by Dava Sobel
Pickering dictated the all-water route, despite its added expense, to avoid the overland shortcut across the Isthmus of Panama. The fewer changes of conveyance through inexperienced hands, the better, he reasoned. Neither Pickering nor Gerrish ever imagined how the steamer would pitch about in Mollendo’s harbor, even in the best of weather, or how the waves would toss the little launch that ferried the Bruce piecemeal from ship to shore. The captain laughed as he recounted the extreme care exercised at New York, and Bailey shared the joke with Pickering. “It does look rather risky,” he wrote of the Bruce’s off-loading, “to see the heavy pieces roll up and down over the heads of the boatmen.” The process took a full day but met with no mishap. After reaching Arequipa by train, the telescope ascended the last leg of its journey in an oxcart, along the winding trail to the mountain lookout.
Bailey built a shelter for the Bruce with a dome of canvas-covered wood and a pier of local stone set in mortar as its steady base. By the end of May, after many tests of his perseverance and skill, he achieved images of a quality that pleased him. Just when he thought the instrument’s trials were over, the Bruce took an unexpected jolt that almost toppled it.
“Yesterday we had the strongest earthquake which I have ever experienced,” Bailey wrote to Pickering on June 15, 1896. “It came at 10:05 A.M. I could distinctly see the ground move, something which I never saw before. I was in the laboratory. I rushed into the Bruce building which was near to see the effect. The whole mass of the castings etc swayed visibly and the tube shook violently.” Bailey was pleased to report, however, that all the station’s telescopes emerged from the shaking unscathed.
CHAPTER FIVE
Bailey’s Pictures from Peru
EDWARD PICKERING HAD COME TO VIEW Solon Bailey as the heir apparent to the Harvard throne. “You are more familiar with the work of the Observatory in general than anyone else,” the director assured Bailey soon after he resumed stewardship of the Arequipa station, “and as you have the necessary executive ability I want to make your position one of increasing responsibility.” Pickering was not yet fifty, and not looking to retire, but he foresaw the possibility of a sabbatical year for himself, or other protracted absences. He hoped that Bailey, after finishing his current five-year term in Peru, would “undertake more and more of the executive work” at Cambridge, and assume “a large part of the general management of the Institution.” But such forecasting was strictly between the two of them, and premature to boot. Pickering could still rely on loyal, amiable Professor Arthur Searle, ten years his senior, to stand in for him whenever necessary.
Searle had first served as acting director after Joseph Winlock’s death in 1875, and ran the observatory until Pickering took it over eighteen months later. He had been a classics scholar while a Harvard student, then a Colorado sheep farmer, an English teacher, a clerk in a Boston broker’s office, a tutor, and a computer for the U.S. Sanitary Commission. When his astronomer brother, George Mary Searle, left the Harvard Observatory in 1869 to take holy orders as a Catholic priest, Arthur took the vacant place at the telescope. He expected this employment to be as temporary as any of his previous positions, but instead he settled in. A methodical and reliable observer, Searle became adept at photometry, especially as it applied to planetary satellites, asteroids, and comets. He also computed the orbits of these objects and recorded all the observatory’s meteorology data. In 1887 he was named Phillips Professor of Astronomy, and taught classes at the nearby Society for the Collegiate Instruction of Women, which became Radcliffe College in 1894.
Although Pickering viewed the observatory as strictly a research facility, he was himself a gifted educator. He had allowed a few determined female students into his MIT physics classes, and instituted the women’s astronomy courses early in his tenure at Harvard. By now he felt justly proud of the several alumnae who held “positions of the first importance” in their fields. They included Mary Emma Byrd, director of the Smith College Observatory, and Sarah Frances Whiting, professor of physics and director of the observatory at Wellesley College.
Qualified Radcliffe astronomy students occasionally landed unpaid assistantships at the Harvard Observatory. In 1895 Searle and Pickering selected Henrietta Swan Leavitt for this honor, and Annie Jump Cannon a short while later. These two ladies displayed maturity well beyond that of the typical matriculant. They had both completed college studies, traveled abroad, and done a bit of teaching before assuming their duties on Observatory Hill, where they met each other for the first time. By an odd, unfortunate coincidence, Miss Leavitt was suffering the gradual loss of her hearing during this period, and Miss Cannon, having survived a severe case of scarlet fever while at Wellesley, was already quite deaf.
Pickering put Miss Leavitt to work on a new project in photometry. His own ongoing work in this field entailed nightly observations of stellar brightness with telescopes and photometers, but she was to assess magnitudes from the glass photographs. He gave her several years’ worth of plates taken at Cambridge with the 8-inch Bache and 11-inch Draper telescopes, centered on the northernmost stars. Pickering had long relied on the polestar alone as his touchstone, bringing Polaris into the proximity of other stars via mirrors and prisms. Miss Leavitt needed to identify numerous new benchmarks among stars fixed in place on glass plates, and also compare them over time with sixteen long-period variables in the polar region. Later, the visual and the photographic judgments could be cross-checked, calculated, and rectified to achieve a strict new standard of consistency.
Seated at her light lectern, Miss Leavitt chose one variable as a starting point and then proceeded from star to star, judging each one’s magnitude, jotting the brightness number right on the glass plate. In the observatory record books she always used pencil, as protocol required, and changed a ledger entry, if necessary, by putting a line through it and setting her corrected value alongside the original, because erasures were forbidden on those pages. But different rules governed the plates. The non-emulsion side of the glass offered a smooth writing surface, where the colors of India ink stood out against the black-on-white images of star fields, and where errors could be wiped away with a handkerchief. When Miss Leavitt reached the end of one stellar pathway, she picked up another, and marked a new trail of stars. Streams of her colorful numbers emanated from the variables like small bursts of fireworks.
It seemed as though each comparison star struck its own particular note in the chorus of light, while some of the variables covered a wide range of several octaves. Miss Leavitt could still think in musical terms, even as the sound of music faded from her perception. She continued every Sunday at church to sing the hymns that had filled her childhood, first in Lancaster, Massachusetts, where she was born on the Fourth of July, 1868; and later in Cleveland, where the family moved when her father, the Reverend Doctor George Roswell Leavitt, became pastor of that city’s Plymouth Congregational Church. In Ohio, she spent her seventeenth year enrolled at the Oberlin Conservatory of Music, before the onset of her hearing problems diverted her course. After conservatory, as a student of liberal arts at coeducational Oberlin College, and all through her four years of women’s college in Cambridge, she excelled at mathematics, from algebra to geometry to calculus.
Pickering found Miss Leavitt to be of an extremely quiet and retiring nature, absorbed in her work to an unusual degree. Nevertheless he asked her, in February 1896, to introduce the newcomer, Miss Cannon, to the variable stars near the pole. Miss Cannon would also be examining them—not during the daytime on photographs, but nightly by telescope, as the first female assistant ever commissioned to do so. The thirty-two-year-old Miss Cannon owed this privilege to her educational lineage: At Wellesley, she had studied physics with Pickering’s MIT protégée Sarah Frances Whiting, in a program of hands-on laboratory instruction modeled on the methods he innovated. Miss Cannon had also taken Professor Whiting’s astronomy course, which taught her how to handle Wellesley’s 4-inch Browning te
lescope and kept her abreast of activities at the Harvard College Observatory. When the Great Comet of 1882 arrived like a white-winged bird in the autumn of Miss Cannon’s junior year, Miss Whiting supervised observations of its flight over a period of months. For nearly a week the object flared brightly enough to catch the naked eye, even in daylight, but only the telescope could disclose how the comet nucleus broke into pieces after its close brush with the Sun.
Miss Cannon might have followed a quicker trajectory from Wellesley to Harvard, but the lingering effects of scarlet fever grounded her at home in Dover, Delaware. After graduation she took up photography, tutored small groups of students in arithmetic and American history, and made the rafters “ring,” as she put it, playing the organ for Sunday school at the Methodist church. A pleasant decade passed in this fashion, until her mother’s death plunged her into despair. “Am still here in my little room, surrounded by my memories,” she wrote in her diary on March 4, 1894, nearly three months after the funeral of Mary Elizabeth Jump Cannon. “My mother is ever before me. I can see how people lose their minds, for I believe I shall if I am not aroused by something. . . . She was mine and always will be, my most precious mother. Twelve weeks ago tonight, she was downstairs in the spare room and was more worried about my taking a nap on my couch without covering than about herself. She said she knew I was going to be sick for I looked so, and here I am after twelve weeks of agony such as I shall never have to pass through again, here I am well, my constitution will carry me through many weary years, yet may I be led into a useful, busy life. I am not afraid of work. I long for it. What can it be?”
Just as Mrs. Draper had taken solace in founding the memorial project at Harvard after the loss of her husband, so Miss Cannon found a way through her grief by participating in that project. She returned to Wellesley in 1894 as assistant to Miss Whiting, who smoothed her transition to Searle’s “Practical Research” class at Radcliffe and a perch in the observatory.
“Soon it will be ’97. And three years have passed,” Miss Cannon noted at 11:15 p.m. on December 31, 1896, picking up her diary again after a long hiatus. “Two busy years at Wellesley and this one at the Harvard Observatory. The busy life I so longed for has been opened up to me. Friends have come to me from the great world and my heart, my life are now the study of astronomy. They little know what it means to me, how it was the only thread holding my reason, almost my life. . . . I no longer look forward with dread. The days have no terror. I long for my mother just the same, but I feel that I have the patience to run my race, to do the work set before me, and am able to find contentment in my surroundings. I could not help it, thrown as I am with such kind people.”
Her colleague Miss Leavitt had taken advantage of a travel opportunity and left the observatory, at least temporarily, but Miss Cannon still counted eighteen fellow female and twenty-one male associates in her new professional family. At night, when weather permitted, she did what had been considered man’s work: she used the 6-inch telescope in the observatory’s west wing to check on the variables assigned to her, noting the date and hour of each magnitude appraisal she made. Over time, such isolated glimpses would add up to a star’s full cycle of variation, or “light curve,” from maximum to minimum and back to maximum brightness. The curve, in turn, could suggest the type of variation—and perhaps hint at the cause as well. Whenever Miss Cannon felt unable even to estimate a magnitude, she recorded the reason, such as c for cloudy or m if bright moonlight impeded her task.
Daylight hours found her at a light lectern alongside the women in the computing room, examining photographic plates from Arequipa. Miss Cannon’s allotted niche in the Henry Draper Memorial concerned the spectra of the brightest southern stars. The director wanted her to create a southern counterpart to Miss Maury’s classification of the bright stars of the north. The 13-inch Boyden telescope in Peru provided Miss Cannon with the same kind of widely dispersed, highly detailed spectra that the 11-inch Draper telescope had produced for Miss Maury. She could see and appreciate, in the forests of several hundred dark and bright lines, the patterns that had led Miss Maury to develop her complex but coherent system. And yet, Mrs. Fleming’s hydrogen-line alphabet also evinced logic, insight, and internal consistency. One approach focused on the overall pattern of spectral lines; the other emphasized the thickness or thinness of individual lines. Each arranged the stars in a different order. Miss Cannon stirred the two approaches in her mind as she parsed the starlight of the nether hemisphere.
• • •
WHEN CATHERINE BRUCE SAW the evidence from Peru of her telescope’s prowess, she thanked Pickering “a thousand times— no, many thousand times, for each star on those truly extraordinary plates.” She had not seen the actual glass plates, but rather photographic prints that Pickering made from them, as gifts to her. They portrayed Solon Bailey’s bountiful stellar clusters, captured by the giant telescope’s all-seeing eye. Miss Bruce pronounced them “most wonderful productions.” It tickled her, she said, to be for once in the position of recipient, with Professor Pickering as the donor. Meanwhile her own donor activity continued unabated. Requests reached her from astronomers everywhere, and she responded as Pickering advised. To Max Wolf of Heidelberg, the man who had made the first discovery of an asteroid by photography—and named that body Brucia in her honor—she gave $10,000 for a new telescope. As a charter subscriber to George Ellery Hale’s “magazine,” the Astrophysical Journal, Miss Bruce provided the $1,000 required to set the struggling publishing venture on firm financial ground.
In 1897 Pickering approached Miss Bruce on behalf of the young Astronomical Society of the Pacific, entreating her to endow a gold medal as special recognition for lifelong achievement by an individual researcher. In agreeing to establish such an award fund, Miss Bruce stipulated that her medal, like her grants, should go only to the truly deserving, irrespective of nationality. She also thought it would be a grand thing to see the medal bestowed someday on a woman, and added that possibility to the eligibility criteria: “citizens of any country, persons of either sex.” As for the rest, she wished Pickering would “arrange the whole affair.” She was past the age of eighty now, tired, and often ill. She relied more and more on her sister to keep up her astronomy correspondence.
Pickering, along with two other directors of U.S. observatories and three from Europe, submitted nominations for the first Bruce medalist. The astronomical society’s board of directors settled easily on the foremost American astronomer, the already much-decorated dean of celestial mechanics, Simon Newcomb of the U.S. Nautical Almanac Office, whom they considered a philosopher as well as an astronomer and a mathematician. Newcomb had supervised recalculation and tabulation of orbital elements for all the planets, and also improved the efficacy of several astronomical formulas by arriving at new values for fundamental constants, which were adopted by institutions the world over. Miss Bruce, who traced her active support of astronomical research to Newcomb’s 1888 article in the Sidereal Messenger, approved the choice. Newcomb had changed his view of future prospects in astronomy. Now that her grants supported two of his computing projects, he called on her whenever his travels took him to New York. “I like Newcomb decidedly,” Miss Bruce confided to Pickering, “but I believe I like all the astronomers whom I know.” She had become a magnet for them. Pickering remained her special favorite, however, and his Arequipa telescope her most generous gift.
Within the Bruce telescope’s first few months of operation in Peru, it produced photographic charts of the entire southern sky. These images at once supplemented and augmented the existing southern star catalogues. The Uranometria Argentina of 1879, for example, listed the position and brightness of 7,756 stars to the limit of seventh magnitude. A single Bruce exposure of three hours’ duration collected the light of as many as four hundred thousand stars, some as faint as fifteenth magnitude. Pickering offered “glass copies of our negatives” to all interested astronomers, to be used as sourc
e material for any number of important investigations.
The Bruce telescope saw, as no predecessor ever had before, into the hearts of the southern star clusters and nebulae that Bailey loved to explore. In the spring of 1897, he asked Pickering’s official permission to pursue “the variable stars in clusters (or elsewhere) which I have or may discover.” Bailey predicted his proposed study of such stars’ periods might occupy his spare time for many years, during which he would always welcome the director’s assistance and advice.
Pickering approved the plan, without foreseeing its potential as a source of friction between his two camps. Since Bailey had specified variable stars “which I have or may discover,” he became increasingly concerned with their discovery. He and his assistants, DeLisle Stewart and William Clymer, began checking each night’s images to pick out the possible variables before shipping the plates to Cambridge. Soon Mrs. Fleming complained.
“She feels,” Pickering explained to Bailey on September 29, 1897, “that in these cases the credit goes to the Peruvian observers while a large amount of work falls upon her. She is obliged to measure the positions, the variations in brightness, if any, and to identify the individual lines, classify the object and see if it is a catalogue star. She also has to reexamine the plates since the fainter objects, including about half of the peculiar objects, and as many more having slight peculiarities are omitted [from the existing catalogues]. All of this is part of her regular routine work and has been for the past ten years, and much of it could not be done in Peru.
