Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of his Time

by Dava Sobel

After leaving the museum I walked across the street, through the park, and up the hill to Flamsteed House, the observatory designed by Sir Christopher Wren in 1675. King Charles II had ordered the observatory to be built to improve marine navigation and “find out the so-much desired longitude at sea for perfecting the art of navigation.”

The observatory is the location of the prime meridian. An imaginary plane passing through the observatory and through the Earth's north and south poles will cleave Earth precisely into eastern and western hemispheres. The observatory also serves as the base for Greenwich mean time (GMT) and hence is the location where each day, year, and century begins.

At some point, Harrison's chronometers were moved from the museum, across the street, through the park, and up the hill to the observatory. It is ironic that the clocks, at the time of this writing, should reside in the laboratory of the clock's greatest critics, the astronomers.

Pope Alexander VI issued the Bull of Demarcation in settlement. With aloof equanimity, His Holiness drew a meridian line from north to south on a chart of the great ocean, one hundred leagues west of the Azores. He assigned all lands west of the line, discovered or undiscovered, to Spain and all lands east of it to Portugal. It was masterful diplomacy, particularly when no one knew where the line fell.

consequence, untold numbers of sailors died when their destinations suddenly loomed out of the sea and took them by surprise. In a single such accident, on October 22, 1707, at the Scilly Isles near the southwestern tip of England, four homebound British warships ran aground and nearly two thousand men lost their lives.

As time passed and no method proved successful, the search for a solution to the longitude problem assumed legendary proportions, on a par with discovering the Fountain of Youth, the secret of perpetual motion, or the formula for transforming lead into gold. The governments of the great maritime nations— including Spain, the Netherlands, and certain city-states of Italy—periodically roiled the fervor by offering jackpot purses for a workable method. The British Parliament, in its famed Longitude Act of 1714, set the highest bounty of all, naming a prize equal to a king’s ransom (several million dollars in today’s currency) for a “Practicable and Useful” means of determining longitude.

With no formal education or apprenticeship to any watchmaker, Harrison nevertheless constructed a series of virtually friction-free clocks that required no lubrication and no cleaning, that were made from materials impervious to rust, and that kept their moving parts perfectly balanced in relation to one another, regardless of how the world pitched or tossed about them.

Certainly he had time to reflect on the events of the previous twenty-four hours, when he made what must have been the worst mistake in judgment of his naval career. He had been approached by a sailor, a member of the Association’s crew, who claimed to have kept his own reckoning of the fleet’s location during the whole cloudy passage. Such subversive navigation by an inferior was forbidden in the Royal Navy, as the unnamed seaman well knew. However, the danger appeared so enormous, by his calculations, that he risked his neck to make his concerns known to the officers. Admiral Shovell had the man hanged for mutiny on the spot.

Launched on a mix of bravery and greed, the sea captains of the fifteenth, sixteenth, and seventeenth centuries relied on “dead reckoning” to gauge their distance east or west of home port.

The main problem with this “lunar distance method” was that the positions of the stars, on which the whole process depended, were not at all well known. Then, too, no astronomer could predict exactly where the moon would be from one night or day to the next, since the laws that governed the moon’s motion still defied detailed understanding. And besides, sailors had no accurate instruments for measuring moon-to-star distances from a rolling ship. The idea was way ahead of its time. The quest for another cosmic time cue continued.

In spite of these obvious difficulties, Galileo had designed a special navigation helmet for finding longitude with the Jovian satellites. The headgear—the celatone—has been compared to a brass gas mask in appearance, with a telescope attached to one of the eyeholes. Through the empty eyehole, the observer’s naked eye could locate the steady light of Jupiter in the sky. The telescope afforded the other eye a look at the planet’s moons.

Galileo’s method for finding longitude at last became generally accepted after 1650—but only on land. Surveyors and cartographers used Galileo’s technique to redraw the world. And it was in the arena of mapmaking that the ability to determine longitude won its first great victory.

Greater precision in the timing of these events would permit greater exactitude in charting. With the borders of kingdoms hanging in the balance, numerous astronomers found gainful employment observing the moons and improving the accuracy of the printed tables. In 1668, Giovanni Domenico Cassini, a professor of astronomy at the University of Bologna, published the best set yet, based on the most numerous and most carefully conducted observations.

Louis XIV, despite any disgruntlement about his diminishing domain, showed a soft spot for science. He had given his blessing to the founding, in 1666, of the French Académie Royale des Sciences, the brainchild of his chief minister, Jean Colbert. Also at Colbert’s urging, and under the ever-increasing pressure to solve the longitude problem, King Louis approved the building of an astronomical observatory in Paris.

Until this realization, light was thought to get from place to place in a twinkling, with no finite velocity that could be measured by man. Roemer now recognized that earlier attempts to clock the speed of light had failed because the distances tested were too short. Galileo, for example, had tried in vain to time a light signal traveling from a lantern on one Italian hilltop to an observer on another. He never detected any difference in speed, no matter how far apart the hills he and his assistants climbed. But in Roemer’s present, albeit inadvertent, experiment, Earthbound astronomers were watching for the light of a moon to reemerge from the shadow of another world.

Thus the founding philosophy of the Royal Observatory, like that of the Paris Observatory before it, viewed astronomy as a means to an end. All the far-flung stars must be cataloged, so as to chart a course for sailors over the oceans of the Earth.

This book packs a punch A lot of really interesting historical science information in a very short number of pages Loving that

Time is to clock as mind is to brain. The clock or watch somehow contains the time. And yet time refuses to be bottled up like a genie stuffed in a lamp. Whether it flows as sand or turns on wheels within wheels, time escapes irretrievably, while we watch.

Quote flash Really interesting

The two conditions that Frisius spelled out, however— namely, that the clock be set to the hour of departure with “the greatest exactness” and that it not be allowed to run down during the voyage—virtually ruled out any chance of applying the method at that time. The clocks of the early sixteenth century weren’t equal to the task. They were neither accurate nor able to run true against the assault of changing temperature on the high seas.

Galileo, who, as a young medical student, successfully applied a pendulum to the problem of taking pulses, late in life hatched plans for the first pendulum clock. In June of 1637, according to Galileo’s protégé and biographer, Vincenzo Viviani, the great man described his idea for adapting the pendulum “to clocks with wheelwork for assisting the navigator to determine his longitude.”

However, the distinction for completing the first working pendulum clock fell to Galileo’s intellectual heir, Christiaan Huygens, the landed son of a Dutch diplomat who made science his life.

Huygens also discovered Saturn’s largest moon, which he named Titan, and was the first to notice markings on Mars. But Huygens couldn’t be tied to the telescope all the time. He had too many other things on his mind. It is even said that he chided Cassini, his boss at the Paris Observatory, for the director’s slavish devotion to daily observing.

By 1660, Huygens had completed not one but two marine timekeepers based on his principles. He tested them carefully over the next several years, sending them off with cooperative sea captains. On the third such trial, in 1664, Huygens’s clocks sailed to the Cape Verde Islands, in the North Atlantic off the west coast of Africa, and kept good track of the ship’s longitude all the way there and back.

The Hooke-Huygens conflict over the right to an English patent for the spiral balance spring disrupted several meetings of the Royal Society, and eventually the matter was dropped from the minutes, without being decided to either contestant’s satisfaction.

A chart could be drawn—and many were—linking longitude to the observable distance between magnetic north and true north. This so-called magnetic variation method had one distinct advantage over all the astronomical approaches: It did not depend on knowing the time at two places at once or knowing when a predicted event would occur.

What’s more, the results were further contaminated by the vagaries of terrestrial magnetism, the strength of which waxed or waned with time in different regions of the seas, as Edmond Halley found during a two-year voyage of observation.

Even on a clear night, however, Fyler’s approach invoked more astronomical data than existed in all the world’s observatories, and its reasoning was as circular as the celestial sphere.

Scilly Isles

Newton prepared written remarks for the committee members, which he read aloud to them, and also answered their questions, despite his “mental fatigue” that day. He summarized the existing means for determining longitude, saying that all of them were true in theory but “difficult to execute.”

The Longitude Act established a blue ribbon panel of judges that became known as the Board of Longitude. This board, which consisted of scientists, naval officers, and government officials, exercised discretion over the distribution of the prize money.

This is so cool Do we have any prizes like this today?

Part of the sport of tackling the longitude problem entailed ridiculing others in the competition. A pamphleteer who signed himself “R.B.” said of Mr. Whiston, the fireball proponent, “[I]f he has any such Thing as Brains, they are really crackt.”

lol compliment today

Room temperature exerted a powerful influence on the going rate of any timekeeper. Metal pendulum rods expanded with heat, contracted when cooled, and beat out seconds at different tempos, depending on the temperature. Similarly,

Thacker had considered this problem at great length when testing his chronometer. In fact, the proposal he submitted to the longitude board contained his careful records of the chronometer’s rate at various temperature readings, along with a sliding scale showing the range of error that could be expected at different temperatures. A mariner using the chronometer would simply have to weigh the time shown on the clock’s dial against the height of the mercury in the thermometer tube, and make the necessary calculations. This is where the plan falls apart: Someone would have to keep constant watch over the chronometer, noting all changes in ambient temperature and figuring them into the longitude reading.

Six seconds sound like nothing compared to the fifteen minutes routinely lost by earlier clocks. Why split hairs? Because of the consequences—and the money— involved. To prove worthy of the £20,000 prize, a clock had to find longitude within half a degree.

Very cool that this is so precise and quantitative

Newton grew impatient. It was clear to him now that any hope of settling the longitude matter lay in the stars. The lunar distance method that had been proposed several times over preceding centuries gained credence and adherents as the science of astronomy improved. Thanks to Newton’s own efforts in formulating the Universal Law of Gravitation, the moon’s motion was better understood and to some extent predictable. Yet the world was still waiting on Flamsteed to finish surveying the stars. Flamsteed, meticulous to a fault, had spent forty years mapping the heavens—and had still not released his data.

lol like some scientists today never publishing Scientists need to ship!

“I committed them to the fire about a fortnight ago,” Flamsteed wrote to his former observing assistant Abraham Sharp. “If Sir I. N. would be sensible of it, I have done both him and Dr. Halley a very great kindness.” In other words, the published positions, insufficiently verified as they were, could only discredit a respectable astronomer’s reputation.

Newton died in 1727, and therefore did not live to see the great longitude prize awarded at last, four decades later, to the self-educated maker of an oversized pocket watch.

For instance, Harrison educated himself with the same hunger for knowledge that kept young Abraham Lincoln reading through the night by candlelight.

His family, in keeping with the custom of the time, dealt out names so parsimoniously that it is impossible to keep track of all the Henrys, Johns, and Elizabeths without pencil and paper. To wit, John Harrison served as the son, grandson, brother, and uncle of one Henry Harrison or another, while his mother, his sister, both his wives, his only daughter, and two of his three daughters-in-law all answered to the name Elizabeth.

Although John Harrison forswore Shakespeare, never allowing the Bard’s works in his house, Newton’s Principia and Saunderson’s lectures stood him in good stead for the rest of his life, strengthening his own firm grasp on the natural world. Harrison

Aside from the fact that the great John Harrison built it, the clock claims uniqueness for another singular feature: It is constructed almost entirely of wood. This is a carpenter’s clock, with oak wheels and boxwood axles connected and impelled by small amounts of brass and steel. Harrison, ever practical and resourceful, took what materials came to hand, and handled them well.

No known clockmaker, other than self-taught Harrison himself, lived or worked anywhere around north Lincolnshire in the early eighteenth century.

Harrison, according to those who admired him most, never could express himself clearly in writing. He wrote with the scrivener’s equivalent of marbles in the mouth. No matter how brilliantly ideas formed in his mind, or crystallized in his clockworks, his verbal descriptions failed to shine with the same light.

His last published work, which outlines the whole history of his unsavory dealings with the Board of Longitude, brings his style of endless circumlocution to its peak. The first sentence runs on, virtually unpunctuated, for twenty-five pages.

lol

At the start of their fifty years together they had two children—William, born in 1728, who was to become his father’s champion and right-hand man, and Elizabeth, born in 1732, about whom nothing is known save the date of her baptism, December 21.

and that there’s no good way to get rid of nuclear waste.

Sad that this was used as an example in the 90s

From its fine cabinet to its friction-free gearing, the clock reveals its maker as a master carpenter. For example, the works run without oil. The clock never needs lubrication, because the parts that would normally call for it were carved out of lignum vitae, a tropical hardwood that exudes its own grease.

A clock without oil, which till then was absolutely unheard of, would stand a much better chance of keeping time at sea than any clock yet built. For lubricants got thicker or thinner as temperatures dipped or soared over the course of a voyage, making the clock run faster or slower as a result— or cease running altogether.

Judging from recorded acts of John’s generosity later in life, it appears that he gave his kid brother a boost by letting him put his own stamp on their joint venture.

Good to be generous with credit for things, ultimately makes you look good

From one night to the next, because of the Earth’s rotation, a star should transit exactly 3 minutes, 56 seconds (of solar time) earlier than the previous night. Any clock that can track this sidereal schedule proves itself as perfect as God’s magnificent clockwork. In these late-night tests, the Harrisons’ clocks never erred more than a single second in a whole month.