^{Excerpted from David Baron’s forthcoming book American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World (Liveright).}

On July 28, 1878, America’s preeminent scientists assembled along the nation’s western frontier, ready for the total solar eclipse that would occur the following day. These intrepid men—and a handful of women—had trekked to Colorado and Wyoming in an era of Indian wars and train robberies to stand in the fleeting shadow of the Moon. They planned, during three precious minutes of midday darkness, to aim their telescopes and spectroscopes skyward in an effort to solve mysteries of the Sun and Solar System, and they hoped to make discoveries that would elevate their young country to an honored place on the global stage. But on this day before the eclipse, the scientists confronted a serious cause for worry: the weather.

Cumulus clouds “hovered over our fair city like birds of ill omen,” wrote an observer in Denver, “reducing to zero the hopes of astronomers, rousing the ire of many of our citizens and exciting the anxieties of all.” A run of storms in recent days boded ill for the eclipse because even a single cloud at the crucial moment could obscure the view and render the entire enterprise worthless. The unsettled weather rattled Thomas Edison, who was in Wyoming, where he planned to use his latest invention—an infrared detector called a tasimeter—to study the eclipsed Sun. The rain and hailstorms hampered the preparations of Maria Mitchell, the acclaimed Vassar professor, who was in Denver with an all-female astronomical party that she hoped would serve as a public demonstration of women’s abilities in science. The storms threatened to wash away a group of Princeton scholars encamped nearby along Cherry Creek. But of all the scientists bemoaning the inclement weather on that day before the great eclipse, the one who agonized the most—whose life was actually endangered by the atmosphere—was a pioneering meteorologist named Cleveland Abbe, the very man who had predicted clear skies.

The field of meteorology was admittedly immature and imperfect in 1878, but scientists had begun to understand how weather systems formed and moved, and the telegraph made real-time storm warnings possible. The head of the Smithsonian, Joseph Henry, had taken early steps in this direction in the 1850s, when he arranged for an assemblage of telegraph stations each morning to wire local weather conditions to Washington, where the information was posted at the museum (using colored cards on a large map) and published in the newspaper. The continually updated chart gave a general sense of storm systems moving across the country, but the Smithsonian did not issue formal forecasts. The federal government took on that responsibility a decade later, when a nascent weather service rose from the ashes of the Civil War.

During the war, Union commanders gathered information on Confederate troop movements with the help of a specially trained team—the Army Signal Corps—whose men climbed high hills and church steeples to scan the terrain and send back coded messages using flags, torches, and telegraphs. When the war ended, such skills were no longer in demand, but the Signal Corps’ leader, General Albert J. Myer, was an astute political operator. With his team’s budget slashed and its very existence threatened, he sought a new peacetime role. He found it in the late 1860s, when a spate of shipping disasters prompted Congress to call for the establishment of a federal storm-warning system. Myer argued that his corps possessed just the skills required: it could gather meteorological data at military posts across the country and then telegraph those statistics back to a central clearinghouse, “giving the presence, the course, and the extent of storms . . . as it would, in time of war, those of an enemy.” His lobbying succeeded. On February 9, 1870, President Ulysses S. Grant signed legislation creating America’s first national weather service. It would be operated by the Army Signal Corps.

General Myer had secured a fresh mandate and a vastly increased budget. What he lacked was a meteorologist.

Cleveland Abbe had not started his career in meteorology. His first love was astronomy, an odd passion for a severely nearsighted boy. After college and graduate school, he sought a permanent, paying job in the field, a quest that proved a long and protracted struggle. Finally, in 1868, he landed what appeared to be—on paper, at least—the ideal position: director of the storied Cincinnati Observatory, whose cornerstone had been laid in 1843 by an elderly John Quincy Adams. By the time Abbe arrived, however, the building was all but abandoned, its windows broken and its roof leaking. Out on the portico, one of the Greek columns was tipping over.

Abbe began repairs to the edifice, but he could not fix a bigger problem, the area’s worsening air pollution. Cincinnati—dubbed Porkopolis—was a booming city of meatpackers and brewers, and thick smoke often blanketed the sky. Since atmospheric conditions dictated how much one might see through a telescope, Abbe grew interested in meteorology, and he devised a plan to track the weather in Southwest Ohio. With the help of observers who telegraphed data from a broad geographic region, Abbe drew up daily forecasts—he called them probabilities—and, beginning in September 1869, he offered the service to area newspapers and private subscribers. For his efforts, this fledgling weatherman, though thirty years old, earned a fondly geriatric nickname: “Old Probabilities.”

Cleveland Abbe had created something historic—the first regular weather forecasting service in the U.S.—but within a year the chronically cash-strapped Cincinnati Observatory was forced to abandon the venture, and Abbe too was soon dispatched, placed on unpaid leave. General Myer, just then seeking to create a weather service on a national level, offered Abbe a job as his chief meteorologist.

At last finding stable employment, Abbe moved to Washington. Recently married, he soon fathered a son, then two more. From his respectable salary he bought a sizable townhouse on I Street. His office was a short walk away, on G Street, where the Army Signal Service (as the Signal Corps had now come to be known) occupied a three-story brick building topped by weather vanes, rain gauges, wind meters, and other “toys which excite the envy of all the neighboring boys,” as one observer put it. A tangle of telegraph wires led inside, funneling in weather reports taken simultaneously at meteorological stations across the U.S. The reports arrived thrice daily, setting off a frenzy of work among a half dozen clerks. Standing at desks, they mapped precipitation, clouds, and wind velocity; drew isobars and isotherms to reveal patterns of air pressure and temperature; and then Abbe or one of the forecasters he trained would deduce how the weather was likely to change over the next day or two. Within an average of one hour and forty minutes, the latest forecast was ready—telegraphed to the press for publication nationwide.

Cleveland Abbe’s new job earned him a comfortable life and the respect of the scientific community, but he bristled under the office rules. He was a civilian of academic bent stuck in a military hierarchy. Whereas Abbe was gentle and bookish (his favorite pastimes were long walks and croquet), General Myer was rigid and domineering. While Abbe argued that the Signal Service must do more than just churn out forecasts—it should conduct basic research to advance the field of meteorology—Myer evinced little interest in theoretical studies. And there was another matter that, for Abbe, must have chafed. His superior had usurped his nickname. The newspapers had taken to calling General Myer “Old Probabilities.”

One summer evening in 1874, General Myer stopped by Abbe’s home. When a servant informed the visitor that the man of the house had already gone to bed, the general laughed—“What, so early?”—and left. The next day, Abbe recounted the incident in a letter to his wife, who was away on a seaside vacation. “Somehow I always feel better when I thus miss seeing him,” Abbe admitted. “I suppose I am foolish & wicked but I can’t help pining for freedom & a telescope.”

In early 1878, as astronomers began planning for the total eclipse that would cross the American West (painting a trail of darkness from Montana Territory to Texas), they called on the Signal Service for an obvious reason—to help identify viewing posts with good odds of clear skies. Cleveland Abbe took on the job, which required the compilation and analysis of historical data from weather stations that fell within or near the computed path of the moon’s shadow. According to Abbe’s math, southern Wyoming should enjoy a 79 percent chance of favorable conditions at the time of the eclipse. At Denver, the numbers were less optimistic, but he still calculated better than even odds of a clear view, at 60 percent. The Signal Service issued these figures, and many others, in a circular that it distributed to the government and the press.

But Abbe, the frustrated astronomer, aspired to do more than provide advice; he hoped to observe the eclipse himself. General Myer was interested in the eclipse, too— after all, it was only appropriate for the nation’s meteorological bureau to use the event to study the Sun, since the Sun drives the weather on Earth—and he immediately focused on a prominent geographic feature that sat in the middle of the eclipse path in Colorado. This was Pikes Peak, which rose more than fourteen thousand feet above sea level and held on its top a Signal Service meteorological post, the highest-altitude weather station on the planet. Manned year-round and connected to the outside world by a seventeen-mile telegraph line, the post imposed harsh duty on its small staff of resident soldiers, who endured electrical storms, hurricane-force winds, frostbite, and the nausea, headaches, and dizziness brought on by the thin atmosphere. Myer hoped to go to Pikes Peak himself, but even if he could not, he wanted another qualified observer on the summit. On this rare occasion, General Myer and his chief scientist saw eye to eye. They agreed: Cleveland Abbe should go to Colorado. He should climb the mountain to observe the hidden Sun.

On Friday, July 20, 1878, Cleveland Abbe arrived in Colorado Springs, near the base of Pikes Peak, and checked into the Crawford House. The hotel, at two dollars a night, did not especially impress him, but he was pleasantly surprised by the city—its irrigated yards, its energetic spirit. As for the weather, it could hardly have been better. “This morning the sky is everywhere as clear as a bell and the blue is such a deep fine solid blue that it’s inspiring to an astronomer to look at it,” he wrote to his wife on Saturday. Less fine were his preparations to ascend the mountain. “There’s a good deal of confusion,” he acknowledged.

Abbe was not to be the sole astronomer on the summit. Samuel Pierpont Langley, director of Pennsylvania’s Allegheny Observatory, knew Abbe from the days when they both toiled as novice directors at poorly funded astronomical institutions along the Ohio River. The two men arranged to join forces on Pikes Peak. “It’s first-rate;—your going;—we’ll have a time—hurroo!” Langley wrote to Abbe the month before the eclipse, then received a kind offer of logistical help from the Signal Service. “[General Myer] takes pleasure in offering you the hospitalities of the Signal Station at the summit for such time as you may need,” read the letter from Washington dated June 13.

Several weeks later, however, when Langley reached Colorado, he found the local Signal Service officers unprepared for his arrival. He had brought along an assistant— his brother—but was told “there was no room for [either of] us in the Signal Service station on the summit.” He had also brought twelve hundred pounds of equipment, and—as he wrote in frustration—“The distance to the Peak was, as we now learned, 18 miles by a foot-path. . . . No wheeled conveyance was possible.” This was not the situation he had anticipated, but it was too late to relocate his observation post, so an arrangement was made to hire burros. The Langley brothers repacked their equipment into smaller boxes, which were then suspended between pairs of donkeys and ferried to the peak by drivers who hurled rocks and profanities at the animals to keep them plodding up the narrow trail. The rugged path crossed a raging mountain stream, angled up a deep gorge, passed waterfalls and crags and snowfields, and finally emerged above the timberline to reveal vast meadows of alpine wildflowers. At the summit, the Langleys—soon joined by Cleveland Abbe—found the weather station to be a small stone hut, overcrowded and half in ruins. Surrounding it was a broad expanse of jagged boulders. Abbe had brought tents, but there seemed to be no suitable spot to pitch them, so the men constructed platforms out of firewood. They covered the wood with damp hay, then tied the canvas to the rocks with wire. The ensuing days brought occasional moments of pleasure. The three scientists gazed down and east across the plains, which stretched like an ocean to a shoreless horizon. They looked west over forested valleys, shining lakes, and snowcapped peaks. They marveled at the play of light and shadow on the clouds that rolled by. But the remainder of the time—almost all of it, in fact—was torment. The weather, as Abbe so delicately phrased it, “was more than usually unpropitious.” He telegraphed Washington with updates each evening at nine. On Wednesday, he wired: “Cold rain all this afternoon.” On Thursday: “Rather disagreeable weather.” Friday: “Occasional glimpse of the sun, but mostly snow, fog, and clouds.” And Saturday, just two days before the eclipse: “Two snow storms with gales endangering tents and instruments. No satisfactory glimpse of sun today. Very little progress in preparing for Monday.”

The telegrams did not adequately convey the misery. At night, under damp blankets, the men struggled to sleep while the wind roared and shoved—intending, it seemed, to blow them, tents and all, off the mountain. In the day, during brief intervals of sunshine, the astronomers strove to set up their telescopes, but as soon as they unwrapped the equipment from its protective canvas, the clouds again unleashed rain or hail. (To prevent his telescope from rusting, Samuel Langley covered its steel parts with lard.) A reporter who scaled the mountain to interview the scientists declared them “the bluest party of astronomers that could have been found in the great state of Colorado. They had almost abandoned the hope of a favorable view of the eclipse, and were in a state of profound and unanimous disgust.”

The worst of their suffering was not emotional, but physical. In the thin atmosphere, their hearts raced, and the slightest exertion left them gasping for air. “I lay awake the second night, drawing long breaths, in the vain attempt to breathe once satisfactorily,” Samuel Langley wrote, “and remember thinking occasionally of a mouse I once saw experimented on, under the bell of an air pump, with a sympathy, born of new experience.” The men were being starved of oxygen. They developed acute mountain sickness. “[W]e felt constant and severe headache, and nearly every symptom which attends sea-sickness,” Langley recalled.

After a few days, the Langley brothers gradually began to acclimate, but not so Cleveland Abbe. His symptoms steadily worsened until, on Sunday morning—the day before the eclipse—he awoke in his tent to paroxysms of pain in his head and upper back, and he was unable to rise. Abbe’s inability to stand suggests that he had developed a dangerous condition known today as high-altitude cerebral edema. His brain was swelling, squeezing against the skull. The resulting pressure can rapidly cause confusion, hallucinations, coma, and—especially if one spends another night at high altitude—death.

The underlying physiology of Abbe’s condition was not understood in 1878, but John W. Langley had been trained as a physician, and he could tell that Abbe’s infirmity was potentially lethal. Langley implored Abbe to evacuate to a lower altitude, but Abbe refused, adamant that he should remain on the peak for the eclipse. His stubbornness was understandable given that he had come so far, but he likely too was suffering from impaired judgment, a common symptom of high-altitude cerebral edema. So Abbe remained in his tent, under the illusion that with rest he would recuperate.

Meanwhile, some eight thousand feet below, beginning his own ascent of the mountain, was the man Abbe preferred to avoid when possible. General Myer, “otherwise known as ‘Old Probabilities,’” as a Denver newspaper wrote, had arrived in Colorado the previous day. At 5:00 p.m., the general emerged on the summit and found his chief meteorologist an invalid. Whereas the Langleys could only try to persuade Abbe to evacuate, Myer had the authority to issue a command, which he did. Abbe was thus loaded on a stretcher. By 6:30, four men were carrying him like pallbearers down the rocky, zigzag trail.

Flat on his back on the litter, Cleveland Abbe faced skyward through woozy consciousness. As the Sun set for its final time before the great eclipse, he watched the heavens darken. Although in his hasty retreat from the summit he had forgotten his strong spectacles for stargazing, he could still, with his weaker prescription, pick out the constellations: Cygnus, Lyra, Aquila, Cassiopeia. The Milky Way, a vivid band across the firmament, shone auspiciously-evidence, at last, that the skies had cleared.--DB