From the Bookshelf of Around the World in 80 Books…

Although no high-altitude astronomical observatory yet existed in the United States, the federal reservation at Pikes Peak was home to the world’s highest meteorology station, maintained at 14,000 feet by the U.S. Army Signal Corps. This made Pikes Peak the only American mountain where particulars of weather (beyond the statistic of annual rainfall) were known. When Pickering’s party of five men ascended in August, leading mules laden with scientific instruments, they encountered a snow squall, a hailstorm, and a thunderstorm they described as violent. Over the course of the month, they camped and compared conditions on three peaks in the region by various means, such as a sunshine recorder William had modified as a complement to a rain gauge, and also by photographing the sky through a 12-inch telescope. Conditions did not seem optimal. What was worse, rumor had it that Pikes Peak might be turned into a state tourist attraction, and be overrun with non-astronomers.

Along with measuring the distances between the lines and converting them to wavelengths, she was expected to classify each spectrum according to Mrs. Fleming’s criteria. But Miss Maury had so much more detail to work with that she could not confine her impressions to those parameters. Some of the lines she looked at were not simply thick or intense, but also hazy or fluted or otherwise noteworthy. Such nuances surely deserved attention, for they might illustrate as yet unsuspected conditions in the stars.

She had willed her country house in Dobbs Ferry to a nephew on the Palmer side, and although she left legacies to niece and nephew Carlotta and Draper Maury, she made no allowance for their older sister, Antonia.

The bulk of the Andes expedition supplies—everything from photographic plates to prefabricated buildings—traveled with Marshall from New York to the Isthmus of Panama, then overland, past the recently aborted French canal effort and the graveyards of fever victims to another ship bound for Callao, near Lima.

The party rode the Oroya Railroad twenty miles east from Lima to Chosica, and from there the Bailey brothers ascended on foot and by mule to elevations of 10,000 feet or more. Their native guides nursed them through bouts of altitude sickness with an effective local remedy, namely the odor of bruised garlic. No particular peak impressed Bailey as ideal, but he needed to seize the good weather of the dry season, and so settled for a nameless mountain with the least obstructed view. It stood just over 6,500 feet high, barely accessible by a path that switchbacked up and around for eight miles. The Baileys labored alongside a dozen locals for three weeks to improve the route from the hotel in Chosica to the site, and then helped drag eighty loads of equipment up that road to the makeshift observatory. When the family moved in on May 8 along with their Peruvian assistant, two servants, cats, dogs, goats, and poultry, their only neighbors were centipedes, fleas, scorpions, and the occasional condor. They relied on a muleteer for daily supplies of water and food.

“I advised Mrs. Bailey and Irving to keep quiet and there would be no harm done and so it turned out. The revolutionists behaved with great moderation and offered us no indignity whatever. We were sent back to Mollendo however while the men followed us in another train which they had captured. When near the town they left us locked in the car and forming in line marched in and took the place in a few minutes. Mollendo is said to have a population of about 3000 but there were only 15 soldiers and they surrendered after about a hundred shots were fired.”

In 1911 Miss Leavitt tracked the step-by-step variation in another nine stars on the glass plates. As before, the brighter variables took the longest times to cycle through their variations. She plotted the numbers on a graph, with period lengths along the x axis, maximum and minimum magnitudes on the y. Connecting the dots, she got two smooth curves, and when she reduced the periods to a logarithmic scale, her curves snapped into straight lines. The trend among Miss Leavitt’s stars was real. Pickering called it “remarkable” when he announced her results in a Harvard College Observatory Circular on March 3, 1912. He used the word “law” to describe the finding she had demonstrated for twenty-five stars in the Small Magellanic Cloud: The brighter the magnitude, the longer the period. It meant that certain types of variables telegraphed their true magnitudes in the duration of their light cycles. Those stars heralded the coming of distance markers in the farther reaches of space. As soon as astronomers learned the key to the stellar code—the degree of brightness linked to each period—they could determine the stellar magnitudes by watching a clock, then leap the interstellar distances on the wings of Isaac Newton’s inverse square law: a variable only one-quarter as bright as another of the same period must lie twice as far away.

“When the names of committees were read,” wrote Miss Cannon, “I was very much surprised to find that I was put on the Committee on Classification of Stellar Spectra—and one of the novel experiences of the summer was to meet with this Committee. They sat at a long table, these men of many nations, and I was the only woman. Since I have done almost all the world’s work in this one branch, it was necessary for me to do most of the talking.”

A chance encounter with ants on Mount Wilson briefly turned Shapley’s attention from the very big and distant to the small and close at hand. While watching patrols of trail-runner ants traverse the back of a concrete building, he noticed that they slowed from a run to a walk as they passed through the shade of the manzanita bushes. At first he presumed the ants were enjoying a cool respite, just as he was doing at that moment. “I began to wonder about this, however,” he recalled in his autobiography, “and soon I got a thermometer and a barometer and a hydrometer and all those ‘ometers,’ and a stop watch. I set up a sort of observing station while resting and getting ready for another night’s tussle with the globular clusters.” Shapley found that the ants set their pace by the ambient temperature. The higher the mercury, the faster they ran, even when carrying loads. No other factors, such as air pressure or humidity, affected their rate of travel. “I found it great fun to watch them.” Recording his ant observations as carefully as he treated any other scientific phenomenon, Shapley arrived at a temperature-speed ratio. He clocked ants in 35-degree cold (Liometopum apiculatum on the edge of a snow bank) and 103-degree heat (Tapinoma sessile in the den of Shapley’s Pasadena home, where he stripped off his clothes and turned up the thermostat to test the limit of the ants’ tolerance). He claimed he could tell the air temperature to within one degree by watching half a dozen ants pass through his “speed trap,” and he published his data on ant thermokinetics in the Proceedings of the National Academy of Sciences.

In time Shapley came to see the globular clusters as the scaffolding of the cosmos. Scores of clusters attending the Milky Way. Some hovered above the broad flat plane of stars, while others dipped below it. Together, they described an enormous halo enveloping the entire galaxy. Shapley could tell by the distribution of the clusters that his own vantage point—atop Mount Wilson, riding planet Earth around the Sun—stood nowhere near the center of the Milky Way. Were he situated at the galactic center, he reasoned, he would see the clusters evenly spaced around him. As it was, when he looked in one direction he saw a sparse string of clusters, and in the opposite direction the “cluster of clusters” in Sagittarius. He concluded the center must lie in that direction. The Sun, though the center of the solar system, was not the hub of the universe. “Some of my series of papers on globular clusters published in 1917 and 1918 were rather revolutionary because the findings opened up a part of the universe that had not been known before,” he wrote of his bold speculation. In Shapley’s new cosmic picture, “the solar system is off center and consequently man is too, which is a rather nice idea because it means that man is not such a big chicken. He is incidental—my favorite term is ‘peripheral.’”

When the female computers of the Harvard College Observatory come up in present-day conversation, they are often portrayed as underpaid, undervalued victims of a factory system. Pickering stands accused of giving them scut work that no man would stoop to do, yet this is far from true. Before astronomy morphed into astrophysics around the turn of the twentieth century, both men and the few women engaged in the science were willing slaves to routine.