The Glass Universe

by Dava Sobel

  After explaining the purpose of the Florida stay as a way to “woo back our little daughter to robust health,” Mrs. Carnegie closed with the hope “that we may some day have the great pleasure of welcoming you, not only to our New York home, but better than that give you a ‘Hieland’ welcome to our home in bonnie Scotland.” Mrs. Carnegie had been born in the Gramercy Park neighborhood of New York City, but regarded herself Scottish by association with Andrew, who had come from Dunfermline.

  Margaret Carnegie, the couple’s only child, was a precocious nine-year-old with a sprained ankle. Mrs. Fleming felt a bond with “Miss Margaret” that inspired her to send frequent tokens she thought the child might enjoy, including pictures of stars, a book that described the laying of transoceanic cables, and even a specimen of cable. “It gave me great pleasure to learn from your letter of February 16,” she told Mrs. Carnegie, “that Miss Margaret was gaining in health and was enjoying herself in the sunshine and flowers of beautiful Florida. Also, that the valentines afforded her some amusement. On the evening of February 13 my brother and I spent the whole evening doing up and addressing Valentines for schoolmates and friends of his little fellows. Outside my scientific work, my next joy in life lies in giving pleasure to others.”

  Over the ensuing months Mrs. Fleming continued to unbosom herself to Mrs. Carnegie: “Of my own two boys, only one lived to grow up. He is 26 years of age and is one of President Pritchett’s boys, having graduated from the Massachusetts Institute of Technology in 1901. He is a mining engineer, especially interested in copper, and has been with the Phelps Dodge Co. at their Copper Queen property in Douglas, Arizona, during the last year and a half. . . . He is a good boy and makes true friends wherever he goes, but being a boy, and in such a profession, he is away from me almost all the time. I am not in danger of being lonely, however, as I have my mother to look after, and she keeps us stirring.” Mrs. Fleming’s youngest brother, a recent widower, and his two sons, ages eight and twelve, also lived with her.

  A newspaper announcement of the Carnegies’ travel plans alerted Mrs. Fleming to the fact that their spring stay in New York would be brief. The news seemed to rule out the possibility of their visiting Cambridge to see the observatory, in which case, she said, she would “wait patiently for the fall,” in the hope of welcoming them then.

  Mrs. Fleming received perhaps the most pleasant shock of her life on May 11, 1906, just four days before her forty-ninth birthday, when the Royal Astronomical Society elected her to honorary membership. The society, formed in 1820, had recognized the role of women astronomers early in its history, by awarding a gold medal to Caroline Herschel in 1828 for her several discoveries of comets. No woman could be admitted as a full fellow, of course, but over the years the society had made honorary members of a few female British subjects, including, most recently in 1903, Lady Margaret Huggins, the wife of Sir William Huggins, Henry Draper’s old rival. Mrs. Fleming became the first American woman to earn the distinction, or rather the first woman doing astronomical work in America. She was still a Scotswoman through and through, with the brogue to prove it. But, after her long and productive residency in the United States, she thought it might be high time she applied for American citizenship.

  • • •

  PICKERING HAD LIKENED THE PLATE COLLECTION to a library lacking readers. In 1906 the observatory’s Visiting Committee compared it to a gold mine minus a refinery: “Like a mining company which has put out of the ground a vast quantity of precious ore, but lacks the means for reducing the ore and preparing the metal for market, the Observatory possesses a great store of knowledge in the rough, but wants the means for working this knowledge into useful shape for the benefit of the world.”

  Solon Bailey, still in Cambridge and elated by the burgeoning population of variable stars, urged Pickering in 1906 to unite the astronomers of the world in a new cooperation. Miss Leavitt had worked alone in a few isolated regions of space. Surely her phenomenal findings justified canvassing photographs of “the whole sky, in order to determine the number and distribution of all variable stars, to the faintest magnitudes possible.” Without such a concerted approach, Bailey feared, any search would be plagued by needless duplication and wasted effort.

  Pickering concurred. He issued another circular, inviting observatories everywhere to equip themselves with the proper telescopes and cameras “to study the distribution of the variable stars, and learn what part they play in the construction of the stellar universe.”

  Pickering estimated the sky held as many as fifty million stars brighter than sixteenth magnitude. He wanted to test the constancy of every last one of them. “The comparison of such a vast number of stars on several plates is indeed so great an undertaking, that at first it seems impossible,” he allowed in his announcement. But the outcome he foresaw “would be a worthy achievement for the present generation of observers.”

  Given Harvard’s position at the variable star vanguard, Pickering did not wait for others to heed his call. He pushed forward with his own research assistants and limited resources. He asked Miss Cannon and Miss Evelyn Leland to master Miss Leavitt’s method. Then he divided the heavens, like Gaul, into three parts, and apportioned one to each of them.

  • • •

  LIZZIE PICKERING HAD FALLEN and broken her ankle in her bedroom in February 1903, and from that point on her health had gradually deteriorated. The break incapacitated her for more than six months; when she could walk again, she did not feel up to resuming her former activities. She did not even attend the party at Anna Draper’s house in New York on December 29, 1905, to celebrate the twentieth anniversary of the Henry Draper Memorial. Mrs. Draper laid her friend’s absence to a merely temporary illness, but upon visiting the Pickerings in March 1906, she could see the seriousness of the situation well enough. Afterward she wrote Pickering to say she hoped his wife would soon be better. What else could one hope?

  In May, when Mrs. Draper desired yet another tour of progress at the observatory, she stayed at the Brunswick in Copley Square, and made plain she did not expect to be entertained. “Do not take the trouble to have luncheon for me, for I can take an early lunch at the hotel.” Mrs. Draper also wrote directly to Mrs. Pickering, continuing their cordial correspondence as though it might carry on indefinitely. So many times over the years their thoughts had turned toward each other at the same moment, with the curious result that their letters often crossed in the mail.

  Mrs. Pickering’s surgery in June 1906 succeeded in easing her pain, but neither she nor her husband believed it would extend her life. They shaped their plans accordingly.

  All that summer the director kept up his work at the observatory, just a few steps away from Mrs. Pickering’s sickroom in the residence. In mid-August, when he learned that the English astronomers John and Mary Orr Evershed were en route to Cambridge, he cabled their ship to welcome them as graciously as possible under the circumstances. “The very serious illness of Mrs. Pickering may prevent our entertaining you at our house as, otherwise, we should wish to do.” Mrs. Pickering died on August 29, and was buried in Mount Auburn Cemetery near the graves of her parents, Jared and Mary Sparks.

  “My future interests in life are likely to be somewhat restricted, and my years of usefulness cannot be very numerous,” Pickering predicted to Edwin P. Seaver of the Visiting Committee two weeks later. “The needs of the Observatory are so pressing, and so much could be accomplished by an immediate expenditure, that I am inclined to give it a large part of my savings.” In September he paid the first installment of a promised $25,000 to be disbursed over the next three months, challenging other donors to contribute its equivalent.

  Along with the many expressions of sympathy, Pickering received an appeal that autumn from Elizabeth Lidstone Bond, a granddaughter of the observatory’s first director. Miss Bond apologized for intruding at such a time, but she and her sister required his advice on a personal matter. “You know, of
course, of my Aunt Selina’s poverty,” she wrote on October 13. He did know of it, yes. Sudden poverty had driven Selina Cranch Bond to beg Pickering, almost the moment he took over the observatory in 1877, for employment. Although her father, William Cranch Bond, had provided for his heirs through the family’s profitable watch, clock, and chronometer manufactory in Boston, a scurrilous trustee later cheated the descendants out of their inheritance. Pickering was still sending Miss Bond occasional computing work that she, now seventy-five, could do at home in Rockland, Maine.

  Elizabeth and her sister, Catherine, the daughters of George Phillips Bond, had been impoverished by the same blow dealt their aunt Selina. They, too, had worked briefly for Pickering, as copyists and translators, before establishing themselves as schoolteachers. Elizabeth thought her aunt Selina, “the aged daughter of an eminent man like my grandfather, as poor as she is,” might justly claim assistance from a particular Harvard pension fund. The sisters hoped Pickering could direct them to a member of the pension-fund committee, and counsel them about how to proceed, given “your position in the observatory, and the unfailing kindness and consideration you have always shown us.”

  Elizabeth conceded the many difficulties likely involved, not least her aunt’s unwillingness to accept money from anyone. “She has made her independence her religion.”

  Pickering assured the anxious nieces of his aid, and wrote the same day to President Eliot to inquire about the pension fund. On learning that it could support former faculty members only, Pickering devised an annuity tailored to the situation. He would put $1,000 of his own, to be matched by sums from the Bond sisters and their cousins, into the Harvard Corporation for investment. Starting immediately, Selina Bond would receive $500 a year (nearly double her present salary as a part-time, at-home computer) for as long as she lived. In addition, she would be relieved of all responsibilities and granted the title of assistant emerita in the observatory, “in consideration of the distinguished and long continued service to astronomy of her father, her brother, and herself.”

  “Perhaps you can suggest some better arrangement,” Pickering wrote to the Bond sisters. “In any case, she had better not know where the money comes from, but receive her first notification from the College Treasurer.”

  Elizabeth and Catherine Bond embraced the plan, except that they refused to let the director pay even so much as one dollar toward its execution. “May I add this moral?” Catherine asked Pickering in mid-November, when all the arrangements had been settled and her aunt surprised but gratified by the recognition conferred. “In your loneliness and sorrow it must be some consolation to you that in these past weeks you have been lifting such a weight of anxiety from the sister and daughters of your predecessor. So often my sister and I have been glad that you were our father’s successor, but never more so than now!”

  CHAPTER EIGHT

  Lingua Franca

  THROUGHOUT 1906, the triumvirate of variable star hunters—the Misses Cannon, Leavitt, and Leland—combed piecemeal through Harvard’s photographic maps of the sky. Each woman’s third of the heavens encompassed a score of subdivisions to be searched individually and repeatedly. Henrietta Leavitt, whether because of her greater previous experience or the luck of the draw in the sectors assigned to her, took an early lead. She found 93 new variables within months of the hunt’s start in 1906, trailed by Annie Cannon with 31, and Evelyn Leland, 8. Competition for the most discoveries played no part in their pursuit, but Pickering tallied and reported the women’s sums. Given the overall quest to learn the distribution of all types of stars in the universe, the absence of variables from a particular region provoked almost as much interest as a strong presence.

  Pickering might have trisected the sky by giving Miss Cannon the north pole, Miss Leavitt the tropics, and Miss Leland the far south, where she was already well acclimated thanks to years of helping Professor Bailey sift the content of his star clusters. Instead of a gross division by celestial latitude, however, the director parceled out the fifty-five parts of Harvard’s “map of the sky” as though dealing a hand of rummy. Thus Miss Cannon received section numbers 1, 4, 7, 10, and so on; Miss Leland numbers 2, 5, 8, 11, etc.; and Miss Leavitt the rest.

  For each stellar region, each lady gathered plates in quintuplicate—four negatives, forming a time-lapse series, plus a positive print (white stars on dark background) from a fifth date, to serve as a basis for comparison. One by one, as Miss Leavitt had done in her exploration of the Orion Nebula, each negative was laid atop its corresponding print. Stars of constant brightness neutralized the differences between their positive and negative images. Variables showed their colors (in black and white) to the practiced eye.

  The women marked all suspects for further investigation. Some of these panned out as truly new finds, others as familiar faces from previous dragnets. With more time or more womanpower, Pickering might have allotted more than five plates per area, but the efficient protocol made the most sense under current constraints. It even allowed him to approximate how many variables escaped detection. If, say, Miss Leavitt located ten in one section, nine of which proved to be new—never claimed by another observatory or captured in an earlier Harvard search—then many more undiscovered variables likely resided nearby. If, however, among ten identified, nine turned out to be already known, then very few others still lurked in that zone.

  “Found two new variables,” Miss Cannon noted in her diary on Saturday, February 23, 1907. “Went to the club. Very cold.” Her club, the women’s College Club of Boston, often drew her out for dinner and entertainment. The extreme cold persisted through Sunday. “Did not go to church.”

  After quitting the house on Upland Road to make room for Mrs. Fleming’s mother, brother, and two nephews, Miss Cannon invited her widowed older half sister in Delaware, Ella Cannon Marshall, to come live with her in Cambridge. They spent almost every free evening and Sunday together, attending concerts and lectures, shopping, dining with friends, “pouring” at ladies’ teas. Miss Cannon’s Acousticon carbon hearing aid enabled her to enjoy all these things. Sometimes she brought Miss Leland or another coworker home from the observatory to lunch with “Sissie.”

  As Miss Cannon searched the deep space of the map plates for new variables, she continued her telescope observations and augmented her index card collection. Having twice updated her “Provisional Catalogue of Variable Stars” to append the new crops of 1903 and 1904, she hardly expected her “Second Catalogue of Variable Stars,” published in 1907, to be her final word on the subject. Miss Cannon was a census taker in the midst of a population explosion. The Second Catalogue, though comprehensive, concentrated on the variable stars of long period. It did not include the multitude of short-period variables Miss Leavitt had uncovered in the Magellanic Clouds. Those required a separate treatment, currently nearing completion by Miss Leavitt herself.

  “It may be asked,” Solon Bailey wrote in an article for Popular Science Monthly, “why it is necessary, or even desirable, to go on indefinitely with the discovery of new variables.” Aside from “the value of adding any new fact about the universe to the sum of human knowledge,” he offered an astronomer’s version of the mountaineer’s “Because it’s there.” Only after a great number of variables had been discovered, he said, and their changeable natures closely observed, could the inquiry into the causes of variability commence.

  As the search for new variables entered its productive second year, Pickering continued to press for physical plant improvements that would give the books and pamphlets of the library, still housed in the old wooden observatory building, the same fireproof protection now guaranteed to the glass plates. Recent efforts by the Visiting Committee had failed to raise sufficient funds. On March 4, 1907, as though to demonstrate the danger, fire broke out in Pickering’s half-empty house. The flames threatened to engulf the director’s residence and leap to the adjacent east wing of the observatory. Fortunately, the members o
f the observatory brigade, their skills sharpened through years of surprise practice drills, heeded the alarm signal and doused the outburst even before the municipal firefighters arrived.

  • • •

  MINA FLEMING SPOTTED nineteen new variables in 1907. She identified them the same way she always had, by the vagaries of their spectra, as opposed to hunting for them by superposing chart plates. Only later, in the wake of discovery, did she turn to the chart plates to verify her finds. Catching a star in different guises at different times—brighter here, fainter there—clinched its identity as a variable. Following the precise course of its changes over time, however, sometimes required ten or more nearby steady lights to bear witness. Ideally the brightest of these neighbors would shine brighter than the variable at maximum, the faintest one fainter than at minimum, and the differences between the intermediates would not exceed half a magnitude. In 1907 Mrs. Fleming published her modus operandi for choosing and evaluating such sequences of stellar standards. “A Photographic Study of Variable Stars” gave positions and magnitudes for the more than three thousand stars she had corralled to track the two-hundred-plus variables she discovered.

  “Many astronomers are deservedly proud to have discovered one variable, and content to leave the arrangements for its observation to others,” commented Herbert Hall Turner, Mrs. Fleming’s transatlantic colleague in the Royal Astronomical Society, in reaction to this work; “the discovery of 222, and the care for their future on this scale, is an achievement bordering on the marvellous.”