On a scorching July afternoon in 1878, the moon's shadow descended on the American West, darkening skies from Montana Territory to Texas. This rare celestial event—a total solar eclipse—offered a priceless opportunity to solve some of the solar system's most enduring riddles, and enterprising scientists raced to the Rocky Mountains to experience totality. Some, like University of Michigan astronomer James Craig Watson, hunted for a planet (called Vulcan) that was thought to exist between Mercury and the sun; others, like astronomical artist E.L. Trouvelot, sketched the sun's mysterious corona. Vassar astronomer Maria Mitchell headed west with an all-female team of assistants and a societal goal to achieve—opening the doors of science to women. Even a young Thomas Edison got involved. During the eclipse, he aimed to demonstrate the value of his latest device—an infrared detector called the tasimeter—and to prove himself not just an inventor, but a scientist.

In this excerpt from American Eclipse: A Nation's Epic Race to Catch the Shadow of the Moon and Win the Glory of the World, science journalist David Baron writes about the morning and afternoon just before the eclipse, when national anticipation was at its peak.

 
 

Monday, July 29, 1878 // Morning through mid-afternoon

Across the breadth of the nation, on the morning of the great eclipse, it seemed as if a long-awaited tournament—or battle—was set to commence. New York’s newspapers exuded anticipation. “[I]t will probably be the most interesting and important total eclipse ever seen by man,” The Daily Graphic rhapsodized. The New York Herald explained that scientists would investigate “in a manner never before possible the theories of solar physics.” The front page of The Sun offered the headline THIS AFTERNOON'S ECLIPSE, with the subhead: “Prof. Edison and Other Savants Ready to Watch the Moon’s Passage.”

A rundown of those savants appeared in The Philadelphia Inquirer. “Professors Newcombe and Harkness take charge of the stations at Creston, Wyoming” began the list, which, despite small errors of spelling and location, conveyed a good sense of the field of play. “Professor Langley, with General Myer and Professor Abbe, of the Signal Service, are at Pike’s Peak, and various other points in Colorado are occupied. With these astronomers there are many amateur scientists, and others will make observations independent of the government programme. Professor Young is at Denver, Professor Draper at Rawlings, and Miss Maria Mitchell near by.”

Chicago Times Map depicting the path of the 1878 total solar eclipse.
Courtesy of David Baron // Public Domain

As to the scientific goals for the eclipse, The Chicago Times outlined the most important. “First, the establishment of a relative co-ordinate of the sun and moon”—that is, determining the precise start and end times of the eclipse at different locations, which would enable the Nautical Almanac to update its tables of the moon’s orbit. “Second, the study of the physical constitution of the sun by an examination of the corona and protuberances that jut out from behind the moon when the sun’s disc is wholly obscured.” In this regard, Edison’s tasimeter was a new tool that could offer new insights. “A third matter of interest,” the paper continued, “is the opportunity the total eclipse affords in searching for any planetoid or group of planetoids that may be between Mercury and the sun”—in other words, Vulcan. The Washington Post left no doubt that this last trophy was the most coveted. “Should this body be discovered, it would be one of the greatest triumphs that astronomy could achieve.”

The Boston Globe ended its preview of the day’s event on a patriotic, self-congratulatory note, reminding its readers that eclipses were once seen as omens that portended “accident, the coming of disasters, and tokens of the anger and wrath of the Creator.” Not so in modern, enlightened America. “Science and general education,” the paper asserted, “have banished all the dread which these events inspired.”

 
 

There was ample dread, though, among the scientists at their camps in Wyoming and Colorado. The depths of anxiety experienced by an astronomer in the hours before a total solar eclipse are difficult to fathom. With so much to do and so much to go wrong, emotions can overwhelm. One British scientist who headed an eclipse expedition to Siam in 1875 recalled that, the day before the event, “I could not help sitting down and having a good cry.”

At Creston, William Harkness and his party emerged from their postal-car sleeping quarters to a chilly sunrise and nervously eyed the heavens over the Great Divide Basin. “[N]ot a cloud was to be seen in the deep-blue sky stretching above us in all its purity,” wrote an enthusiastic E. L. Trouvelot. Harkness too was optimistic. “Everything promised well for the eclipse,” he remarked. The men washed up, then sat down for breakfast. A wind blew in from the southwest. It quickly strengthened, propelling dirt airborne. By eight o’clock, the astronomers in the mess tent found themselves and their dishes covered with sand and dust.

Scientists at Rawlins, Wyoming Territory.
Scientists—including Edison (second from right) and Watson (sixth from right)—at Rawlins, Wyoming Territory.
U.S. Department of the Interior, National Park Service, Thomas Edison National Historical Park

Down the tracks in Rawlins, the Draper party scanned the skies. They anxiously watched a cloud bank thicken in the east, but a few hours later—to their relief—it moved off toward the south. By noon, however, the wind picked up here, too, rocking their frail observatory. Even more vulnerable to the gusts was the chicken coop that housed the tasimeter. Edison had spent the weekend carefully adjusting his instrument, but the gale was now undoing his hard work—throwing the equipment out of alignment. Frantic, Edison ran to the neighboring lumberyard and recruited a dozen strong men to carry boards and help him prop up the structure and erect a temporary fence against the wind, which was blowing—in the estimation of one who experienced it—“with the force of a hurricane.”

James Craig Watson and Norman Lockyer, meanwhile, made a last-minute decision to gain a few seconds of totality. Rather than observe the eclipse in Rawlins, they would head to Separation, which sat closer to the midline of the eclipse path and therefore would experience a slightly longer phase of darkness. J. B. Silvis, the Union Pacific photographer, offered his wheeled studio for transport. Hooked to the back of a westbound freight train, the caboose carried the two astronomers to the remote rail stop where Edison had hunted the stuffed jackrabbit. Joining them were several volunteers for the day: Watson’s wife, Annette; D. H. Talbot, the Sioux City land broker; and the two young men from Cambridge, R. C. Lehmann and his friend James Brooks Close. When the train arrived at Separation, Lockyer erected his equipment by the station, in the lee of the large water tank. Watson, with his wife and telescope, headed on to Simon Newcomb’s camp, which sat almost a mile away on the south side of the tracks. Pushing through the thorny brush could not have been pleasant for a man of girth.

 
 

In Colorado, the people of Denver also awoke to limpid skies. Joseph Brinker, the founder of a private school in the city, kept close track of the weather that morning—at six o’clock, he wrote: “Not a cloud”; seven: “Not a cloud”; seven-thirty: “Not a cloud”; eight: “Not a cloud”—but given the experience of recent weeks, no one could be confident that conditions would remain unchanged in the afternoon.

In the forenoon, locals and visitors prepared for the big event. The eclipse’s brief total phase, when the moon would cover the entire surface of the sun, could be viewed safely with the naked eye, but the much longer partial phase required a dark filter for direct observation. To fill this need, Denverites who had been hoodwinked during the recent blue glass craze—sold azure panes to promote their health—now put their poor investment to profitable use; they employed the glass as a solar filter, in some cases fitting it in the bottoms of boxes or the tops of old stovepipe hats. Many children went a different route, collecting shards of clear glass and blackening them over candles. (Neither smoked nor stained glass is deemed safe by modern standards for viewing the sun, but both were commonly used in the nineteenth century.) “Here’s your eclipse glasses,” Denver’s newsboys yelled, hawking their crude wares for pennies and earning one ambitious youngster a reported seventy dollars over the course of the day.

Stereograph card of the Vassar College eclipse party, Denver.
Stereograph card of the Vassar College eclipse party in Denver.
Archives and Special Collections, Vassar College Library // ID No. 08.09.04

Some in the Denver area left early for eclipse excursions into the foothills and mountains, taking with them picnics of bread and cheese. Many more scoped out suitable viewing locations in town. Maria Mitchell chose for her observation post, at Alida Avery’s suggestion, a hill on the edge of the city, just beyond the reach of suburban development. It was a broad, sloping tract of short grass, easily reached by horse and buggy. Once there, the Vassar party had no time to make elaborate preparations. The women set out wooden chairs, erected a small tent for shade, and mounted their three telescopes on tall tripods. (Mitchell had brought with her the same telescope she had used on her home turf of Nantucket in 1847 to discover her famous comet.) The view east offered an endless, empty expanse of plains. To the west lay Denver and the Rockies behind it. Immediately to the south sat a three-story brick building topped by a gabled roof and an ornate cross. It was St. Joseph’s Home, a Catholic hospital operated by the Sisters of Charity of Leavenworth, Kansas. The nuns in dark habits, spying the astronomers in dresses, came over to offer tea.

The city appeared to be on holiday. As the Denver Daily Times had recommended, banks and retail establishments closed their doors. People gathered on rooftops: the post office, the high school, the fire station, the opera house. A crowd estimated in the thousands assembled along the high ground of Capitol Hill, and in that neighborhood could be found the scientific party sponsored by the Chicago Astronomical Society, including the twenty Denverites who had been specially trained to sketch the corona. They sat themselves on the brow of the hill, facing the sun. A rival team of Chicago astronomers placed itself nearby, on the grounds of the Brinker Collegiate Institute, where principal Joseph Brinker continued to enter notes in his weather log.

Eleven-thirty: “Not a cloud.”
Noon: “Single speck of cloud west.”
Twelve-thirty: “Three light clouds west.”
One o’clock: “Number of small bright clouds west.”

A bit over an hour remained until the eclipse began. Looking south from Denver, the growing throngs could see Pikes Peak standing bright and bold against the sapphire sky.

 
 

Up on the summit of Pikes Peak, the assembled scientists were at last enjoying sunshine. Samuel P. Langley and his brother spent the morning adjusting their equipment and modifying their observing plans, given that they had lost a member of their team to illness.

SP Langley and Cleveland Abbe
Courtesy David Baron // Public Domain

That sick participant, Cleveland Abbe, after being evacuated the night before, had been carried not to the base of the mountain but to just below the timberline, where a rustic lodge sat on a lake at an elevation still of about ten thousand feet. At one o’clock in the morning, a doctor arrived to assess Abbe’s condition. He ordered Abbe not to return to the summit, and left two nurses to care for the ailing scientist until he was well enough to descend to the base of the mountain. Abbe then scratched out a note to be delivered to his boss at the top of the peak:

My Dear General;

I am most devoutly thankful to you for the good care that you have taken of me—and Dr Hart of Col. Springs whom you have summoned—seems decidedly of the opinion that you have done wisely. I must not oppose my own will to reason & your orders. I will therefore stay here today and organise some sort of system of observing the eclipse so that you shall have a report from the Lake House as well as the summit. . . . I trust that you will not yourself suffer from the Pike Peak “fever”

I remain yours truly

Cleveland Abbe.

At daybreak, despite having slept in the somewhat thicker oxygen at slightly lower altitude, Abbe remained weak and faint, yet he was determined to be again what he once was: an astronomer. At noon, he arranged to be carried outside and laid dramatically on a southwest-facing slope with his head propped up. His telescope—a fine instrument made by Alvan Clark & Sons—was still on the summit. All he could rely on were his poor eyes and imperfect spectacles.

 
 

According to calculations by the Nautical Almanac, the eclipse was set to commence in Rawlins shortly after 2:00 p.m. local time, and in Denver at around 2:20. The event’s beginning, like the start of the transit of Mercury, would be barely perceptible—the moon would at first appear like a subtle dent, or flattening, along the sun’s western edge. Across the region, everyone watched and waited. The skies held clear, and for those fortunate enough to be in the path of totality, it promised to be quite a show. “[A]t last we were among the favored mortals of earth,” one Colorado newspaper remarked.

The rest of the nation was less favored—those outside the shadow path would not witness a total eclipse—but everyone would see at least a partial eclipse, weather permitting. Sidewalk vendors in Chicago, St. Louis, Boston, and elsewhere did a brisk business in eclipse glasses. “Here ye are now,” a hawker cried in Manhattan, “blue glass only three cents apiece; all ready to look at th’ eclipse—three cents apiece.”

In the late afternoon, when the partial eclipse was set to begin in New York, the city’s focus shifted upward, as the Herald described:

Portly bankers about to start for home paused on their office steps and turned their eyes above the money making world; merchants stood in the doorways of their busy stores, alternately consulting the face of their watches and the face of the sky; clerks and messengers, hurrying along the crowded streets, ceased to knock and jostle one another and with upturned faces and a blissful forgetfulness of business stood gazing all in one direction, while shop girls, escaping from the toilsome factory, caught a [momentary] glimpse of the heavens above and stalwart policemen stood boldly by frightened French nurses and their infant charges. Even the stage drivers forgot for a single moment to crane their necks and beckon enticingly to passing pedestrians, in the hope of securing another passenger and another fare.

Across the land, as America’s attention was drawn to the higher spheres, an otherwise typical workday assumed a new and exotic countenance.

The cover of David Baron's 'American Eclipse.'

Excerpted from American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World by David Baron. Copyright © 2017 by David Baron. With permission of the publisher, Liveright Publishing Corporation. All rights reserved.