In
consecutive monthly episodes we will tell you the story of the missing
link discovered by John Harrison when he invented the timekeeper during the
second half of the eighteenth century.
He gave seamen the mastery of longitude and accurate access to the planet earth third dimension. The gate to the timeless fourth dimension was then opened for the maritime discoverers.
Our narrative will use extensively excerpts of the Dava Sobel's "Illustrated Longitude" first published in Great Britain in 1998.
To know more about the author or the book, go to: http://www.sailtexas.com/long.html
He gave seamen the mastery of longitude and accurate access to the planet earth third dimension. The gate to the timeless fourth dimension was then opened for the maritime discoverers.
Our narrative will use extensively excerpts of the Dava Sobel's "Illustrated Longitude" first published in Great Britain in 1998.
To know more about the author or the book, go to: http://www.sailtexas.com/long.html
CHAPTER
ONE: IMAGINARY LINES
"When I am playful I use the meridians of longitude and parallels of latitude for a seine, and drag the Atlantic Ocean for whales." Mark Twain, Life on the Mississippi.
Lines of latitude and longitude began crisscrossing our worldview in ancient times, at least three centuries before the birth of Christ. By A.D. 150, the cartographer and astronomer Ptolemy had plotted them on the twenty-seven maps of his first world atlas. Ptolemy listed all the place names in an index, in alphabetical order, with the latitude and longitude of each - as well as he could gauge them from travellers' reports. Ptolemy himself had only an armchair appreciation of the wider world. A common misconception of his day held that anyone living below the Equator would melt into deformity from the horrible heat.
The Equator marked the zero degree parallel of latitude for Ptolemy. He did not choose it arbitrarily but took it on higher authority from his predecessors, who had derived it from nature while observing the motions of the heavenly bodies.
Ptolemy was free, however, to lay his prime meridian, the zero degree longitude line, wherever he liked. He chose to run it through the Fortunate Islands (now called the Canary Islands).
Here lies the real, hard-core difference between latitude and longitude - beyond the superficial difference in line direction that any child can see: 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.
Any sailor worth his salt can gauge his latitude well enough by the length of the day, or by the height of the sun or known guide stars above the horizon. Christopher Columbus followed a straight path across the Atlantic when he "sailed the parallel" on his 1492 Journey. The measurement of longitude meridians, in comparison, is tempered by time. To learn one's longitude at sea, one need to know what time it is aboard ship and also the time at the homeport 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.
Precise knowledge of the hour in two different places at once was utterly unattainable up to and including the era of pendulum clocks. On the deck of a rolling ship, such clocks would slow down, or speed up, or stop running altogether. Normal changes in temperature encountered en route from a cold country of origin to a tropical trade zone thinned or thickened a clock's lubricating oil and made its metal parts expand or contract with equally disastrous results. A rise or fall in barometric pressure, or the subtle variations in the Earth's gravity from one latitude to another, could also cause a clock to gain or lose time.
For lack of a practical method of determining longitude, every great captain in the Age of Exploration became lost at sea despite the best available charts and compasses. From Vasco de Gama to Vasco Nunez de Balboa, from Magellan to Sir Francis Drake, they all got where they were going willy-nilly, by forces attributed to good luck or the grace of God.
The wealth of nations floated upon the oceans, and still no ship owned a reliable means for establishing her whereabouts. In consequence untold numbers of sailors died when their destinations suddenly loomed out of the sea and took them by surprise.
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 George III and Louis XIV. Seafaring men such as Captain Bligh of the Bounty and Captain James Cook took the more promising methods at sea to test their accuracy and practicability.
Renowned astronomers approached the longitude challenge by appealing to the clockwork universe. Palatial observatories were founded in Paris, London and Berlin for the express purpose of determining longitude by the heavens.
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 determination of the weight of the Earth, the distance to the stars, and the speed of light.
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 periodically roiled the fervour 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 for a "Practicable and Useful" means of determining longitude.
English clockmaker John Harrison, a mechanical genius who pioneered the science of portable precision timekeeping, devoted his life to this quest. He accomplished what Newton had feared was impossible: He invented a clock that would carry the true time from the homeport, like an eternal flame, to any remote corner of the world.
Harrison, a man of simple birth and high intelligence, crossed swords with the leading lights of his day. He made a special enemy of the Reverend Nevil Maskelyne, the fifth astronomer royal, who contested his claim to the coveted prize money, and whose tactics at certain junctures can only be described as foul play.
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. He did away with the pendulum, and he combined different metals inside his works in such a way that when one component expanded or contracted with changes in temperature, the other counteracted the change and kept the clock's rate constant.
Members of the scientific elite, who distrusted Harrison's magic box, however, parried his every success. The commissioners charged with awarding the longitude prize - Nevil Maskelyne among them - changed the contest rules wherever they saw fit, so as to favor the chances of astronomers over the likes of Harrison and his fellow "mechanics". But the utility and accuracy of Harrison's approach triumphed in the end. His followers shepherded Harrison's intricate, exquisite invention through the design modifications that enabled it to be massed produced and enjoy wide use.
An aged, exhausted Harrison, taken under the wing of King George III, ultimately claimed his rightful monetary reward in 1773 - after forty struggling years of political intrigue, international warfare, academic backbiting, scientific revolution, and economic upheaval.
All these threads, and more, entwine in the lines of longitude. To unravel them now - to retrace their story in an age when a network of orbiting satellites can nail down a ship's position within a few feet in just a moment or two - is to see the globe anew.
In our coming February episode, you will be told some of the extraordinary tales of the sea before time.
"When I am playful I use the meridians of longitude and parallels of latitude for a seine, and drag the Atlantic Ocean for whales." Mark Twain, Life on the Mississippi.
Lines of latitude and longitude began crisscrossing our worldview in ancient times, at least three centuries before the birth of Christ. By A.D. 150, the cartographer and astronomer Ptolemy had plotted them on the twenty-seven maps of his first world atlas. Ptolemy listed all the place names in an index, in alphabetical order, with the latitude and longitude of each - as well as he could gauge them from travellers' reports. Ptolemy himself had only an armchair appreciation of the wider world. A common misconception of his day held that anyone living below the Equator would melt into deformity from the horrible heat.
The Equator marked the zero degree parallel of latitude for Ptolemy. He did not choose it arbitrarily but took it on higher authority from his predecessors, who had derived it from nature while observing the motions of the heavenly bodies.
Ptolemy was free, however, to lay his prime meridian, the zero degree longitude line, wherever he liked. He chose to run it through the Fortunate Islands (now called the Canary Islands).
Here lies the real, hard-core difference between latitude and longitude - beyond the superficial difference in line direction that any child can see: 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.
Any sailor worth his salt can gauge his latitude well enough by the length of the day, or by the height of the sun or known guide stars above the horizon. Christopher Columbus followed a straight path across the Atlantic when he "sailed the parallel" on his 1492 Journey. The measurement of longitude meridians, in comparison, is tempered by time. To learn one's longitude at sea, one need to know what time it is aboard ship and also the time at the homeport 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.
Precise knowledge of the hour in two different places at once was utterly unattainable up to and including the era of pendulum clocks. On the deck of a rolling ship, such clocks would slow down, or speed up, or stop running altogether. Normal changes in temperature encountered en route from a cold country of origin to a tropical trade zone thinned or thickened a clock's lubricating oil and made its metal parts expand or contract with equally disastrous results. A rise or fall in barometric pressure, or the subtle variations in the Earth's gravity from one latitude to another, could also cause a clock to gain or lose time.
For lack of a practical method of determining longitude, every great captain in the Age of Exploration became lost at sea despite the best available charts and compasses. From Vasco de Gama to Vasco Nunez de Balboa, from Magellan to Sir Francis Drake, they all got where they were going willy-nilly, by forces attributed to good luck or the grace of God.
The wealth of nations floated upon the oceans, and still no ship owned a reliable means for establishing her whereabouts. In consequence untold numbers of sailors died when their destinations suddenly loomed out of the sea and took them by surprise.
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 George III and Louis XIV. Seafaring men such as Captain Bligh of the Bounty and Captain James Cook took the more promising methods at sea to test their accuracy and practicability.
Renowned astronomers approached the longitude challenge by appealing to the clockwork universe. Palatial observatories were founded in Paris, London and Berlin for the express purpose of determining longitude by the heavens.
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 determination of the weight of the Earth, the distance to the stars, and the speed of light.
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 periodically roiled the fervour 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 for a "Practicable and Useful" means of determining longitude.
English clockmaker John Harrison, a mechanical genius who pioneered the science of portable precision timekeeping, devoted his life to this quest. He accomplished what Newton had feared was impossible: He invented a clock that would carry the true time from the homeport, like an eternal flame, to any remote corner of the world.
Harrison, a man of simple birth and high intelligence, crossed swords with the leading lights of his day. He made a special enemy of the Reverend Nevil Maskelyne, the fifth astronomer royal, who contested his claim to the coveted prize money, and whose tactics at certain junctures can only be described as foul play.
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. He did away with the pendulum, and he combined different metals inside his works in such a way that when one component expanded or contracted with changes in temperature, the other counteracted the change and kept the clock's rate constant.
Members of the scientific elite, who distrusted Harrison's magic box, however, parried his every success. The commissioners charged with awarding the longitude prize - Nevil Maskelyne among them - changed the contest rules wherever they saw fit, so as to favor the chances of astronomers over the likes of Harrison and his fellow "mechanics". But the utility and accuracy of Harrison's approach triumphed in the end. His followers shepherded Harrison's intricate, exquisite invention through the design modifications that enabled it to be massed produced and enjoy wide use.
An aged, exhausted Harrison, taken under the wing of King George III, ultimately claimed his rightful monetary reward in 1773 - after forty struggling years of political intrigue, international warfare, academic backbiting, scientific revolution, and economic upheaval.
All these threads, and more, entwine in the lines of longitude. To unravel them now - to retrace their story in an age when a network of orbiting satellites can nail down a ship's position within a few feet in just a moment or two - is to see the globe anew.
In our coming February episode, you will be told some of the extraordinary tales of the sea before time.
