CHAPTER FOUR

The American Prime Meridian

THE METHODS of computation migrated to North America with the navigators who guided the ships across the North Atlantic and the surveyors who delineated the European claims upon the continent. Throughout the eighteenth and nineteenth centuries, the Greenwich Observatory and the British Nautical Almanac served as sources of computational techniques for those traveling west. The observatory had employed Charles Mason before he departed with Jeremiah Dixon to survey the border between Pennsylvania and Maryland.¹ One of the almanac computers, Joshua Moore, emigrated to the United States and corresponded with President Thomas Jefferson on subjects mathematical.² The British Nautical Almanac itself was reprinted in Salem, Massachusetts, and was freely available for purchase at the ports of Boston, Nantucket, New York, and Philadelphia.

The models of organized computational labor emigrated more slowly to the United States than did the mathematical methods of astronomy, navigation, and surveying. Through the first decades of the nineteenth century, American science was the work of individuals rather than organizations, the effort of Benjamin Franklin or Thomas Jefferson rather than of an almanac office or the computing factory of an observatory. “Amongst few of the civilized nations of our time have the higher sciences made less progress than in the United States,”³ observed the French writer Alexis de Tocqueville (1805–1859). When de Tocqueville visited the United States in 1831, he found a country that had supported only a few large scientific projects, most notably the survey expedition to the Pacific Northwest of Meriwether Lewis and William Clark. De Tocqueville drew the general lesson that “those who cultivate the sciences amongst a democratic people are always afraid of losing their way in visionary speculation,” but in reaching that conclusion, he failed to understand the connection between the nature of American democracy and large scientific projects. Even in the early nineteenth century, the big scientific endeavors received government patronage. In England, the crown’s government had provided financing for the Nautical Almanac, the Royal Observatory, Babbage’s Difference Engine, and even the construction of the railroads. In the United States, the citizens deeply distrusted the power of governments and national institutions. Just before de Tocqueville visited the United States, the American Congress had rejected a proposal to create a national university and national observatory. The proposal had been drafted by President John Quincy Adams, who had a deep interest in science and learning. Adams was well read in the classic literature of political philosophy, but such knowledge did not make him a skilled leader. “It would have been difficult … to propose a more unpopular measure,” observed historian Hunter Dupree.⁴

Before 1840, the United States government operated only one permanent scientific agency, the Coast Survey Office. As the name implied, the Coast Survey was responsible for cataloging harbors and navigational hazards of the Atlantic shore. It had been founded in 1807 but had accomplished little, as it was bedeviled by a weak leader and vacillating congressional support. Congressional interest in science changed only as the country’s population began to move from farm to workshop. In 1800, less than 5 percent of the adult population was involved in manufacture. By 1840, that fraction had risen to 25 percent. The new workers brought to power the Whig Party, a group that advocated improvements to the national infrastructure, including the construction of roads, the digging of canals, the expansion of ports, and the creation of scientific institutions. The navy was the first government office to be touched by this political shift. In 1842, the naval secretary reorganized the entire command structure of the navy and created two scientific offices. The first was a small ordnance proving ground, a testing place for cannons and mines. The second was an astronomical observatory, originally given the name of National Observatory, though the title of “National” was soon changed to “Naval.”⁵

The navy’s actions were soon followed by a major reorganization of the Coast Survey Office. In 1843, Congress gave the survey office an expanded budget, a broader scope of operations, and a new, dynamic superintendent.⁶ The next year brought the founding of the Smithsonian Institution (1844) as an office for the “increase and diffusion of useful knowledge among men.”⁷ These government agencies were matched by two important private scientific institutions, the Harvard Observatory (expanded in 1843) and the American Association for the Advancement of Science (1848). The last major scientific institution of the 1840s, the American Nautical Almanac Office, was created in the last year of the decade.⁸

“The peculiarity of American institutions,” wrote the historian Frederick Jackson Turner, “is the fact that they have been compelled to adapt themselves to the changes of an expanding people—to the changes involved in crossing a continent, in winning a wilderness, and in developing … out of the primitive economic and political conditions of the frontier into the complexity of city life.”⁹ In many ways, the founders of the early American scientific institutions were working in on intellectual frontier, borrowing and adapting ideas from their European counterparts. The Coast Survey purchased equipment from France and Germany. The American Association for the Advancement of Science took its name and purpose from a British organization whose founders included Charles Babbage. The American Nautical Almanac based its operations upon the ideas of Nevil Maskelyne. Not all such ideas were successful in their transit across the Atlantic. The U.S. Navy mistakenly constructed its new observatory on a river bluff site that resembled the placement of the Royal Observatory in England. Unlike the park at Greenwich, the navy’s perch over the Potomac River had little to recommend it. From the first nights of operation, astronomers complained that river mists fogged telescope lenses and that marshes bred swarms of infectious mosquitos. They might have borne such trials more bravely if the site had had the advantages of Greenwich, such as easy proximity to a navy yard or the view of ocean-bound ships. The only vessels that passed the American observatory were canal barges bound for the Ohio Valley, boats that did not need an almanac in order to find their way.

Though all of the American scientific institutions of the 1840s were touched by the “primitive economic and political conditions” of the North American continent, they were more profoundly shaped by competition with European institutions. This is especially true for the largest computing organization of the age, the American Nautical Almanac. The almanac was generally viewed as a practical means for improving the navigational skills of the navy and the mercantile fleet. “But for the Nautical Almanac of England or some other nation,” claimed one supporter, “our absent ships could not find their way home nor those in our ports lift their anchors and grope to sea with any certainty of finding their way back again.”¹⁰ Yet many individuals saw the almanac as a way of demonstrating America’s intellectual accomplishments. It “would be a work worthy of the nation,” wrote one scientist, “and might engage our ablest astronomers and computers.”¹¹ Such thoughts were echoed by the political leaders. An almanac “was important to the character of the country,” argued one member of Congress, “important to the national pride, national honor and independence.”¹²

The almanac was shaped by two individuals, Lieutenant Charles Henry Davis (1807–1877) of the U.S. Navy and Harvard College professor Benjamin Peirce (1809–1880). The two were related by marriage and lived in neighboring houses in Cambridge, Massachusetts.¹³ Their front doors were just a few steps from Harvard Yard; their back windows looked across the fields to the distant ships at the docks of Cambridgeport. Davis’s son recalled that children moved freely between the two homes and that their families “dwelt almost as one.”¹⁴ Their friendship had begun some fifteen years before, when Davis had taken a house in Cambridge following an extended voyage. He had once been a student at Harvard College, but he had left without a degree in order to take an officer’s commission. During his travels, he had retained an interest in learning. One of his commanders described him as “intelligent in his profession, energetic in his character, and devoted to the improvement of his mind.” While on an early voyage, he studied navigation, learned “French, Spanish and a good smattering of Italian,” and read the complete works of William Shakespeare.¹⁵ In 1840, he had returned to Cambridge for a year of intensive mathematical study with Peirce. According to his son, Davis did not always “follow the transcendent flights of Peirce’s genius” but persevered in his study and ultimately acquired “a working familiarity with mathematical tools.” For his efforts, he received a Harvard degree, conveniently backdated to suggest that he had graduated with his original classmates.¹⁶

9. Lieutenant Charles Henry Davis of the American Nautical Almanac

By all appearances, Benjamin Peirce was an unlikely friend for Davis. Davis was a practical and disciplined officer from a privileged Boston family. No sign better captured his bearing than his prominent moustache, groomed with military precision. Peirce was one of the “bearded ancients” of Harvard College and sported an unruly head of hair. His lectures were rambling, difficult affairs that were often incomprehensible to students. The one quality that may have caught Davis’s sympathy was Peirce’s ability to maintain his intellectual bearings. In the 1840s, Cambridge was awash in the Transcendental movement, the philosophical current that saw in every aspect of nature “a symbol of some spiritual fact.”¹⁷ Peirce befriended the leader of the Transcendentalists, Ralph Waldo Emerson (1803–1882), and occasionally referred to God as the “Divine Geometer,” but he never lost sight of the theories of Newton or the mathematics of calculus.¹⁸

When the American Nautical Almanac began operations in July 1849, the navy appointed Charles Henry Davis as the first superintendent. In turn, Davis selected Peirce as the chief mathematician and established the almanac office in Cambridge, Massachusetts.¹⁹ When called to explain why he did not place the office in Washington, Davis wrote that Cambridge had “the best scientific libraries of the country—an indispensable aid in laying the permanent foundation of a work of this magnitude and importance.”²⁰ Davis may have been rationalizing a decision that was convenient for himself and for Peirce, but he clearly wanted to create a superior publication with a staff of “first class computers.” There would be no former hairdressers on his staff and no boy computers like those found at Airy’s observatory. He stated that his computers “must be gentlemen of liberal education and of special attainments in the science of astronomy.”²¹

At the start, Davis tried to recruit mathematicians for the almanac staff. He wrote to professors at the University of Virginia, Princeton, Rutgers, Columbia, and the Military Academy at West Point, asking each to serve on the almanac staff.²² To this list he added the name of one foreigner, the French astronomer Urban Jean Joseph Le Verrier (1811–1877). In 1849, Le Verrier was basking in the fame of having discovered the planet Neptune, an event that dominated the public imagination of the 1840s. He was a mathematical astronomer, not an observer, and his discovery was an event of “pure calculation,” “the grand triumph of celestial mechanics as founded on Newton’s law of gravitation.”²³ Le Verrier had estimated the location of the planet by analyzing variations in the motion of Jupiter, Saturn, and Uranus and by hypothesizing the existence of an undetected body in orbit around the Sun. He had projected the possible location of this planet and sent his estimate to the observatory at Berlin. The German observers had found the planet with a single night of searching. They waited a second night in order to confirm their observation and then wrote to Le Verrier, “Monsieur, the planet, of which you indicated the position, really exists.”²⁴

The discovery immediately pushed Le Verrier into public view. Many urged that the planet should be named Le Verrier, just as the comet of 1682 had been named for Edmund Halley. Observers spent their nights studying the barely perceptible motion of the planet and looking for evidence of moons. The news penetrated so deeply into public consciousness that it even reached the backwoods of Massachusetts, where it received a disparaging response from Henry David Thoreau (1817–1862) at Walden Pond. In the manuscript of Walden, Thoreau dismissed the mathematics that might allow an astronomer “to discover new satellites to Neptune” but “not detect the motes in his eyes, or to what vagabond he is a satellite himself.”²⁵ Such words failed to touch Le Verrier’s reputation. Had he been willing to join the American almanac staff, Le Verrier would have brought substantial fame and prestige to the periodical, but he declined Davis’s request. Davis was ultimately rejected by all of the mathematics professors on his list, save for Benjamin Peirce.²⁶

To build his computing staff, Davis turned to students, independent astronomers, and skilled amateurs. These individuals were not true members of the country’s small scientific community, but each of them had the promise of a successful future. Most of them were either friends or former students of Benjamin Peirce. The list included a young mathematical prodigy from Vermont, Henry Safford (1836–1901); a future president of the Massachusetts Institute of Technology, John Runkle (1822–1902); and a professor, Joseph Winlock (1826–1875) of Shelby College in Kentucky. Though Davis had not been able to convince the discoverer of Neptune to join the almanac staff, he was at least able to recruit an astronomer who had achieved some fame by computing Neptune’s orbit, Sears Cook Walker (1805–1853).²⁷

In the fall of 1846, the fall when Le Verrier announced the existence of Neptune, Walker was an assistant astronomer at the newly opened Naval Observatory in Washington. This was not a job that he had intended to take, but he had little choice in the matter. For nearly twenty years, he had worked for the Pennsylvania Company for Insurances on Lives and Granting Annuities. By day, he was an actuary, a mathematician responsible for estimating the risk and profit of insurance policies. By night, he was an amateur astronomer, using the telescopes of the Philadelphia High School to study the moon as it passed in front of stars.²⁸ At the time, the high school observatory was the best equipped in the nation. Most of the instruments had been donated by Walker, who was making a substantial fortune in his actuarial practice. This life had come to an end in 1845, when a “series of unfortunate investments and commercial operations led to most disastrous results.” According to a friend, this disaster left Walker “at the age of forty years utterly without means.”²⁹

Under the best of circumstances, Sears Cook Walker could be difficult. “I have had some differences with him,” wrote Benjamin Peirce, “but they have not blinded me to his great merits.”³⁰ At the Naval Observatory, Walker showed his great skill and his wayward nature. In the fall of 1846, he turned from his observatory duties to consider the planet Neptune. The observatory had been the recipient of small packets of data from the European astronomers, sealed with wax and addressed to the new “National Observatory.” By late fall, he had a substantial collection of data that showed the planet’s slow march across the celestial sphere. Walker decided that he might get a better calculation of the orbit if he could find an earlier observation of the planet, an observation that had been falsely recorded as a star. Using the data he had collected, he spent about three months computing the motion of the planet backwards from its location in 1846. He finally found his prediscovery observation in a 1795 star catalog that had been compiled by Joseph Lalande. The catalog showed a star where Neptune should have been. Using the navy’s telescopes, Walker sought in vain for the star and concluded that Lalande had seen the moving planet instead of a fixed star. With Lalande’s observation, Walker was able to make a refined calculation and show that the planet moved in an orbit that was nearly circular.³¹ The navy treated Walker’s work as a major triumph, the first important accomplishment of its observatory. “The theory of Neptune belongs, by the right of precedent, to American science,” bragged the observatory director.³²

Ironically, the most well-known of the first computers for the American Nautical Almanac was the sole woman, Maria Mitchell (1818–1889). When Charles Henry Davis appointed her to his staff, he presented her credentials to the secretary of the navy as “the lady who lately received from the King of Denmark a medal for the discovery of a new comet.”³³ As an astronomical discovery, the comet was small and unimpressive. It was not even a periodic comet like Halley’s. Once it vanished from the night sky, it was gone forever. Still, the discovery caught the public’s attention as “one of the first additions to science” made in the United States.³⁴ Mitchell was an extraordinary scientific talent, and she lived in one of the few communities that acknowledged a public role for women in nineteenth-century America. There were no other female scientists in the United States and few women in any other field of endeavor. She had discovered her comet in 1847, the year before the 1848 Seneca Falls Conference on the Rights of Women, the event that has often been identified as the start of the American feminist movement. Behind the Seneca Falls Conference lay the Quaker Church, the only religious denomination of the time that allowed women to preach to its congregations. Four of the five conference organizers were Quakers, as were Maria Mitchell and her father, William Mitchell (1791–1869). William Mitchell supported and pushed his daughter in her career, demonstrating what the early feminist Margaret Fuller (1810–1850) called the “chance of liberality” that a father might show to his daughter but a “man of the world” might never show toward his wife.³⁵

William Mitchell was a banker on Nantucket Island and an amateur astronomer. Maria Mitchell recalled that her interest in astronomy was “seconded by my sympathy with my father’s love for astronomical observation.”³⁶ He taught her how to use a telescope, how to reduce data, and how to compute time from the position of the moon. He was a friend of the scientists at Cambridge, including Benjamin Peirce, Charles Henry Davis, and the director of the Harvard Observatory. When his daughter told him that she had identified a comet, he encouraged her to notify the observatory. When she resisted the idea, William Mitchell communicated the discovery himself. “Maria discovered a telescopic comet at half past ten on the evening of the first instant,” he wrote. “Pray tell me whether it is one of George’s [Airy of the Greenwich Observatory]. … Maria’s supposed it may be an old story.” The observatory confirmed that the comet was new and initiated an energetic effort to ensure that Maria Mitchell was given credit for the discovery. The object of their effort was King Christian VIII of Denmark. The king awarded a medal to the discoverer of any comet. In the early winter of 1848, he was preparing to give his medal for Mitchell’s comet to an Italian astronomer. The director of the Harvard Observatory did everything he could to convince the king to change his mind. He enlisted the aid of the Harvard president and the American consul in Copenhagen. Eventually, the king relented and recognized Mitchell as the first to see the comet.³⁷

Charles Henry Davis recruited computers through the end of 1849 and began operations that winter. He organized the staff after the pattern that Nevil Maskelyne had established some eighty years before. Each computer took responsibility for one or two tables. Sears Cook Walker took the computations for Neptune. Benjamin Peirce handled the ephemeris of Mars and the apparent movement of the Sun. Without a trace of irony, Davis asked Mitchell to handle the computations for the planet Venus. “As it is ‘Venus who brings everything that’s fair,’” he wrote, “I therefore assign you the ephemeris of Venus, you being my only fair assistant.”³⁸ John Runkle, the future president of the Massachusetts Institute of Technology, prepared part of the calculations of lunar motion, splitting the task with another computer, just as Maskelyne’s computers had done.

10. Maria Mitchell

For about half of the computers, including Maria Mitchell and Sears Cook Walker, Charles Henry Davis distributed detailed computing plans through the mail. Unlike Maskelyne, Davis did not prepare hand-drawn computing forms. Though he gave the computers a rough idea of how the sheet should look, he let them organize the computations as they desired. “You may fill up the sheets as much as possible, consistently with the clearness,” he told Maria Mitchell, and in so doing “can thus economize on paper.”³⁹ He provided paper and reference books to all of the computers, sending the supplies with a private forwarding company called Adams Express. Mitchell, who had a relatively meager library, often requested books for her work. In December 1849, she asked for a copy of Theoria Motus Corporum Coelestium in Sectionibus Conicis Solem Ambientium (The Theory of the Motion of the Heavenly Bodies Moving about the Sun in Conic Sections) by the German astronomer Carl Friedrich Gauss (1777–1855). This book, one of the last major astronomical texts written in Latin, had a fairly complete discussion of the techniques of astronomical calculations. “I have directed my bookseller to endeavor to get two copies [for the almanac office],” Davis responded, “and will add a third to the list for yourself if you wish it.” He concluded the letter by commenting, “I am glad you read Latin.”⁴⁰

The remaining computers, those who lived near Cambridge, worked at the almanac office. As far as we can determine, this office resembled the rooms of the British Nautical Almanac in London. There were worktables for the computers and a private area for the superintendent. One young computer recalled coming into the Cambridge office on a frosty January morning, taking a “seat between two well-known mathematicians, before a blazing fire.” It was an informal place, where new ideas of mathematics were freely discussed between calculations, as the “discipline of the public service was less rigid in the office at that time than at any government institution I ever heard of.” Each computer was expected to spend five hours a day in the office. “The hours might be selected by himself, and they generally extended from nine until two, the latter being at that time the college and family dinner hour.” All that Davis required was that the work was done on time.⁴¹

The disjointed operation of the almanac, with some computers in Cambridge and some working from home, fit easily into the organizational structure of the navy. Davis kept track of each computer and the progress of his or her work. Four times a year, he would send pay vouchers to the computers that could be redeemed at any naval facility. The letters that accompanied these payments contain gossip, discussions of mathematics, news about astronomy, and even a few quotes from Shakespeare, who was clearly his favorite author. “Enclosed are your vouchers signed by myself,” he wrote to a new computer; “you had better negotiate them with a friendly broker, rather than with one where you hold a relation of Antonio to Shylock.”⁴² Almanac computers earned between five hundred and eight hundred dollars per year for their work. Two of them doubled their income by checking and correcting the work of others in addition to doing their own computations.⁴³

After a year of calculations, Davis could report that work for the first issue, which would cover the year 1855, was progressing nicely. He told the secretary of the navy that his “small corps of computers” was employing the theories of the “illustrious Leverrier,” using the corrections of Airy, and reducing data from Maskelyne. He reminded the secretary that he had already made a special report of “a variation in the proper motion of one of the fundamental stars,” which he claimed “has led to a discovery of particular interest in stellar astronomy.” He summarized his progress by stating, “I have frequently expressed my wish that the Nautical Almanac should in every respect conform to the most advanced state of modern science and be honorable to the country and it is my determination to spare no effort by which this high object can be attained.”⁴⁴

Though Davis was confident that his computing staff would produce an American almanac that rivaled the publications of Europe, others were not so certain. The potential users of the almanac, notably the merchant navigators and the surveyors, were willing to withhold their judgment until they saw the final product. These two groups were concerned about a basic element of the almanac, the location of the prime meridian. All almanacs had to establish a meridian, a line running through the north and south poles that would serve as a reference for the positions of stars. The Connaissance des Temps used the Paris meridian, which passed through the Cathedral of Notre Dame. The British Nautical Almanac was prepared for the Greenwich meridian. Originally, this line had been drawn through the Octagon Room of the Royal Observatory, but it had since moved to the site of a new telescope mount a few yards to the west. The original proposal for the American Ephemeris and Nautical Almanac instructed the navy to publish an “American Nautical Almanac, to be calculated for the meridian of Washington city.”⁴⁵

Davis did not like the idea of a Washington meridian. He preferred to use the Greenwich line, for he felt that it would produce the most accurate longitude calculations. “Our own vessels are constantly meeting those of Great Britain on the great highway of nations,” he noted, “and are in the habit of comparing with them their longitudes.”⁴⁶ By adopting the Greenwich meridian, the computers of the American almanac could use without additional calculations the vast catalogs of star data that George Airy was compiling at the Royal Observatory. However, the Greenwich meridian did not satisfy the computers of the Coast Survey or the surveys of the various American states. They wanted a meridian safely on the North American continent. Their calculations would be most accurate if they could physically measure parts of the meridian and if they could work without an ocean intervening between themselves and their baseline.

From one point of view, the argument between those favoring the Greenwich meridian and those who wanted a Washington meridian was an honest scientific disagreement. Each of the two groups advocated a procedure that was best for its own needs. Each of the procedures would provide an acceptable, though not perfect, solution for the other group. Yet the argument had symbolic and economic aspects beyond the scientific construction of astronomical tables. The symbolic problem was an offshoot of Manifest Destiny and the Monroe Doctrine. The American citizenry saw themselves settling the breadth of the North American continent, from the Atlantic to the Pacific. As settlers moved west, they would use the American Nautical Almanac to survey the territories and set the borders of new states. Congress would insist that those borders be specified from Washington, rather than from a meridian that passed through the suburbs of a foreign capital.

Davis believed that he had a clever compromise to the meridian problem, one that would satisfy both navigators and surveyors. He proposed “to establish an arbitrary meridian at the city of New Orleans, which will be exactly six hours in time, or ninety degrees in space, from the meridian of Greenwich.”⁴⁷ The idea was an elegant technical solution, as it gave the United States its own meridian and allowed navigators to compute their position relative to Greenwich with little extra effort. Davis must have believed that his idea would be accepted without complaint, but just as he was starting the computations, he reported to the navy “that a ‘remonstrance’ against my paper on the American Prime Meridian and against any change from the Meridian of Greenwich is circulated among the merchants and insurers of the cities of Boston and New York for signatures.”⁴⁸

The supporters of the “remonstrance” were uncomfortably close to Davis and his friends. Their leader, Ingersoll Bowditch (1806–1889), was the director of a Boston insurance firm, a friend of Benjamin Peirce, and a financial supporter of the Harvard Observatory. Their objections to a meridian at New Orleans were entirely economic. Bowditch believed that his business would be damaged by the change in meridians. He was a partner in a firm that republished the British Nautical Almanac in the United States. The objections of the other merchants and insurers were more speculative. They were concerned that the ports of Boston and New York would decline if New Orleans had a meridian passing through it. New Orleans already possessed a substantial advantage over the Atlantic ports, as it had a navigable waterway, the Mississippi River, with access to the vast center of the continent. With the meridian, reasoned Bowditch and his supporters, New Orleans would become a destination for ships needing to adjust their chronometers. These ships would divert trade to the south, as none of the captains would want to travel empty.

Davis attempted to counter the claims of Bowditch, but he had lost the battle almost from the beginning. He argued that his proposal was “founded on principles of science” and would contribute “towards improving the safety of navigation, and completing the geography of the seas,” but neither idea swayed his opponents.⁴⁹ The debate had turned toward economic issues and way from scientific merit. In this field, Bowditch held the greater power. By the spring of 1850, Davis had abandoned his idea for the meridian and accepted a solution that divided the American almanac into two parts. The first part, the American Ephemeris, would be computed relative to a meridian that passed through the Naval Observatory in Washington. This meridian would be used by surveyors as they set the borders of Wyoming, Colorado, Oregon, and the other western states. These lines would fall at integral number of degrees west from the Naval Observatory in Washington, rather than from the Royal Observatory in England. The second part of the almanac, the Nautical Almanac, would be prepared using the Greenwich meridian and be used by the nation’s sailors.

The double meridian scheme put extra demands upon the almanac computers, as it required them to prepare more tables, but it had little impact upon the structure of the computing staff. Davis did not have to restructure his computers in order to make them more efficient because he had substantial support from both the navy and Congress. The navy had initially allocated $6,000 a year for the almanac, most of which was spent on the salaries of computers. By the spring of 1850, Davis had concluded that this figure was insufficient, especially with the requirement to prepare two sets of tables. He requested and received $12,000 for the second year of operations. This figure also proved to be too little. For his third year of operations, Davis asked for $18,000.⁵⁰ The navy granted this request, but the increase drew the attention of the U.S. Senate. In May of 1852, Senator John P. Hale (1806–1873) of New Hampshire rose from his desk on the Senate floor and asked the navy to justify its expenditures on the almanac. Though he expressed his concern over the size of the almanac budget, Hale was more interested in a key element of Davis’s plan, the cooperation of naval officers and a civilian computing staff. He might have been less concerned if the computers had been “mere drudges” and could have been drawn from any state of the union. However, he knew that all of Davis’s computers were somehow connected to Benjamin Peirce or Harvard College.⁵¹

Hale demanded that the secretary of the navy “inform the Senate, where, and at what Observatory, the observations and calculations for the ‘Nautical Almanac’ are made.” Like any skilled politician, Hale knew the answer to his question before he strode onto the Senate floor and asked to be recognized. “I think that I am not incorrect,” he informed his colleagues, “when I say that all this expense has been incurred, not at the National Observatory but at the observatory of Cambridge College in Massachusetts.”⁵² “Cambridge College” was, of course, Harvard. He probably misidentified the school as a way of emphasizing its location. If he expected this charge to stir the Senate to action, he was disappointed. Even those who objected to government support for private institutions sat in their seats. Any discussion of the almanac was ended quickly and decisively by a senator who derided Hale as possessing “an absolute and unappeasable hostility to any connections of science with the Naval Department in any form.”⁵³

Though Hale’s comments lasted but a few moments, they pushed Charles Henry Davis to respond. His plans would quickly fail if Congress reduced his budget or dictated the kinds of computers that he might hire. He wrote a detailed defense of his organization, addressed to the secretary of the navy but published in the American Journal of Science and Arts and circulated as a pamphlet. He confronted Hale on the narrow point of the attack, explaining that “no Observatory, neither that at Washington nor that at Cambridge, as has been suggested, received any portion whatever of the sum appropriated for the ‘Nautical Almanac.’” This statement was entirely true, but it did not address the point that many of the computers had a connection to Harvard. Davis tried to deflect this issue by stating that the almanac required the “most illustrious genius and the most exalted talents” and that it was not “a work of insignificant value or trifling labor.” He claimed that the new almanac “is considered by American astronomers and mathematicians as a work of consummate utility and of real national importance, resembling in this respect the Nautical Almanac and Astronomical Ephemeris of Great Britain, the Connaissance des Temps of France and the Astronomical Almanac of Prussia.”⁵⁴

The almanac remained vulnerable to congressional displeasure, even though the crisis initiated by Senator Hale passed quickly. Through the early 1850s, Davis worked to ensure that the almanac offered no target for an easy attack. “In our work there can be no regular vacation,” he advised a new almanac computer. Perhaps sensing that he had overstated his case, he conceded that computing was not a full-time activity and that there were “opportunities for occasional indulgence.”⁵⁵ Without such opportunities, he would have found it difficult to retain his computing staff, as all of them had other interests. Benjamin Peirce requested a reduced computing load so that he might concentrate on mathematics. Maria Mitchell traveled to Europe and relied on her father to communicate with the almanac office.⁵⁶ The most serious threat to almanac operations was the unexpected death of Sears Cook Walker, but Davis was able to recruit Walker’s brother-in-law as a replacement.⁵⁷

The first substantive change in the almanac occurred in 1856, when Davis decided that he must put his naval career ahead of his love for astronomical calculation. In September of that year, the secretary of the navy offered him the command of a ship in the Caribbean. Davis described the order as “an alternative.” He could accept the post and leave the almanac staff; “the other choice was to give up all desire for a command and to resign the active service.”⁵⁸ No matter which choice he made, he had lost control of the almanac, so he accepted the command, gave his office to the senior computer, Joseph Winlock, and departed for the Caribbean.

One of the almanac computers described Joseph Winlock as “silent as General Grant with the ordinary run of men.” He could be friendly and open among the computing staff, but “he had a way of putting his words into exact official form.”⁵⁹ He had no interest in changing the operations of the almanac but was content to follow the computing plans of Charles Henry Davis and the advice of the ever-present Benjamin Peirce. His only step toward innovation involved the almanac in a controversy at the newly formed Dudley Observatory in Albany, New York. That observatory had acquired a difference engine, though it was not the engine that had been designed by Charles Babbage and had never been completed. This engine was a smaller machine that had been built by two Swedes, George Scheutz (1785–1873) and his son Edvard (1821–1888). The elder Scheutz had read about the Babbage difference engine in a newspaper and had built a simple model with Edvard. The younger Scheutz had created engineering drawings and found a machine shop that would build the engine. Their design drew on the technology of clocks, while Babbage had borrowed the tools and ideas of steam engines. The Scheutz engine looked like a large music box and could sit on a desk or a dining table. Recognizing that this machine was an improvement of his ideas, Babbage praised the Scheutz design as “highly deserving of a Medal.”⁶⁰

11. Scheutz difference engine used by the computers of the Nautical Almanac

The Scheutz difference engine had reached the United States because of the efforts of Dudley Observatory director Benjamin Gould (1824–1896). Gould was yet another student of Benjamin Peirce. He had discovered the difference engine while traveling in Europe and had been impressed with its potential. He claimed that it might change the nature of observatory staffs by replacing “the toiling brain by mere muscular force.”⁶¹ He had no immediate use for the engine and was willing to let the almanac staff experiment with the device. Joseph Winlock thought that it might be able to prepare certain tables for the almanac. He sent two computers on a trip from Boston to Albany with the instructions to prepare an ephemeris for Mars. When the computers arrived at the Dudley Observatory, they found that the machine was inoperable. “The dirt, which had accumulated on the passage [across the Atlantic], and thickened oil, impeded its action greatly.” A mechanic cleaned the machine and returned it to operating condition, allowing the computers to start their work.⁶² The calculations proved to be more difficult than anyone had anticipated. The computers discovered that the Scheutz machine was fragile and sensitive. It could easily jam in the middle of a calculation, a problem which could require a lengthy repair effort and force the computers to restart their calculations from the beginning.⁶³

After a month of work, the computers returned to Boston with two intermediate tables but without a complete ephemeris. They had discovered that the difference engine could calculate only small segments of tables. If the orbit of Mars were placed on a clock dial, the machine could compute the arc between noon and eleven o’clock before it needed to be reset. “The strictly algebraical problems for feeding the machine made quite as heavy demands upon time, and thought, and perseverance, as did the problem of regulating its mechanical action,”⁶⁴ observed Benjamin Gould. In reviewing the tables, Winlock expressed his hope “that the immense labor of astronomical calculations may be materially diminished by the aid of machinery,” but he was disappointed.⁶⁵ “The result thus far has not been such as to demonstrate to my satisfaction that any considerable portion of the Almanac can be computed more economically by this machine.”⁶⁶ The failure of this experiment had more impact in Albany than in Washington. Benjamin Gould had become involved in a fight with observatory trustees over several key decisions, including the purchase of the difference engine. “The responsibility of having recommended this machine I willingly accept,” wrote Gould. “If the machine has not multiplied and tabulated [the donor’s] fame to an amount equal to the wishes of [his] most ardent friends,” he added, “it has not been my fault.”⁶⁷

Compared to the other issues facing the almanac office, the failure of the difference engine experiment was only a minor problem for Winlock. The almanac computers had fallen behind schedule. The almanac budget had been reduced by Congress. At the start of 1859, Winlock had been forced to release part of his computing staff and stop work on some of the ephemerides.⁶⁸ The trouble ended only with the return of Charles Henry Davis that summer. Davis reported “that several parts of the work were omitted or postponed; that printing had been arrested or delayed, and the efficiency of the corps of computers diminished.”⁶⁹ He quickly brought the computers back to their production schedule and convinced Congress to restore the almanac budget. In less than a year, he could report that “the regular work of the office was resumed with more than common activity.”⁷⁰

Of course, the fall of 1860 was no common time. The changing political climate could only remind Davis that the scientific activity of the Nautical Almanac Office was held most firmly in the grip of forces beyond the ability of any one person to control. By December, the goal of preparing a high-quality almanac seemed less important than the need to preserve the country’s social structure. Following the election of Abraham Lincoln in November, the country had reached a point of crisis on the question of slavery, and the Southern states were preparing to secede. Southern naval officers, including the director of the Naval Observatory, resigned their commissions and returned home.⁷¹ Charles Henry Davis was summoned to Washington and discovered that he would have little time to think about the operations of the almanac. “I have found that [the director of the Coast Survey] has a plan of his own to carry out, which involves my remaining here,” he explained to his family. “[The director] wishes to establish a military commission, or advisory council, to determine military proceedings and operations along the coast.”⁷²

Through the spring and summer of 1861, Davis tried to manage the almanac computers while simultaneously organizing surveying units for both the navy and army. He spent most of his days at the Coast Survey building. The survey office was located just south of the Capitol. Its top floors had a view of the navy yard, the Washington arsenal, and the Confederate volunteers of Virginia holding positions on the far side of the Potomac River. The sights and sounds and rumors troubled him so much that he complained, “The more I hear, the more I fear for the end.” He poured out his sadness, his anxiety, and his guilt by invoking Shakespeare’s murderous lord: “Like Macbeth, I’m sick at heart (‘Seyton, I say!’).”⁷³

The words of Macbeth came freely from his pen that summer. If taken literally, Davis cast himself as the title character, the military leader who had been misled by his own ambitions, had killed his king, and had pushed his country into chaos. Increasingly, the almanac director felt that he was needed elsewhere. “My hands are not of much use in working,” he told his family, “but my head might be in directing.”⁷⁴ In September, he concluded that he needed to be released from the institution that he had built and led for a decade. “Today I give up the ‘Nautical Almanac,’” Davis wrote. “I am very sorry to do it, but I could not retain it.” He would have to trust his hopes and plans for the almanac to others. “Winlock takes my place,” he acknowledged, “and he will be glad to get it.”⁷⁵ Though Davis was generally not given to ironic comments, he does not seem to be blessing his successor. An era was ending, and the early computers, the “gentlemen of liberal education,” would soon depart, to be replaced with more traditional computers. Benjamin Peirce had already left the almanac. The others would soon follow. Even Maria Mitchell had only a short time remaining. She would shortly be appointed the first professor of astronomy at Vassar College for Women.