Eclecticism, Opportunism, and the Evolution
of a New Research Agenda:

William and Margaret Huggins and the
Origins of Astrophysics

by

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 3—PART 1

MOVING IN THE INNER CIRCLE

In the last chapter, I described how William Huggins' discovery of emission lines in some nebular spectra won him an honored place in the community of serious amateur astronomers as well as election to Fellowship in the Royal Society. This successful application of spectroscopic methods to a new class of celestial objects raised important methodological and theoretical questions for practicing astronomers, both amateur and professional.  In particular, it increased the growing fuzziness of disciplinary boundaries defining the traditional limits of acceptable astronomical research in the mid-nineteenth century.

Huggins' reminiscences later in life focus on the success of a few key pioneering contributions from his early career and give the impression that all, or much, of his subsequent work centered on the spectroscopic study of stellar and nebular objects.  An examination of contemporaneous documents does not bear this out.  I shall argue instead that Huggins showed a dynamic eclecticism in his selection of subject and method which is both characteristic of an avid and skilled amateur and emblematic of the methodological and theoretical diversity to be found in the astronomical community during that period.  He shunned repetitive observations of a single class of celestial event or object and thus avoided becoming trapped in a narrow line of investigation which would have lessened his opportunities for making new discoveries.1

While Huggins could have set himself the arduous task of examining the spectrum of every known nebular object, or systematically cataloguing the spectra of northern hemisphere stars.  Instead, he chose to pursue a varied and opportunistic research program like many other amateur astronomers of his day, devoting considerable time and serious attention to research problems generated by others, and to the exotic rather than the mundane.  His interests were broad and his curiosity led him to explore a number of different subjects in innovative and often technically challenging ways.  Huggins' status as an independent observer freed him from the obligation or commitment of a more traditional research program which restricted contemporary institution-bound observers.  His challenge was to maximize his exposure to opportunities for new discoveries without becoming identified as a speculative or impulsive dilettante.

I shall also argue that during this phase of his career, Huggins developed a reputation for his care in making observations and his caution in suggesting explanations for the phenomena he observed.  His successes led to more opportunities for success.  Huggins became recognized as one upon whom noted telescopic observers such as the venerable director of the Armagh Observatory, Thomas Romney Robinson, and the Astronomer Royal, George Biddell Airy, could rely for advice on spectroscopic matters.2  He cultivated his alliances to great personal advantage, eventually earning for himself selection as the custodian of a state-of-the-art telescope paid for with funds appropriated by the Royal Society.

Cultivating Advantageous Alliances

Shortly after Huggins' election to Fellowship in the Royal Society in June 1865, he was called upon to verify a report made by the Vatican astronomer, Father Angelo Secchi.  Secchi, who, like Huggins, had begun to incorporate spectroscopic observation into his astronomical research program, had called attention to what he claimed was an unusual red star.3  About the same time, Huggins received a similar request to examine the star from Thomas Romney Robinson.  Nine months later, William Huggins sent a belated response to Robinson:

In June 1865 you wrote to me from Sir J. South's to ask me to look at a red star, the spectrum of which was described by Secchi "as consisting exclusively of the less refrangible rays"....  The star was not at that time in a position to be observed.  Last evening I examined the light of this star with the spectroscope.4

Robinson and Huggins were members of two largely non-intersecting circles of astronomers.  Separated by age, geography and observational interests, the two men had little in common to bring them together.  Recall that in early 1864, Robinson's attention was drawn to Huggins' work through the latter's publications in the journals of the Royal Society.  His favorable referee report on Huggins' chemical spectra paper conveyed a clear sense that he viewed Huggins as sharing his own concern for precision and reliable measurement.  Shortly after Huggins' election to the Royal Society, the elderly and more experienced Robinson paid a visit to the Tulse Hill observatory seeking the advice of his younger colleague on spectroscopic matters.5

When, on the evening of 6 March 1866, Huggins was at last able to examine the star in question, he informed Robinson that he disagreed with Secchi's conclusions.6  By the time Huggins' letter arrived, however, Robinson's interest in Secchi's star had apparently waned.  His more pressing concern in 1866 was the construction of the controversial 48-inch Melbourne reflecting telescope so that sky surveys of the southern hemisphere could begin in earnest.  A contract had just been signed with the Dublin-based instrument maker, Thomas Grubb, to make a four-foot Cassegrain telescope.7  Robinson was excited about the plans for this telescope whose construction he had long advocated.8  He wanted it to have every modern astronomical convenience:  Not only would the telescope boast remarkable resolution capabilities comparable to that of Lord Rosse's six-foot Leviathan, but it would have special attachments for photographic work and spectroscopy which would rival the best known at the time.

Thus, Huggins' long-delayed response on Secchi's red star may have come too late to satisfy Robinson's curiosity on a matter of fleeting concern, but it caught him at an opportune moment as he considered the construction of a state-of-the-art instrument.  Being reminded of Huggins' spectroscopic experience at just this time may have provided Robinson with an excuse to tap the younger man's expertise as preparations were underway to complete work on the great Melbourne telescope. Perhaps a plea for assistance from Robinson prompted Huggins to write again on 13 March, this time with a list of suggestions for fitting up the "great Southern reflector" for spectroscopic work.9

The tone of these letters to Robinson suggests a growing maturity in Huggins' professional sense and provides tangible evidence of the seriousness with which he viewed his work.  The information he provided Robinson was rudimentary and practical -- designed to communicate the kind of tacit information required to reduce frustrating, yet often unavoidable, trial and error in equipment arrangement and thus facilitate observation.  Ordinarily this information is gained by the give and take of direct verbal exchange or personal demonstration.  Huggins was unable to show Robinson in person how best to arrange the apparatus, but he could describe it in plain language and bolster it with the kind of rationale a man of Robinson's experience could appreciate:  "With a little practice," Huggins counseled Robinson, "the irregularities of the clock may be compensated for in part by varying the pressure of a finger placed against the eye-tube."10

Huggins' advice was later sought on spectroscopic apparatus for other projects as well.  In the fall of 1866, for example, a committee of the Royal Society was formed and £200 was put at its disposal in order to establish an astronomical and meteorological observing station in India.  Guidance was sought on how best to spend this grant.  "Many of those most competent to judge," Vice-President and Treasurer William Allen Miller wrote to President Edward Sabine, "are agreed that a powerful telescope provided with a suitable spectroscope would be a most valuable thing under a competent and permanent observer at the present time."11  Huggins, along with John Herschel and George Stokes, was among the experts consulted.  After the spectroscopic instruments had been constructed, Lieut. John Herschel, the elder astronomer's son, who was to oversee their operation in India, visited Huggins' Tulse Hill observatory in order to gain instruction in their proper use.12  Thus, we see that soon after his election to Fellowship in the Royal Society, Huggins had become identified as a valued resource by a small but influential circle of experienced observers and his advice was actively sought as others hoped to make their instrumentation capable of contributing to the collection of spectroscopic information on celestial bodies.  That this advisory relationship continued well into the next decade can be inferred by the exchange of letters between William Huggins and William Christie, Chief Assistant at the Royal Observatory at Greenwich and future Astronomer Royal.  Christie requested Huggins' advice on the apparatus needed to institute a program of regular spectroscopic observations.13  Cultivating these alliances worked to Huggins' advantage, as I will show later in this chapter.

Opportunism and Eclecticism

In this section, I shall bring to light evidence of Huggins' investigative eclecticism during this phase of his career.  Among his many research interests in the late 1860s, the one for which he is best known today is his innovative development of a method and technique for determining a star's motion in the line of sight through spectroscopic observation.  The central place which this valuable research tool holds in the toolkit of modern professional astronomers has resulted in considerable attention being drawn to Huggins' pioneering role in its early development.  But, as I shall show, the focus on Huggins' line-of-sight investigations -- a focus initiated and encouraged by Huggins himself -- has tended to overshadow, and, in fact, even obscure, his other eclectic astronomical projects during this period, which demonstrate his breadth of interest and drive to diversify even after he had found a successful line of inquiry.

In March 1866, Huggins began a new notebook.  Its title page is not as elaborate as that of his first one.  It merely says in large script letters: "Observatory-Book, 1866."  The motto of the RAS is written below in smaller hand.14  The first thirteen pages contain lists and descriptions of instruments and lists of visitors to the observatory, including the names of some prominent individuals whose visits occurred in 1859, 1860 and 1865, before the notebook was started.15

The entries in this notebook have a different character from those of the first notebook.  For one thing, they are more complete.  Huggins provides a little more background information in each entry as to observing conditions and instrumentation employed.  He even includes occasional interpretive remarks.  Still, there are many gaps which cannot be accounted for -- observations claimed in published papers for which no notebook record can be found and long periods with no observations and no explanation.

The form and variety of those observations Huggins did record in his new notebook indicate that in spite of his growing expertise in astronomical spectroscopy, he still eschewed a program which concentrated on a single type of object or methodological approach in favor of one which left him free to explore whatever interested him at any given time.  He monitored a number of different celestial objects on an irregular basis throughout 1866:  the surface of the sun, the spectra of various nebulae, and the spectra of stars which had been brought to his attention by others concerned about the cause of some unusual feature of the star's appearance.  That he had no rigid observing schedule can be inferred from the fact that whenever he was notified of something new or unusual in the sky, he immediately subjected it to scrutiny.  He was also tolerant of visitors to his observatory, some of whom were simply neighbors or friends wishing to see the moon through a telescope.  In the following sections, I shall enumerate several of Huggins' diverse research projects undertaken during the late 1860s, including his efforts to determine stellar motion in the line of sight using spectrum analysis, to provide an indication of the breadth of his investigative interests during that period.

The Nova in Corona Borealis

On 14 March 1866, Huggins recorded his first notebook entry related to celestial spectroscopy.  Of the fifteen observations he noted during the next two months, only six involved examination of nebulae.  The rest included observations of the moon, the sun, various stars and one examination of the effect of aperture on the size of the ring visible around the telescopic image of a star.  But in mid-May, an unexpected celestial event temporarily gripped Huggins' attention.  Alerted to the appearance of a nova in the constellation Corona Borealis by an Irish amateur astronomer, Huggins acted immediately on the astronomer's suggestion to subject the nova's light to spectrum analysis.  The identification of this nova as a member of a class of variable stars which undergo long-term periodic fluctuations in brightness focussed the attention of variable star observers on the results of Huggins' spectroscopic examination of this one celestial body.

On 18 May 1866, Huggins wrote to John Herschel:

Mr. W. Huggins presents his compliments to Sir John Herschel and thinks that the information which follows may perhaps be interesting to him.

On the 16th inst Mr. Huggins received a letter from Mr. John Birmingham of Tuam, stating that the writer saw on Saturday the 12, a new star of the 2d magnitude near Corona Bor.16

The formality of this letter gives some indication of the social and generational distance between the two men.  The eminent Herschel, then 74 years old, was one of the few surviving charter members of the RAS.  Herschel had a long-standing interest in the variability of celestial objects.  His observation of the sudden outburst of the southern hemisphere star then known as h Argûs (now h Carinae) in December 1837, for example, is a case in point.17  Huggins moved quickly not merely to notify the elder astronomer of the star's appearance, but more importantly, to apprise Herschel of his unprecedented spectroscopic study of the nova in Coronae Borealis.

Stellar outbursts bright enough to be seen with the naked eye have rarely been noted.  There are practical reasons for this.  Those classified today as true supernovae are indeed rare:  By modern estimates, only about three or four such events occur, on average, in any given galaxy during a millennium.  These dazzling stars appear with remarkable suddenness, often rivalling the brighter planets in brilliance and occasionally remaining visible during daylight hours.  Their luminosity fades slowly but steadily over a period of twelve to eighteen months.

By contrast, it is now accepted that regular novae occur with relative frequency -- as many as thirty or forty may burst forth in our galaxy each year. Assuming this rate to be constant over time, we can account for the lack of attention given to novae in the past by noting that their small increase in brightness makes them less likely to reach naked eye visibility.  Additionally, the increase in luminosity is of such short duration that the entire event can be obscured by a week or two of overcast sky, or washed out by sun- or moonlight.  Even under ideal conditions, registering such an event requires that someone is watching and is watching with an eye willing to recognize what is seen as indicative of change in the heavens.18

The nineteenth century witnessed an increase in the number of amateur astronomers, an increase in telescopic power available to them, and an interest in noting and measuring variability in celestial objects.  The likelihood of someone observing an event of this type was much greater than ever before.  In 1848, John Russell Hind, for example, noted the brightening of a previously unobserved star in Ophiucus.  This was not a dazzling event and it drew but little attention from anyone other than a handful of astronomers.  In 1863, Norman Pogson, a veteran observer of variable stars, observed and charted the changes in brightness of U Scorpii for three weeks before it faded to virtual invisibility.  Even at its brightest, that nova was so dim and of such short duration that no one other than Pogson seems to have noted it.19

Observers like Hind, Pogson, and Birmingham were part of a handful of astronomers who were intrigued by the problem presented by stars like o Ceti (Mira) and b Persei (Algol) whose brightnesses fluctuate with some degree of predictability.  Other variable stars tantalized them because of their idiosyncratic behavior.  One such star was R Coronae, which variable star observers were watching with some interest in 1866.20  It may not have been totally coincidental, then, that the appearance of a new star in the same constellation within a few degrees of R Coronae should be observed independently by several individuals at about the same time, including a Mr. Barker in London, Ontario who claimed to have sighted the nova on 4 May.

Birmingham sent a letter from his home in Galway to the London Times announcing his discovery.21  Fearing the letter might not be published, he sent another directly to Huggins which arrived about 5 o'clock on Wednesday evening, 16 May 1866.  Birmingham believed the new star would make an interesting subject for spectroscopic analysis and chose to alert Huggins to its discovery as soon as possible.22  Just two hours after Birmingham's note arrived, Huggins received a similar letter from the experienced variable star observer, Joseph Baxendell of Manchester.23

The suddenness of Birmingham's announcement would have caught Huggins far less prepared had it not been for a fortuitous sequence of events which brought the problem of variable stars to Huggins' attention shortly before the nova made its appearance.  A few months earlier, in February 1866, Father Secchi had written a letter to the RAS, addressed to the Secretary, but including remarks intended specifically for Huggins.24  In 1865, a similar letter from Secchi drew Huggins into contentious discussion of his interpretive differences with Secchi on nebular spectra.25  This time, Secchi wished to draw the Society's (read, Huggins') attention to a discrepancy in the positions of the spectral lines he had observed recently in the spectrum of a Orionis (Betelgeuse) and those ascribed to them some two years earlier by Huggins in his Philosophical Transactions paper on stellar spectra. Secchi suggested that the observed difference might be due to some physical change within the star.  Betelgeuse already had a reputation as an irregular variable star. Although astronomers had noted only subtle changes in the star's visual appearance of late, a dramatic increase in its luminosity was reported as recently as 1852.  If the luminosity of a star was subject to variations, then, Secchi reasoned, it was possible that its spectrum could change as well.

Secchi's letter was read at the RAS meeting on 9 March 1866, at which time Huggins was called upon by the President, Charles Pritchard, to respond.26  Huggins, thus put on the spot, declined to make more than a few general comments, but did submit a statement for publication later in the Monthly Notices after taking the time to check once again the star's spectrum.27  Setting aside for the moment the harsh criticisms of Secchi's instrumentation and methods contained in Huggins' paper and turning instead to the matters concerning the star's variability, we learn that just a few weeks before the appearance of the nova in Corona Borealis, Huggins, with the help of his neighbor, William Allen Miller, was busy re-examining Betelgeuse's spectrum in search of any evidence for change.  We also learn that one of the two investigators (probably Huggins) wrote to Baxendell to ascertain the current phase of the star's variation.  This put Huggins in contact with Baxendell at an auspicious time.  As a result of information received from Baxendell, Huggins undertook a brief investigation of the spectrum of a second red variable star, m Cephei (William Herschel's "Garnet Star").

Thus, while the nova in Corona Borealis appeared without any advance warning, Huggins' investigations into the spectral signatures of variable stars in the weeks immediately preceding the nova's appearance readied his mind and his method to deal with this new problem.  That variable stars were seen as an appropriate model for novae stemmed from the growing suspicion at that time that all novae were examples of variables with greater or shorter periods.28  Thus the new star in Corona Borealis was quickly dubbed T Coronae by the Astronomer Royal, where the roman letter "T" identifies it as a previously unrecorded star and the third variable found in the constellation.29

The sky was clear on the evening Huggins received the letters from Birmingham and Baxendell.  He took advantage of the time remaining before darkness fell to invite Miller to join him in observing the new star spectroscopically. Together, they prepared the spectroscope and arranged a sodium comparison spectrum.  In short order they were ready to go.  After sighting the new star, Huggins noted, and Miller confirmed, that the nova's spectrum was compound, that is, comprised of a series of bright lines superimposed on a virtually continuous background.  Huggins attributed the continuous spectrum broken by absorption lines to the body of the star and likened the general appearance of the spectrum to that of the variable m Cephei which he had recently observed.30  Huggins believed the bright lines were produced by glowing hydrogen gas and drew attention to what appeared to him to be a nebulous region immediately surrounding the star.

The monthly Royal Society meeting was scheduled for the very next day. Huggins and Miller wasted no time preparing a brief paper describing their preliminary observations of the nova's spectrum.31  Miller's official responsibilities to the Society warranted his attendance.  Huggins, on the other hand, chose to stay at home on the evening of the 17th in order to make direct comparisons of the new star's spectrum with that of hydrogen.32  He invited another friend, a Mr. Kincaid, to observe with him.  Already, the star's luminosity had dropped to near the limit of unaided human vision.  The comparison of the spark spectrum with that of the new star confirmed in Huggins' mind his suspicion that the bright lines emitted by the star coincided with those produced by hydrogen but he was less certain about the nebulosity seen around the star the night before.

On Friday, 18 May, Huggins attended Charles Pritchard's talk at the Royal Institution on the construction of telescopes.33  He recorded in his notebook that he was only able to observe the increased dimness of T Coronae by eye on his way home.34  Over the next week, Huggins made observations every evening, even though the waxing moon coupled with the star's growing dimness made it a difficult object to see.  Henry Acland of Oxford, Joseph Baxendell and Henry Roscoe visited Huggins' observatory and caught a glimpse of the spectrum of the new star.  Kincaid and Miller made return visits, but as the star grew fainter, and the evening hours grew shorter, Huggins returned to objects of routine interest:  the solar surface and various nebular spectra.  After the initial flurry of activity attending the announcement of T Coronae, Huggins recorded only four more observations of the nova between 28 May and 13 September 1866, in his notebook.

During the summer of 1866, Huggins devoted his attention to developing ways of describing and explaining his observations of the nova to others, both in and outside the astronomical community.  He gave a brief report to the RAS, at the request of the Society's President, Charles Pritchard, at its next meeting following the new star's appearance.  The Fellows of the RAS expressed great curiosity and wonder at the news of Huggins' novel spectroscopic observations of T Coronae.35 In addition to relating the objective details of his observations, Huggins ventured to present, for the first time, his creative speculation that the nova's unusual spectrum which included both dark absorption lines (interpreted by many as associated with a celestial body sharing many of the sun's physical characteristics) as well as bright emission lines (accepted as indicative of luminous gas), signified what Huggins referred to as a "star on fire."  This star, by virtue of some cataclysmic event, he suggested, had let loose a large quantity of hydrogen gas into the region immediately surrounding it.  In Huggins' view, the intense heat of the star had ignited the gas which was consumed in a short period of time -- hence explaining the sudden rise and rapid decline in the nova's luminosity -- and then returned to its original, pre-outburst state of extremely low brightness.

In July 1866, Huggins authored an article which appeared in the Quarterly Journal of Science entitled, "On a Temporary Outburst of Light in a Star in Corona Borealis."36  This article, written for an informed lay audience, provided the reader with a brief history of other spectacular stellar outbursts and then repeated the account presented earlier to the RAS of the cause for the sudden increase in this star's brightness.  Huggins pointed out that he was only able to provide an explanation for the nova's change in brightness because of his careful spectroscopic examination of the star's light.  It was widely accepted that this star was not really new in the literal sense of the word, but only recently noticed.  With that in mind, Huggins posed the provocative question of what the star's spectrum might have been like just before the outburst occurred.

On 24 August 1866, Huggins delivered an evening address at the annual meeting of the British Association at Nottingham.37  While he titled the address, "On the Results of Spectrum Analysis Applied to the Heavenly Bodies," and included information on the application of spectroscopy to a variety of celestial objects, he devoted considerable attention to his spectroscopic examination of the new star in Corona Borealis, presenting in it essentially the same information he had given in the Quarterly Journal.38

Even though Huggins no longer referred to the nova as an example of a "star on fire," the phrase must have captured Pritchard's imagination.  In an article for the popular magazine, Good Words entitled "A True Story of the Atmosphere of a World on Fire," the RAS President credited Huggins and Miller with the observation that founded the emerging hypotheses on the cause of stellar outbursts.39 Thus, Pritchard introduced both Huggins and Miller to a far wider audience than might otherwise have had access to their work.40

Huggins' interest in the nova picked up briefly again in September 1866 following Baxendell's report that the star had suddenly brightened once again, but by early October, Huggins reported, "Not brighter certainly -- appeared about the same as on Sept 28....  I saw nothing remarkable."41  Even if there had been something to note, the star was moving quickly into the western twilight and would soon be unobservable.  Huggins turned his attention to more accessible variables Algol and Mira, bright stars with reasonably well-established periods that were high in the autumn sky.  He also examined g Cassiopeiae, a star which Secchi claimed showed bright lines in its spectrum.42

The example of g Cassiopeiae presented a personal challenge to Huggins. His attention was drawn to this star by an article written by Angelo Secchi which was reprinted in the Astronomical Register.43  At the article's conclusion, Secchi had amended his earlier statement about Betelgeuse's variability to say that his own further examination of other variables now led him to fear there was a "positive defect" in Huggins' earlier drawing of the spectrum of Betelgeuse.  In addition, Secchi noted that the bright line he had identified earlier in the star's spectrum now seemed to be surrounded by dark bands.  This latter comment gave rise in Huggins' mind to the possibility that the brightness observed was only an illusion brought on by the contrast of an isolated region of the continuous spectrum surrounded by two dark absorption bands.  Enthused on the one hand by the prospect of finding bright lines in the spectrum of an apparently stable star, Huggins nonetheless remained skeptical of Secchi's observations in general.  As Huggins' notebook entries demonstrate, this skepticism caused him to waiver back and forth on the interpretation of Secchi's bright line claim.  Following his first observation of g Cassiopeiae on 8 October, Huggins noted "A bright line sharply defined in the red. There is a faint shading on both sides.  I am almost certain, that the brightness does not arise from constrast [sic], I think it may be considered a bright line....  Mr. Kincaid present & saw the star."44

The next time Huggins observed, he looked at Algol and the unusual variable star b Lyrae.  According to Secchi, b Lyrae showed a similar pattern to that seen in g Cassiopeiae.  But Huggins was unable to confirm this.  He looked once again at g Cassiopeiae with his direct vision spectroscope and saw the bright red line.  He reported, "This [red line] however falls exactly in a space between absorption lines. Still doubtful if truly a bright line....  These bright lines are less marked with increased dispersion.  I was much impressed with necessity for caution."45

At this point in Huggins' career there is subtle evidence that he was generally predisposed to find fault with Secchi's claims.  This is brought into greater relief when one compares Huggins' struggle with Secchi's bright line claims in this instance with his ready public confirmation of similar findings in other stars reported by Wolf and Rayet of the Paris Observatory.  The initial uncertainty Huggins expressed in his notebook record concerning his observation of Wolf's and Rayet's stars is hidden from public view.46

The bright lines which had appeared in T Coronae sparked Huggins' imagination and spawned his first speculative scheme to explain the process at work in the course of the event being witnessed.  Proper interpretation of the spectral signature, he believed, should lead to an understanding of the causes of variation in stellar luminosity.  If a non-varying star could be observed with bright lines in its spectrum, perhaps a larger chain of events could be described tying nebulae, novae and stars together in some progressive scheme.47

NOTES
[click on footnote number to return to text]

1. This is not to say that Huggins' contributions to large-scale projects being conducted by others was insignificant.  David DeVorkin has discussed Huggins' participation while theories of stellar evolution were developing based on competing systems of stellar classification.  See David DeVorkin, An Astronomical Symbiosis: Stellar Evolution and Spectral Classification (1860-1910), Ph.D. dissertation, University of Leicester, 1978, especially chapter 2.

2. In fact, it is because of the eminence of his correspondents that a number of his letters from this phase of his career survive and are readily accessible.

3. William Huggins, 13 June 1865, MM 16.55, Royal Society Library.

4. William Huggins to Thomas Romney Robinson, 7 March 1866, Stokes papers, Add MS 7656.TR66, University of Cambridge Library.

5. "Visitors to the Observatory, 1865" in Notebook 2.  A date of 3 June or July can be inferred since Robinson's visit is noted in between a visit by the Earl of Rosse and his son, Lord Oxmantown on 26 May and the 29 July visit of Otto Struve.

6. Huggins to Robinson, 7 March 1866.

7. The signing of this contract in late February 1866, concluded nearly four years of argument over the design of the telescope.  See T. R. Robinson and Thomas Grubb, "Description of the Great Melbourne Telescope," Philosophical Transactions 159 (1869):  127-161:  135; J. A. Bennett, Church, State and Astronomy in Ireland 200 Years of Armagh Observatory (The Armagh Observatory: Armagh, 1990):  130-132.

8. Not all astronomers shared Robinson's enthusiasm.  John Herschel, for example, did not approve of mounting the telescope equatorially, that is, aligning its principal axis parallel to that of the earth's rotation.  He feared the telescope's clockdrive would generate image-distorting vibrations and argued for a more traditional horizon-based altazimuth mount claiming "there must be no daring experiment incurring risk of failure."  Letter from John F. W. Herschel to Edward Sabine, 10 December 1862, published in Royal Society, Correspondence concerning the Great Melbourne Telescope.  In three parts:  1852-1870.  Printed, for private circulation only, by order of the Council of the Royal Society (London, 1871):  II, 19-21; cited in Bennett, Church, State and Astronomy in Ireland, 131.  Bennett provides a summary of the history of the Melbourne telescope in this account (pp. 130-4), which is a welcome elaboration on the meager discussion provided in Henry C. King, The History of the Telescope (Charles Griffin & Company Limited: London, 1955):  264-7.  For Robinson's views on the equatorial mount, see, Dr. Robinson to the Earl of Rosse, 28 December 1852, cited in Royal Society, Correspondence, 13-5.

9. This is surmise, however, as only Huggins' letters to Robinson survive in the Stokes collection at the University of Cambridge.  See, William Huggins to Thomas Romney Robinson, 13 March 1866, Add MS 7656.TR67, Stokes papers, University of Cambridge Library.

10. Ibid.

11. William Allen Miller to Edward Sabine, 29 August 1866, Stokes papers, Add MS 7656.RS535, University of Cambridge Library.

12. William Huggins, "Visitors to the Observatory, 1867," Notebook 2; Edward Sabine, "President's Address," Proceedings of the Royal Society 17 (1868):  135-50; 138.

13. See for example, "Suggestions for the New Spectroscope," W. H. M. Christie to G. B. Airy, 24 October 1872, RGO 6.174/3/8/96-103; "Spectroscopic Apparatus &c recommended by Mr. Huggins," William Huggins to G. B. Airy, 23 January 1874, RGO 6.174/3/8/83; W. H. M. Christie to William Huggins, 4 February 1874, RGO 6.174/3/8/84; William Huggins to W. H. M. Christie, 5 February 1874, RGO 6.174/3/8/85; William Huggins to W. H. M. Christie, 20 February 1874, RGO 6.174/3/8/89; William Huggins to W. H. M. Christie, 19 March 1874, RGO 6.174/3/8/91.  Finally, on 20 March 1874, Christie wrote to Huggins, "Your advice has been of so much service to us that we shall be very glad indeed to have the advantage of your examining the spectroscope and making any practical suggestions for which I needn't say, we shall be most grateful."  RGO 6.174/3/8/94, University of Cambridge Library.

14. Title page, Notebook 2.

15. "Visitors to the Observatory," Notebook 2.

16. William Huggins to John F. W. Herschel, 18 May 1866, HS.10.40, Herschel papers, Royal Society Library.

17. John Herschel, "On the Increase of Magnitude in h Argûs," Monthly Notices of the Royal Astronomical Society 4 (1836-1839):  121.  Herschel also submitted papers on the variability of other stars as well, including a Cassiopeiae, a Orionis, h Cygni and others.

18. For a discussion of variable stars from a mid-nineteenth century viewpoint, see Grant, 540-1.  Agnes Clerke also discusses stellar variability in her book A Popular History of Astronomy during the Nineteenth Century, 2nd ed., (Macmillan & Co.:  New York, 1887):  426-34.  For a modern survey of the history of variable star observation, see Helen Sawyer Hogg, "Variable Stars," in Astrophysics and Twentieth-century Astronomy to 1950:  Part A, Owen Gingerich, ed. (Cambridge University Press:  Cambridge, 1984):  73-89.

19. "U Scorpii," Robert Burnham, Burnham's Celestial Handbook (Dover:  New York, 1978) 3:  1689-93.

20. First noted by Edward Pigott in 1795, R Coronae was, most of the time, a star just at the limit of human vision.  Unlike most other variable stars which briefly flare up in brightness, Pigott and subsequent observers claimed that this star occasionally dimmed quite suddenly for periods of a few months, and did so at highly irregular intervals.  In late 1863, the star reportedly dimmed dramatically as it had before, but by 1866, it failed to regain its usual level of luminosity in spite of a brief and slight brightening in mid-1865.

21. Birmingham's discovery of the nova may have been entirely accidental.  In a letter to E. J. Stone, dated 7 July 1866, Birmingham stated only that he was "struck with the appearance of a new star in Corona Borealis" as he walked "home from a friend's house."  He gives no indication that he was according that region of the sky any special attention.  See, J. Birmingham, "The New Variable near h Coronae," Monthly Notices of the Royal Astronomical Society 26 (1866):  310.  The priority claim of Mr. Barker of London, Ontario produced a brief but energetic exchange of letters in the Astronomical Register 4 (1866):  268; 310-1.

22. Huggins cited the contents of Birmingham's note in his Nineteenth Century retrospective article written in 1897.  In this later account, Huggins mistakenly reports that he received the letter on 18 May when it is clear from his notebook entry and his letter to Herschel cited earlier that Birmingham's letter arrived on the 16th.  This is a relatively insignificant error, and may say nothing about the accuracy with which the rest of the excerpt has been transcribed, but, as I shall show in a few later instances, Huggins took liberties in transcribing other things. Thus, we must look with some suspicion on this alleged quote from Birmingham.

23. By 1866, Baxendell had been observing variable stars for nearly twenty years and had recently married the sister of veteran variable star observer Norman Pogson. See, "Joseph Baxendell," Monthly Notices of the Royal Astronomical Society 48 (1888):  157-60.

24. An extract of the letter, dated 10 February 1866, was published in Monthly Notices of the Royal Astronomical Society 26 (1866):  214.

25. See, Rev. Father Secchi to Warren De La Rue, 4 [February or March] 1865, "On the Spectrum of the Nebula of Orion," in Monthly Notices of the Royal Astronomical Society 25 (1865):  153-5 and Astronomical Register 3 (1865):  105-6. [Note:  The date of the letter is unclear as the two sources in which it is printed disagree.]

26. For a summary of the discussion which ensued surrounding the reading of Secchi's letter see, Astronomical Register 4 (1866):  97-8.

27. W. Huggins and W. A. Miller, "Note on the Spectrum of the Variable Star a Orionis, with some Remarks on the Letter of the Rev. Father Secchi," Monthly Notices of the Royal Astronomical Society 26 (1866):  215-7.

28. At the same meeting of the RAS in which Secchi's letter was read (9 March 1866), a paper by Herman Goldschmidt was presented which claimed to have demonstrated that a new star seen in 1827 was identical to one recorded on several occasions in the past making it not so much a "new" star, as a variable of exceptionally long period.  Following the paper's presentation, one individual was prompted to comment that it seemed likely that several novae would turn out to be long-period variables as well.  See Astronomical Register 4 (1866):  97.

29. In the 1860s, variable stars not already assigned a letter of the Greek alphabet designating its brightness relative to other stars in the constellation (a system developed by Bayer in 1603), were named according to a scheme (developed by F. W. A. Argelander in 1844) which uses a roman capital letter in the order in which their variability was discovered beginning with the letter "R" and going through "Z."  See Hogg, "Variable Stars," 73-89.  See also, William Huggins and William Allen Miller, "On the Spectrum of a New Star in Corona Borealis," Proceedings of the Royal Society 15 (1866):  146-9; 146.  William Huggins, "On a New Star," Monthly Notices of the Royal Astronomical Society 26 (1866):  275-77; 277.

30. William Huggins, 16 May 1866, Notebook 2.

31. Huggins and Miller, "On the Spectrum of a New Star in Corona Borealis," Proceedings of the Royal Society 15 (1866):  146-9.  While this paper was submitted on 17 May, and dealt primarily with observations made on the evening of the 16th, notes were added to the text before it was published containing the results of subsequent observations.

32. William Huggins, 17 May 1866, Notebook 2.  To generate a hydrogen spectrum, Huggins induced a spark between platinum wires covered with wet cotton.

33. Charles Pritchard, "On the Telescope, its Modern Form, and the Difficulties of its Construction," Proceedings of the Royal Institution 4 (1866):  641-4.

34. William Huggins, 18 May 1866, Notebook 2.

35. See, "Mr. Huggins, at the President's request....," Astronomical Register 4 (1866):  181.

36. William Huggins, "On a Temporary Outburst of Light in a Star in Corona Borealis," Quarterly Journal of Science 3 (1866):  376-82.

37. This address was soon published as a small book entitled On the Results of Spectrum Analysis Applied to the Heavenly Bodies (W. Ladd:  London, 1866), a book which gained wide circulation and was translated into French and German.

38.Ibid., 26-8.

39. See Charles Pritchard to Sir John F. W. Herschel, 27 March 1867, reprinted in Charles Pritchard:  Memoirs of his Life, compiled by Ada Pritchard (Seeley and Co., Ltd:  London, 1897):  257-8.  "In Good Words of next April I give some account of Frauenhofer's [ sic] Lines and T. Coronae, and at last just venture on the speculation that it may be an old worn-out sun waxed dim -- Faye says with a crust on it; and then a planet and a satellite went crash or scrape into it.  If so, the ocean of the planet might afford the hydrogen and the blue that (as when the wind blows over gas), and the crash of the satellite (oceanless) might have caused the second outburst!"

40. As we shall see in the next chapter, it may be this article which first attracted William Huggins' future wife, Margaret Lindsay Murray, to apply spectroscopic analysis of the light of celestial bodies.

41. William Huggins, 8 October 1866, Notebook 2.

42. Angelo Secchi, "On g Cassiopeiae," Astronomische Nachrichten No. 1612 (23 August 1866); idem., "Communications relative à l'analyse spectrale de la lumière de quelques étoiles," Comptes Rendus 63 (1866):  324; see also Monthly Notices of the Royal Astronomical Society 27 (1867):  135.

43. "Spectrometric Studies," from the Bulletino Meteorologico (30 September 1866) in Astronomical Register 4 (1866):  280-5; 284.

44. William Huggins, 8 October 1866, Notebook 2.

45. William Huggins, 12 October 1866, Notebook 2.

46. In his notebook account of his observation of Wolf and Rayet's stars on 18 November 1866 (Notebook 2), Huggins states, "Looked at three stars with bright lines seen by M.M. Wolf & Rayet.  Saw with great distinctness one very strong bright line in the first two.  Uncertain about other lines.  Spectrum appeared continuous."  In his published account in the Monthly Notices of work done at his observatory for the year, he simply reported, "Mr. Huggins has confirmed the observations of M.M. Wolf and Rayet so far as to the presence of bright lines in the three small stars described by them," [ 28 (1868):  87].

47. The possibility that bright lines might be observed in non-variable stars had important theoretical implications, particularly as Huggins and others began to see the utility of spectroscopic data in formulating evolutionary schemes for stars.  In addition to checking Secchi's reports of bright line spectral signatures in certain red stars, Huggins independently checked other reports of bright lines in stellar spectra. In 1868, for example, he announced his confirmation of Wolf and Rayet's claim to have observed bright lines in three small stars in Cygnus.  See, William Huggins, 18 November 1867, Notebook 2; "Mr. Huggins' Observatory," Monthly Notices of the Royal Astronomical Society 28 (1868):  86-8.


TABLE OF CONTENTS

William Huggins' Early Astronomical Career

  • Chapter 2—

Unlocking the "Unknown Mystery of the True Nature of the Heavenly Bodies"

The Astronomical Agenda:  1830-1870

"A sudden impulse..."

Reception of Spectrum Analysis Applied to the Stars

  • Chapter 3—

Moving in the Inner Circle

    • Part 1—

Cultivating Advantageous Alliances; Opportunism and Eclecticism

Opportunism and Eclecticism (continued)

Achieving "A mark of approval and confidence"

  • Chapter 4—

Margaret Huggins: The myth of the "Able Assistant"

The Solitary Observer

Celestial Photography

Diversity and Controversy: Defining the Boundaries of Acceptable Research

  • Chapter 6—

Solar Observations at Tulse Hill

The Red Flames

The Eclipse Expedition to Oran

Photographing the Corona Without an Eclipse

The Bakerian Lecture