Longitude Dava Sobel Quotes

He wrested the world's whereabouts from the stars, and locked the secret in a pocket watch.

One degree of longitude equals four minutes of time the world over, but in terms of distance, one degree shrinks from sixty-eight miles at the Equator to virtually nothing at the poles.

[John] Harrison [could not] express himself clearly in writing.... No matter how brilliantly ideas formed in his mind, or crystallized in his clockworks, his verbal descriptions failed to shine with the same light.... The first sentence [of his last published work] runs on, virtually unpunctuated, for twenty-five pages." Dava Sobel, Longitude, p66

With his marine clocks, John Harrison tested the waters of space-time. He succeeded, against all odds, in using the fourth—temporal—dimension to link points on the three-dimensional globe. He wrested the world’s whereabouts from the stars, and locked the secret in a pocket watch.

The zero-degree parallel of latitude is fixed by the laws of nature, while the zero-degree meridian of longitude shifts like the sands of time.

In the wake of the Longitude Act, the concept of “discovering the longitude” became a synonym for attempting the impossible.

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. Even when the bulbs of the hourglass shatter, when darkness withholds the shadow from the sundial, when the mainspring winds down so far that the clock hands hold still as death, time itself keeps on. The most we can hope a watch to do is mark that progress. And since time sets its own tempo, like a heartbeat or an ebb tide, timepieces don't really keep time. They just keep up with it, if they're able.

Any clock that can track this sideral schedule proves itself as perfect as God's magnificent clockwork. Dava Sobel

He wrested the world’s whereabouts from the stars, and locked the secret in a pocket watch.

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.

The zero-degree parallel of latitude is fixed by the laws of nature, while the zero-degree meridian of longitude shifts like the sands of time. This difference makes finding latitude child’s play, and turns the determination of longitude, especially at sea, into an adult dilemma—one that stumped the wisest minds of the world for the better part of human history.

Earlier maps had underestimated the distances to other continents and exaggerated the outlines of individual nations. Now global dimensions could be set, with authority, by the celestial spheres. Indeed, King Louis XIV of France, confronted with a revised map of his domain based on accurate longitude measurements, reportedly complained that he was losing more territory to his astronomers than to his enemies.

Having established itself securely on shipboard, the chronometer was soon taken for granted, like any other essential thing, and the whole question of its contentious history, along with the name of its original inventor, dropped from the consciousness of the seamen who used it every day.

Today, the latitude and longitude lines govern with more authority than I could have imagined forty-odd years ago, for they stay fixed as the world changes its configuration underneath them—with continents adrift across a widening sea, and national boundaries repeatedly redrawn by war or peace.

To learn one’s longitude at sea, one needs to know what time it is aboard ship and also the time at the home port or another place of known longitude—at that very same moment. The two clock times enable the navigator to convert the hour difference into a geographical separation. Since the Earth takes twenty-four hours to complete one full revolution of three hundred sixty degrees, one hour marks one twenty-fourth of a spin, or fifteen degrees.

Indeed, King Louis XIV of France, confronted with a revised map of his domain based on accurate longitude measurements, reportedly complained that he was losing more territory to his astronomers than to his enemies.

In 1884, at the International Meridian Conference held in Washington, D.C., representatives from twenty-six countries voted to make the common practice official. They declared the Greenwich meridian the prime meridian of the world. This decision did not sit well with the French, however, who continued to recognize their own Paris Observatory meridian, a little more than two degrees east of Greenwich, as the starting line for another twenty-seven years, until 1911. (Even then, they hesitated to refer directly to Greenwich mean time, preferring the locution “Paris Mean Time, retarded by nine minutes twenty-one seconds.”)

the beaches. In literally hundreds of instances, a vessel’s ignorance of her longitude led swiftly to her destruction. 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 captain would throw a log overboard and observe how quickly the ship receded from this temporary guidepost. He noted the crude speedometer reading in his ship’s logbook, along with the direction of travel, which he took from the stars or a compass, and the length of time on a particular course, counted with a sandglass or a pocket watch. Factoring in the effects of ocean currents, fickle winds, and errors in judgment, he then determined his longitude. He routinely missed his mark, of course—searching

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. He kept it all under seal at Greenwich.

How sour sweet music is When time is broke and no proportion kept!

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. Even when the bulbs of the hourglass shatter, when darkness withholds the shadow from the sundial, when the mainspring winds down so far that the clock hands hold still as death, time itself keeps on.

Today, the latitude and longitude lines govern with more authority than I could have imagined forty-odd years ago, for they stay fixed as the world changes it’s configuration underneath them—with continents adrift across a widening sea, the national boundaries repeatedly redrawn by war or peace.

Christopher Wren, architect of St. Paul’s Cathedral.

(Multiplying a difference in hours by fifteen degrees gives only an approximation of location; one also needs to divide the number of minutes and seconds by four, to convert the time readings to degrees and minutes of arc.) Nor had timepieces enjoyed any significant advances by 1622, when English navigator Thomas Blundeville proposed using “some true Horologie or Watch” to determine longitude on transoceanic voyages.

Huygens, best known as the first great horologist, swore he arrived at the idea for the pendulum clock independently of Galileo. And indeed he evinced a deeper understanding of the physics of pendulum swings—and the problem of keeping them going at a constant rate—when he built his first pendulum-regulated clock in 1656. Two years later Huygens published a treatise on its principles, called the Horologium, in which he declared his clock a fit instrument for establishing longitude at sea. By 1660, Huygens had completed not one but two marine timekeepers based on his principles.

Surely one of the most astute, succinct dismissals of fellow hopefuls came from the pen of Jeremy Thacker of Beverly, England. Having heard the half-baked bids to find longitude in the sound of cannon blasts, in compass needles heated by fire, in the moon’s motion, in the sun’s elevation, and what-else-have-you, Thacker developed a new clock ensconced in a vacuum chamber and declared it the best method of all: “In a word, I am satisfied that my Reader begins to think that the Phonometers, Pyrometers, Selenometers, Heliometers, and all the Meters are not worthy to be compared with my Chronometer.

Thacker’s witty neologism is apparently the first coinage of the word chronometer. What he said in 1714, perhaps in jest, later gained acceptance as the perfect moniker for the marine timekeeper. We still call such a device a chronometer today. Thacker’s chronometer, however, was not quite as good as its name.

The measurement of longitude meridians, in comparison, is tempered by time. To learn one’s longitude at sea, one needs to know what time it is aboard ship and also the time at the home port or another place of known longitude—at that very same moment. The two clock times enable the navigator to convert the hour difference into a geographical separation. Since the Earth takes twenty-four hours to complete one full revolution of three hundred sixty degrees, one hour marks one twenty-fourth of a spin, or fifteen degrees. And so each hour’s time difference between the ship and the starting point marks a progress of fifteen degrees of longitude to the east or west. Every day at sea, when the navigator resets his ship’s clock to local noon when the sun reaches its highest point in the sky, and then consults the home-port clock, every hour’s discrepancy between them translates into another fifteen degrees of longitude.

Уверяют, будто Людовик XIV, увидев новые карты своих владений, основанные на точном определении долготы, посетовал, что геодезисты отняли у него больше земель, чем неприятель.

Lying in state now in an exhibit case at London’s National Maritime Museum, H-4 draws millions of visitors a year. Most tourists approach the Watch after having passed the cases containing H-1, H-2, and H-3. Adults and youngsters alike stand mesmerized before the big sea clocks. They move their heads to follow the swinging balances, which rock like metronomes on H-1 and H-2. They breathe in time to the regular rhythm of the ticking, and they gasp when startled by the sudden, sporadic spinning of the single-blade fan that protrudes from the bottom of H-2. But H-4 stops them cold. It purports to be the end of some orderly progression of thought and effort, yet it constitutes a complete non sequitur. What’s more, it holds still, in stark contrast to the whirring of the going clocks. Not only are its mechanisms hidden by the silver case enclosure, but the hands are frozen in time. Even the second hand lies motionless. H-4 does not run. It could run, if curators would allow it to, but they demur, on the grounds that H-4 enjoys something of the status of a sacred relic or a priceless work of art that must be preserved for posterity. To run it would be to ruin it.

The active quest for a solution to the problem of longitude persisted over four centuries and across the whole continent of Europe. Most crowned heads of state eventually played a part in the longitude story, notably King George III of England and King Louis XIV of France.

In the course of their struggle to find longitude, scientists struck upon other discoveries that changed their view of the universe. These include the first accurate determinations of the weight of the Earth, the distance to the stars, and the speed of light.

After the fractious second trial of the Watch in the summer of 1764, the Board of Longitude allowed months to pass without saying a word. The commissioners were waiting for the mathematicians to compare their computations of H-4’s performance with the astronomers’ observations of the longitude of Portsmouth and Barbados, all of which had to be factored into the judging. When they heard the final report, the commissioners conceded that they were “unanimously of opinion that the said timekeeper has kept its time with sufficient correctness.” They could hardly say otherwise: The Watch proved to tell the longitude within ten miles—three times more accurately than the terms of the Longitude Act demanded! But this stupendous success gained Harrison only a small victory. The Watch and its maker still had lots of explaining to do.

The painting now hangs in the gallery at the Old Royal Observatory. It shows Harrison as a man to be reckoned with. Dressed in a chocolate brown frock coat and britches, he sits surrounded by his inventions, including H-3 at his right and the precision gridiron-pendulum regulator, which he built to rate his other timepieces, behind him. Even seated he assumes an erect bearing and a look of self-satisfied, but not smug, accomplishment. He wears a gentleman’s white wig and has the clearest, smoothest skin imaginable. (The story of Harrison’s becoming fascinated with watch-works in childhood, while recuperating from an illness, holds that he suffered a severe case of smallpox at the time. We must conclude, however, that the tale is tall, or that he experienced a miraculous recovery, or that the artist has painted out the scars.)

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.

Halley had become England’s second astronomer royal in 1720, after John Flamsteed’s death. The puritanical Flamsteed had reason to roll over in his grave at this development, since in life he had denounced Halley for drinking brandy and swearing “like a sea-captain.” And of course Flamsteed never forgave Halley, or his accomplice Newton, for pilfering the star catalogs and publishing them against his will. Well liked by most, kind to his inferiors, Halley ran the observatory with a sense of humor. He added immeasurably to the luster of the place with his observations of the moon and his discovery of the proper motion of the stars—even if it’s true what they say about the night he and Peter the Great cavorted like a couple of schoolboys and took turns pushing each other through hedges in a wheelbarrow.

One [method] is by a Watch to keep time exactly. But, by reason of the motion of the Ship, the Variation of Heat and Cold, Wet and Dry, and the Difference of Gravity in different Latitudes, such a watch hath not yet been made.” And not likely to be, either, he implied.

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. Even when the bulbs of the hour glass shatter, when darkness withholds the shadow from the sundial, when the main spring winds down so far that the clock hands hold still as death, time itself keeps on. The most we can hope for a watch to do is mark that progress. And since time sets its own tempo, like a heartbeat or an ebb tide, time pieces don't really keep time. They just keep up with it, if they're able.

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. He kept it all under seal at Greenwich. Newton and Halley managed to get hold of most of Flamsteed’s records from the Royal Observatory, and published their own pirated edition of his star catalog in 1712. Flamsteed retaliated by collecting three hundred of the four hundred printed copies, and burning them.

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.

John “Longitude” Harrison was born March 24, 1693, in the county of Yorkshire, the eldest of five children.

Halley had become England’s second astronomer royal in 1720, after John Flamsteed’s death. The puritanical Flamsteed had reason to roll over in his grave at this development, since in life he had denounced Halley for drinking brandy and swearing “like a sea-captain.” And of course Flamsteed never forgave Halley, or his accomplice Newton, for pilfering the star catalogs and publishing them against his will.

Harrison, now a London resident and forty-eight years old, faded into his workshop and was hardly heard from during the nearly twenty years he devoted to the completion of H-3, which he called his “curious third machine.

This decision did not sit well with the French, however, who continued to recognize their own Paris Observatory meridian, a little more than two degrees east of Greenwich, as the starting line for another twenty-seven years, until 1911. (Even then, they hesitated to refer directly to Greenwich mean time, preferring the locution “Paris Mean Time, retarded by nine minutes twenty-one seconds.”)