concern for the intrusion of what he referred to as a whole "host of men looking through a telescope for the first time." It was Huggins' opinion that the interests of science would best be served if each eclipse party were kept as a small, well-trained group. Airy tartly responded in agreement, "I absolutely protest against taking hunters of the picturesque." See, William Huggins to George Airy and George Airy to William Huggins, 19 November 1870, RGO 6.132/5/130-1, University of Cambridge Library. Airy had used nearly the same words ten years earlier to ward off would-be eclipse observer, Joseph Beck, an observer who had wanted to accompany Warren De La Rue on his eclipse expedition to Spain in 1860. See Pang, Spheres of Interest, 29.

50. John Williams to E. J. Stone, 19 May 1870, RGO 6.131/1/14, Airy papers, University of Cambridge Library.

51. William Huggins to George Airy, 23 June 1870, RGO 6.131/1/38, Airy papers, University of Cambridge Library.

52. Pang, Spheres of Interest, 38.

53. William Huggins to George Airy, 5 August 1870, RGO 6.131/2/52, Airy papers, University of Cambridge Library.

54. George Airy to Warren De La Rue, 5 August 1870, cited in Pang, Spheres of Interest, 38.

55. Warren De La Rue to George Airy, 6 August 1870, RGO 6.131/2/54, Airy papers, University of Cambridge Library.

56. William Huggins to George Stokes, 16 August 1870, Add MS 7656.H1124, Stokes papers, University of Cambridge Library.

57. William Huggins to J. Norman Lockyer, 16 August 1870, Lockyer papers, University of Exeter Library.

58. George Airy to the Editor of the Daily News, 14 November 1870, published in Astronomical Register 8 (1870): 257-8; 257.

59. Warren De La Rue to George Airy, 25 October 1870, RGO 6.131/2/65, Airy papers, University of Cambridge Library.

60. For a discussion of the complexities of expedition organization, see Dreyer, Turner, et al., History of the Royal Astronomical Society, 169; Meadows, Science and Controversy, 66-7; and Pang, Spheres of Interest, 38-41.

61. J. Norman Lockyer, Nature, 2 (1870): 13.

62. The Urgent carried three eclipse parties. The first, headed by the Reverend S. J. Perry planned to view the eclipse at Cadiz, Spain. A second party, headed by Captain Parsons was going to Gibraltar. The third party, led by Huggins (including Admiral Erasmus Ommaney, John Tyndall, Reverend Frederick Howlett, James Carpenter, Captain William Noble, John H. Gladstone, William Crookes, and others) was travelling on to Oran in Algeria. The Sicilian group headed by Lockyer planned to travel over land to Naples where they would then proceed by ship to Sicily.

63. Edmund E. Fournier d'Albe, The Life of William Crookes (T. Fisher Unwin: London, 1923): 135-73. Simon Newcomb's wife also kept a personal diary of her journey to Gibraltar with her husband's eclipse party. Unfortunately, she did not fare well during her stay aboard the Urgent and spent almost the entire trip in her quarters. Thus, it contains little which sheds any light on Huggins or his eclipse expedition. See, Simon Newcomb papers, Diary of Mrs. Newcomb, Box 2, Library of Congress. [Box 1 contains a partial typewritten transcript of this particular diary which documents her first trip to Europe.]

64. The following excerpts from Mrs. Newcomb's diary convey the discomfort of this journey: 7 December 1870, "[I tried to go below] grasping the rail, but it broke and flung me to the bottom. I was up in a minute but my head ached severely in consequence"; 8 December, "I kept in bed"; 9 December, "I was up a little, but worse"; 10 December, "Had so much pain and was so tired of the confinement.... Really three miserable days...."

65. Crookes recounted a humorous anecdote about Huggins to make the point that Huggins was vulnerable to visual suggestion. As the Urgent approached what the crew believed to be the city of Cadiz, Huggins took out a small telescope and observed a pilot ship approaching them. Crookes wrote: "'There's Lord Lindsay,' cried Huggins.... The man came alongside, when, instead of Lord Lindsay, he turned out to be a seedy-looking pilot who could not speak English." See d'Albe, Life of William Crookes, 151.

66. Lieutenant Brown, "Report of Observations of the Solar Eclipse," Monthly Notices of the Royal Astronomical Society 31 (1871): 52-9; 52.

67. Ibid., 54.

68. William Huggins, "On a Registering Spectroscope," Proceedings of the Royal Society 19 (1871): 317-8.

69. d'Albe, Life of William Crookes, 156.

70. John W. Draper, an American physician and amateur astronomer, came up with an idea for registering spectral lines which he believed was, as he described it, "infinitely beyond" the card pricking system devised by Huggins. The elder Draper strongly suggested to his son, Henry, that he develop this invention quickly since he considered "this the most important improvement in the spectroscope that has yet been made." John William Draper to Henry Draper, 15 August 1875, Draper papers, New York Public Library. I wish to thank Dr. Howard Plotkin for bringing this letter to my attention.

71. This sort of preparation tempered natural excitability during totality and united human control with instrumental capabilities for optimum performance. In an article on the 1869 solar eclipse in Burlington, Iowa, Crookes himself had recounted the testimony of Dr. Mayer, a photographer from Philadelphia: "I had nothing but an instrumental consciousness, for I was nothing but part of the telescope, and all my being was in the work I had to perform." Unfortunately, Mayer's efficiency left him with 50 seconds of totality to spare and no more photographic plates at the ready! See, William Crookes, "The Total Solar Eclipse of August Last," The Quarterly Journal of Science 7 (1870): 28-43; 43.

72. d'Albe, Life of William Crookes, 161.

73. The so-called solar "reversing layer" had been predicted, but not observed. Theoretically, the layer of the sun's upper atmosphere which produces the dark Fraunhofer lines in sunlight coming from the solar disk should produce an emission spectrum which precisely mirrors the sun's absorption spectrum when observed spectroscopically at the limb of the sun. The brilliance of the solar disk and the thinness of this layer contribute to the difficulty in seeing it. During the 1870 eclipse, for example, Young reported having seen the reversing layer's bright-line spectrum for only two seconds.

74. For a summary and discussion of the range of speculations being put forth shortly after the 1870 eclipse, see Richard A. Proctor, "Theoretical considerations respecting the corona, Parts I and II," Monthly Notices of the Royal Astronomical Society 31 (1871): 184-94; 254-62.

75. "The Total Solar Eclipse, Dec. 22, 1870," Report of the Council, Monthly Notices of the Royal Astronomical Society, 31 (1871): 111-7; 113.

76. For a discussion of the events leading up to the eclipse of 1871, see Meadows, Science and Controversy, 68-9.

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