by Dava Sobel
In 1918 part one of the long-awaited revision of the Henry Draper Catalogue by Annie J. Cannon and Edward C. Pickering appeared in print. Pickering personally covered the cost to publish it as volume 91 of the Annals, and described the process of its preparation in his preface. Beyond Miss Cannon’s four years of “unfailing enthusiasm” and “persistent work” in reclassifying the spectra of 222,000 stars, she had also invested two years in writing remarks and otherwise readying the material for printing. At least five assistants at a time, though not always the same five, had aided her throughout. Pickering named “Misses Grace R. Brooks, Alta M. Carpenter, Florence Cushman, Edith F. Gill, Mabel A. Gill, Marian A. Hawes, Hannah S. Locke, Joan C. Mackie, Louisa D. Wells, and Marion A. White” as the ones who had ascertained the positions and magnitudes of every star included, as well as helped proofread the hundreds of pages of tables and text. He stressed the efficiency of the women’s effort and cooperation: “A loss of one minute in the reduction of each estimate would delay the publication of the entire work by the equivalent of the time of one assistant for two years.”
By this point Pickering, who liked to keep count of everything, figured the observatory had satisfied thirty-seven thousand outside requests for spectral classifications. Projecting the frequency with which astronomers would consult the printed authority far into the future, he took pains to choose paper that “should not be affected by time.” Although experts had assured him a rag content of sixty percent would be more than adequate, he opted for eighty instead, despite the added expense. “It is hoped that these volumes”—eight more were to follow the current issue—“will form a lasting tribute to the memory of both Dr. and Mrs. Draper.”
A tipped-in frontispiece illustrated the principal types of spectra, B through M, with their distinguishing features, but both Pickering’s preface and Miss Cannon’s coda apologized that these reproductions portrayed only a fraction of the Fraunhofer lines visible in the original glass negatives.
For the second volume of the catalogue (Annals volume 92), which came out later the same year, the authors chose a studio portrait of Henry Draper as the frontispiece. It depicted the doctor in two-thirds facial view, with an expression serious but not stern, and a few stray locks of hair jutting out by his ear. The same photograph had served as the model for the Henry Draper gold medal awarded by the National Academy of Sciences.
On Christmas Day 1918, Pickering wrote a brief preface for installment number three of the catalogue series. “The Henry Draper Memorial is due to the unfailing devotion of Mrs. Draper to the memory of her husband,” he reflected. “It seems, therefore, very appropriate that her portrait should appear as a Frontispiece to this, the third volume of the greatest work yet undertaken as part of the Henry Draper Memorial.” Mrs. Draper, seen here in profile, looked ready to welcome guests at one of her Academy dinners. She wore a gown with exquisite lacework and her red hair pinned up in tight ringlets.
• • •
WELL BEFORE THE WORLD WAR ENDED, Pickering began agitating for the resumption of international relations among scientists. In August 1918 he had told George Ellery Hale, “No ordinary punishment is adequate for those responsible for barbarities contrary to the laws of nations and humanity, yet we ought not to ignore the work of those who, laboring quietly in their observatories, have done their best to extend our knowledge in these terrible times.” After the Armistice of November 1918, Pickering declared himself eager to write to longtime friends in Germany as soon as mail communication could be restored. “I am anxious to know how far European observatories have suffered,” he said in a letter to Elis Strömgren of the Østervold Observatory in Copenhagen on January 7, 1919, “and what is likely to be their condition when the peace treaties are actually signed.” He resented the sentiments of certain colleagues in the United States and the United Kingdom who talked of excluding scientists of enemy or neutral nations from postwar professional societies. “I believe that many astronomers agree with me,” he told Strömgren, “that we should make every effort for the advancement of our science, regardless of personal or national considerations.”
Later that month, however, Pickering’s own efforts came to an end. His strength suddenly failed him while he was working at the observatory, and he needed to be helped over the few steps home to his residence. The cause of his death, on February 3, was given as pneumonia.
Edward Pickering had been director of the Harvard College Observatory for forty-two years, serving longer than the combined tenures of all his predecessors. Anguish at his loss was widespread.
“I warmly admired his great ability, his originality of view, his power of organization, and his unwearied initiative,” George Ellery Hale wrote to Solon Bailey on February 4. “I also appreciated how much he did, in so many ways, to stimulate research and to help astronomers everywhere. The great development of the observatory under his direction, and its immense contribution to the progress of astronomy, mark an epoch, universally recognized, in the advancement of science.” Hale, who had volunteered as a Harvard assistant while a student at MIT, said he still remembered Pickering’s showing him the original photographs of stellar spectra made by Henry Draper. “What I shall remember with greatest pleasure, however, is his kindly interest in me as an unknown amateur when I first came to the observatory. Many others have enjoyed this experience, for the circle of amateurs he touched and helped was a wide one.”
Bailey, like Hale, had first arrived at the observatory as an amateur volunteer. One of his first duties now, as acting director in the great man’s absence, was to compose Pickering’s obituary for Hale’s Astrophysical Journal. “For men and women he had an equal charm,” Bailey commented after elaborating the milestones of the illustrious life story. “His grace of manner and conversation was the constant wonder of all who knew him intimately. Over all, old and young, wise and witty or ignorant and stupid, who seemed to have any claim upon him, he threw the glamor of his personality.”
Bailey spoke also of the library of glass plates, gathered pole to pole and year to year, as the repository of Pickering’s guiding spirit: “It still exists, its possibilities by no means exhausted, its value in many ways increasing as the years go by. . . . Within this great collection of stellar photographs . . . there still remains for Professor Pickering the possibility of an immortality of scientific labor, more unique and worthy than ordinary fame.”
Miss Cannon, the consummate master of obituary form, sketched the director’s much admired qualities in Popular Astronomy: “He will be missed for his warm-heartedness, always eager to help the young astronomer, whether by securing grants of funds or in the selection of his life work; for his cordiality, the ideal host in welcoming visitors to the Observatory; for his sympathetic, inspiring personality, which, by its very optimism and faith in humanity, made us believe in ourselves and our capabilities.”
Miss Cannon concluded, “His joy in taking part in what he called the greatest problem ever presented to the mind of man, the study of the starry universe, never left him, and, even in his last illness, he spoke of having new ideas about work. . . . He measured the light of the stars and first placed them in an orderly evolutionary sequence. He left, as his legacy to the world, the history of the sky for the last thirty-five years imprinted on the Harvard collection of photographs.”
PART THREE
In the Depths Above
I saw in the stars a chance to observe phenomena beyond terrestrial scope. Nothing seemed impossible in those early days; we were going to understand everything tomorrow.
—Cecilia Payne-Gaposchkin (1900–1979)
Phillips Astronomer, Harvard College Observatory
There are two ways of spreading light: to be the candle or the mirror that reflects it.
—Edith Wharton (1862–1937)
Author of The Age of Innocence and other acclaimed novels
CHAPTER ELEVEN
Shapley’s “Kilo-Girl�
�� Hours
MARY H. VANN, an alumna of Cornell University, devoted her 1917–1918 term as the first Edward C. Pickering Fellow to an analysis of the new stars, or novae, that had shown up on the Harvard glass plates since 1887. Most of the eleven such stars had never been observed visually by anyone, or photographed by any other institution. Now, thanks to the abundance of plates and Miss Leavitt’s completion of the North Polar Sequence, Miss Vann had the necessary tools to assess the novae’s changing magnitudes over time and create a light curve for each one. On June 8, 1918, shortly before she left the observatory to take up war work, a new nova erupted in the constellation Aquila, outshining all but the very brightest stars for several weeks. At magnitude −0.5, Nova Aquilae 1918 proved the brightest such sight since the invention of the telescope, but its photographic study fell to the second Pickering Fellow, Dorothy W. Block, a 1915 graduate of Hunter College in New York City.
Unlike the astronomical fellowship of the Nantucket Maria Mitchell Association, now permanently assigned to Margaret Harwood, the Pickering Fellowship entailed no Nantucket residency rule. The recipient was welcome to visit Miss Harwood on the island during the summer months, if she so chose, but the real reward consisted of research funding at Harvard through a typical fall-to-spring academic year. Miss Block devoted her allotted time in 1918–1919 to measuring the changing light of variable stars, several asteroids, and of course the Great New Star in Aquila. In the spring, she also learned to photograph the stars, so that she often stood in for the regular assistant during the first part of the night. This experience helped her secure a job offer from the Yerkes Observatory in Williams Bay, Wisconsin, where she was about to become the first woman ever allowed to take photographs through its 40-inch telescope, the world’s largest refractor.
As Miss Block prepared to leave Cambridge, Henry Draper’s niece Antonia Maury petitioned to become the next Pickering Fellow. At fifty-three, the experienced Miss Maury was roughly twice the age of either Miss Vann or Miss Block. However, she met the crucial requirement of holding a college degree, Vassar class of 1887, and had studied astronomy under the beloved Maria Mitchell.
“With regard to Miss Maury,” Lydia Hinchman of the Maria Mitchell Association asked Annie Cannon in a letter of April 8, 1919, “I have heard she is peculiar, is that true? I also have heard she has a brilliant mind. I scarcely feel competent to give an opinion without seeing her, but it is for one year and if you feel so disposed, you might try it.” Miss Cannon chaired the selection committee, but Mrs. Hinchman was entitled—and accustomed—to offer advice: “If her peculiarities are not to the front I would try it.”
Miss Maury had resumed her on-again, off-again association with the Harvard Observatory in August 1918, by attending the American Astronomical Society meeting held there. It was her first meeting as an elected member of the organization. Pickering, who was then the society’s president, had invited Miss Maury to stay on in Cambridge as a voluntary associate researcher. Thus, with no prospect of salary, she rekindled her first love—the very close double stars known as spectroscopic binaries. Months later, following the director’s death, Professor Bailey encouraged Miss Maury to take a paid position as assistant to John Stanley Plaskett at a brand-new observatory in Victoria, British Columbia, but, at this stage of her life, she could not readily relocate so far from anywhere she had ever called home.
Miss Cannon and Miss Maury, close contemporaries, had overlapped in their careers at Harvard long enough to judge each other’s character and quirks. Miss Cannon deemed her colleague entirely deserving of the fellowship opportunity, and Miss Maury gratefully accepted the $500 stipend.
• • •
THE FIRST TWO PARTS of the revised and expanded Henry Draper Catalogue, published as Annals volumes 91 and 92, made Harlow Shapley impatient for the third. “Can you predict when 93 will be distributed?” he inquired of Miss Cannon from his post at Mount Wilson on May 8, 1919. “It happens to be the most important of all to me. I am using your results to check my work on cluster structure, and the stars of the southern Milky Way . . . play an important role.” By “cluster structure” Shapley referred not to the distant globular clusters ringing the periphery of the Milky Way, but to what he termed the local cluster, meaning stars in the vicinity of the Sun—stars close enough to be described in the catalogue according to their position, magnitude, and spectrum. Parts one and two of Miss Cannon’s magnum opus had covered several longitudinal swaths of the 360-degree sky panorama, from zero degrees, or the “zero hour” in astronomical parlance, to ninety degrees, the sixth hour. Shapley now needed the seventh and succeeding hours, yet to be revealed in the next installments, to continue his study of the organization of the solar neighborhood.
Volume 93, Miss Cannon assured him, had already been set in type, but the bookbinders had gone on strike, and she could not say how long publication might be delayed by the settling of their grievances. Meanwhile she satisfied Shapley by mailing him the unbound signatures. The observatory, even in Pickering’s absence, was continuing to operate by his guiding principle: first you gather all the information, then you give it away to those who crave it.
“My very best thanks for your kindness in sending me proof-sheets of the third volume of the Henry Draper Catalogue,” Shapley wrote back. “I have been through it all and have obtained just the information I thought would be there relative to the form and extent of the local cluster.” Shapley wanted more than one way to measure distances across the galaxy. The Cepheids had demonstrated their special powers as distance indicators, but Miss Leavitt’s stars were few in number. Shapley thought the more numerous, luminous stars belonging to spectral class B could also provide distance clues. B-type stars were generously scattered through the Milky Way, and their positions and magnitudes already well established through thousands of reliable measures, all collated in the Harvard catalogues. In general, the B stars shone some two hundred times brighter than the Sun. From Mount Wilson, Shapley could make out the spectra of B stars among distant clusters via the 60- and 100-inch telescopes. By the relative faintness of the remoter B’s, he was able to estimate their distance, and thus employ them as alternate mileposts. Shapley thought the giant red stars could also be engaged as measuring aids, since they, too, populated both the globular clusters and the Milky Way.
Many other researchers, pursuing other studies, echoed Shapley’s clamoring for the remainder of the Henry Draper Catalogue. The later volumes, however, faced a problem more serious than labor disputes, namely lack of funds. “The prompt publication of all this material is necessary in order to complete the great life work of the late Director,” Solon Bailey stressed in his first report as acting director. He projected the cost at $15,000 beyond the income of the observatory. While seeking funding, he honored and tallied the urgent requests from individual astronomers for particular spectra. Hundreds of such queries arrived every month.
Edward Pickering had told President Lowell in 1910 that he considered Professor Bailey the only member of his staff capable of taking over the observatory as acting or permanent director. After Pickering’s death in 1919, Bailey’s assumption of responsibility had proceeded seamlessly, but the Harvard administration made no move to confirm him as the fifth director. George R. Agassiz, a member of the Visiting Committee and patron of the observatory, counseled Lowell to go for “new blood and real distinction.” Not even Bailey considered himself, at age sixty-five, the right person to lead the observatory into the future. He pictured a younger man taking charge, someone like Harlow Shapley of Mount Wilson—or better yet Shapley’s mentor, Henry Norris Russell of Princeton, only forty-two years old and widely regarded as a brilliant thinker. On learning of his eligibility, the cautious Russell raised an eyebrow. He half-suspected that Abbott Lowell would have appointed his own “distinguished brother,” the Mars expert, as director, if only Percival Lowell were still alive. The founder of the Lowell Observatory, however, had passed away at Flagstaff in 1
916. Pickering’s brother, William, on the other hand, though not in the running for the directorship, remained at large in Mandeville. Should Russell accept Harvard’s overtures, he would inherit William along with the other staff members, and that thought gave him pause. William seemed obsessed with Martian canals, claimed to have detected water on the Moon, and was known to be calculating the whereabouts of a planet beyond Neptune.
Neither Miss Cannon nor Miss Leavitt, being female and fifty-plus, was eligible for the directorship. Nor did either wish the position for herself. Miss Leavitt, never physically strong, had been forced to leave the big house on Garden Street when it was sold after her uncle Erasmus Leavitt died in 1916. She had moved into a rooming house, but when her widowed mother came back East, the two of them took an apartment together on Linnaean Street, close to the observatory. Miss Cannon, still living happily with her older half sister, Ella Cannon Marshall, continued to accrue honors at home and abroad. The University of Delaware awarded her a doctor of science degree in 1918, claiming her as a distinguished native daughter of the “Diamond State.” In 1919 her English friend Herbert Hall Turner, the Savilian Professor of Astronomy at Oxford, sought to raise her standing in the Royal Astronomical Society. “The other day,” Turner wrote her on May 13, “I proposed your name as an Associate of the R.A.S.—on the same footing as men. I hoped you would regard it as a new recognition: & that by thus transferring our one ‘Honorary Member’ we should remove the last remaining trace of the previous disability of women. But the Council disagreed with me & thought you would prefer your present ‘lonely isolation’ as a greater honor.”
