The history of watchmaking is not only discoveries and inventions. It is the history of the men who built it, step by step, according to the design of new engineering mechanisms and the development of new marketing methods.
In his book Longitude: The true story of a lone genius who solved the greatest scienti7c problem of his time, Dana Sobel tells the story of John Harrison, the inventor of the marine chronometer, who solved one of the great scientiDc problems of his time.
I would like to share here my readings and my thoughts about what we can learn from the longitude problem.
The Longitude Problem
The longitude problem has complicated life of navigators and scientists for centuries. This is an exploration of the many solutions, good and bad ideas, that have been tried.
Determine longitude is a harder problem than finding latitude which can be resolved from the position of the Sun.
Lines of latitude and longitude began crisscrossing our worldview in ancient times. By A.D. 150, the cartographer and astronomer Ptolemy had plotted them on the twenty- seven maps of his first world atlas.
It establishes a list of places with longitudes and latitudes. It is he who invents these words constructed on length and breadth because the inhabited world extends over 180 ° of longitude and 80 ° of latitude approximately. Similarly, he invents the word “climate” and the notion of parallel, calculating the length of days and nights according to latitude. The difference of about 20 degrees in longitude stems from Ptolemy’s choice to leave the Canaries to have only positive longitudes.
None of the possible maps he had drawn have reached us. When this scholar was rediscovered at the end of the Middle Ages through Arabic writings, his maps were redrawn.
We can see that the scientists found the processes which, after more than two and a half centuries of work, were to provide the solution sought. On the one hand, use of the instantaneous signals that the sky presents, visible both over an entire hemisphere and whose instant has been calculated in advance in time of the first meridian. On the other hand, the construction of a device making it possible to keep the time of the first meridian with great precision.
To observe all phenomena usefully, it would have been necessary to have enough powerful glasses with which the observatories of the seventeenth century were just beginning to be equipped, assuming that such glasses could be used on a ship.
Attempts were then made to keep the time of the prime meridian on board using clocks. They tried successively 24-hour hourglasses, water and mercury clepsydra, pendulum clocks, and so on. All these attempts were in vain.
Start With Why
Knowing the longitude involved the use of devices that could solve concrete and practical problems. But why was it so important? Having a safe method of calculating longitude was crucial for Europeans traveling in the southern seas, involved both establishing effective protocol and teaching others.
Until the end of the first third of the 19th century, the method of lunar distances prevailed over the chronometric method because imperfect watches required constant control by astronomical observations. As chronometers became more and more reliable, the lunar methods had to be used less and less, to be completely abandoned.
In 1707 four ships of the Royal Navy under the command of Vice-Admiral Cloudesley Shovell ran aground off the Scilly Isles while returning from the Mediterranean.
More than 2,000 sailors died and Shovell’s reputation was ruined, all because no one at the time could properly calculate longitude. The Admiralty determined it would never happen again, not a little to do with petitions from sailors.
The Board of Longitude was born. His mission was to find new ways to fix an east-west position at sea. The British Parliament, in its famed Longitude Act of 1714, set the highest bounty of all for anyone who could locate a position with an accuracy of 30 nautical miles.
English clockmaker John Harrison (1693–1776), a mechanical genius who pioneered the science of portable precision timekeeping, devoted his life to this quest.
He learns that the Board is offering a prize of £ 20,000 (5 million dollars in today’s currency) for the resolution of the longitude problem. This initiated a flood of proposals for finding longitude and started a lengthy process of experiment and analysis.
John Harrison set to work and built an H0 wooden clock but with a pendulum. So it’s not a stopwatch but it invents solutions for the regularity of movement.
In 1730, John Harrison drew up blueprints for a marine chronometer to find financing for its manufacture. He goes to London and contacts Halley who admires his work but he does not know how to evaluate it and directs him to George Graham, head of the corporation of master watchmakers. Graham advances him funds to continue his work.
He spent six years building his first stopwatch, which would later be called H1, and completed it in 1735. This rather heterogeneous chronometer (33 kg, 90 cm side), there was still wood, was tested at sea in 1736. This marine watch looks like what in the startup world is called an MVP (Minimum viable product).
The MVP is the first step in development taking into account customer and user's feedback and remarks. In this case, they are these are the Board of Longitude and navigators. Conclusive test which enabled him to obtain a subsidy from the Board.
Leaving H1 aside, John Harrison began building an improved version, H2, which was completed in 1740. It was clearly a refined version of his first.
The resonator of the first 2 marine clocks of John Harrison H1 and H2, their beating heart, is a pair of twin balances of about 3 kg each which punctuate the flow of time: 1 second per half period of pendulums in a Galilean reference frame.
No sooner had John Harrison completed H2 on this principle common to his first clock, than he realized that this resonator was partially affected by the movement of the boat.
He noted this in a manuscript kept, undated but after 1740. John Harrison records a relevant qualitative analysis of the sensitivity of the balance to centrifugal forces. This is probably the reason why he will give up a sea trial of H2 and will undertake the realization of a 3rd marine clock.
The whole process of this industrial invention was incremental, that is, it changes step by step. John Harrison saves time and resources thanks to relatively “short” development cycles, which is reminiscent of the methods we use today in digital product development as Agile and DevOps.
In 1757, construction of H3 with little progress, but experimenting with new solutions to solve some problems. The sensitivity of the clocks to the movements of the ship is due to different moments of inertia of their pendulums according to their main axes. A defect that John Harrison will correct with H3.
Again, we can observe that a process was iterative, with cycles that are repeated constantly but obviously these iterations or “sprint” were much longer at that time. One can notice the adaptability in the duration of the various releases. He already allows quick and immediate reactions. Every new version was clearly a refined version of the previous iteration.
H4 will finally follow, his famous marine chronometer, 13 cm in diameter starting in 1759, which will earn him fame after a successful test on a trip to the West Indies. Tested between 1761 and 1762 between London and Jamaica with excellent results. But astronomers are the sore losers. A second test is required in 1764 between Portsmouth and Barbados. 39s gap is less than 10’ angle (the rules required less than 30’).
The Jury is asking for all secrets and the French will seek to take advantage of the Jury’s bad faith by seeking to recover Harrison’s work for financial compensation. But they too will be too mean and the deal will not succeed.
It takes the personal intervention of King George III to finally get justice, but the jury withholds the £ 1250 in advance!
Agile and DevOps engineering principles have been around for a long time in the industrial process. The new technological tools of navigation in the 18th century, marine chronometers, quadrants, theodolites, and sophisticated compasses, had great symbolic importance. The ships functioned as real scientific labs.
The degree of perfection attained by chronometers no longer made it possible to consider as an effective means of control an astronomical method whose results were less precise than those which had to be verified. The observation and calculation of a lunar distance are long and delicate operations, and the confidence which one can place in the results obtained with mediocre observations cannot be very great.
The method was not at all times usable by the navigator in search of a point, since the moon needed to be up and more than two or three days from the new moon. Under these conditions, on high-speed vessels, the method would have been deficient. In the chronometric method which uses the measurement of the height of a star, all the stars are in principle equivalent as soon as the observer has their ephemeris.
To observe, it suffices that the sky and the horizon are exposed. The observations are simple, the calculations short, the result relatively precise if the chronometer is correctly set. One, therefore, understands the constant search for the improvement of chronometers and, these having achieved excellent qualities of accuracy and precision, the exclusive final use of chronometric methods.
Engineering is about understanding a problem and using technology to solve it as quickly as possible. Automate your navigation so as not to get lost at sea.
This period left a lasting mark on our acceptance of the term “chronometer”: we thus went from “any instrument used to measure time” to “high precision device certified by official authorities”. It was not until 1918, at least in principle, the realization would come in the 1930s, to experience a new scientific breakthrough: the quartz system.
Defer To Expertise
In doing so, John Harrison was solving problems on the way to achieving his objective of producing accurate timepieces.
When Lieutenant Commander Rupert T. Gould of the Royal Navy took an interest in the timekeepers in 1920, said about him: “It embodies several devices which are unique — devices which no clockmaker has ever thought of using, and which Harrison invented as the result of tackling his mechanical problems as an engineer might, and not as a clockmaker would”.
An example of his inventive genius was the problem-solving model that he used. This model was following eight steps:
Purpose → Locate → Collect → Analyse → Organise → Enact → Result → Review
A clear purpose in mind to produce an accurate solution. Locate the data.
Collect and gather information.
Analyze data and use his knowledge to combine ideas. Organize data and ideas to find the best solution.
Enact: After identifying problems, enacting solutions. Result: result delivered and refining.
Review what we learn through the previous steps.
He became interested very early in the problem of lubricating clockwork mechanisms, always putting the theories to the test. Harrison’s science is unique. He has a clear vision to make a clock with an error of one to two seconds per year using his theories.
After extensive research, Harrison experimented with his H4 chronometer during two voyages at sea from 1761 to 1764. Its precision proved to be superior to that required by the numerous competition regulations established since the end of the 16th century and which should reward this one which would solve the longitudes problem. During his research, he invented processes still used today. He defers to expertise, not to authority.
With no formal education or apprenticeship to any watchmaker, John Harrison traveled to London to gain support for his proposal to make a sea clock. Harrison himself packed up full-scale models of his inventions and drawings for a proposed marine clock and headed for London seeking financial assistance.
Harrison had focused on what most people considered a clock for longitude, a big stable device for a ship. John Harrison had come within half a degree in plotting their longitude. It took a second trial by his son William and some further wrangling with the Board. Harrison felt was being held hostage by the Board and decided to enlist the aid of King George III and obtain an audience.
He gave her his H5 for ten weeks, from May to July 1772, during which measurements were taken daily that showed the H5 to make an error of about a third of a second per day. The king is impressed. He calls on Parliament to grant the prize.
An aged, but victorious 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, a scientific revolution, and economic upheaval. Harrison was finally awarded the prize money. He receives two payments (1762 and 1765) after testing his fourth chronometer called H4 and the balance of the premium (1773) after producing a fifth and final marine chronometer.
Over a fifty-year period, John Harrison made at least three longcase clocks, a tower clock, and five marine clocks. What we don’t know is how many clocks he actually assembled and took apart to modify and reassemble.
John Harrison was a pioneer who seriously pursued a timekeeper solution to the longitude problem. Then suddenly, in the wake of Harrison’s success with H-4, legions of watchmakers took up the special calling of marine timekeeping. It became a booming industry in a maritime nation. Indeed, some modern watchmakers claim that Harrison’s work facilitated England’s mastery over the oceans, and thereby led to the creation of the British Empire.
Harrison certainly does “creative work in the context of prolonged, meaningful, and intrinsically motivating pursuits”.
As cabinetmaker and great watchmaker, totally self-taught, John “Longitude” Harrison revolutionized the field of marine clocks and chronometers. He showed the way to Berthoud and other inventors after him.
“He accomplished what Newton had feared was impossible: He invented a clock that would carry the true time from the home port, like an eternal flame, to any remote corner of the world.” — Dava Sobel, The Illustrated Longitude.