A master cabinetmaker and self-taught clockmaker, the Englishman John Harrison left his mark on the 18th century – and, beyond that, on the entire history of horology – thanks to two major inventions: the pendulum and the marine chronometer. Once viewed with suspicion by his peers, he gradually joined the pantheon of great names in horology.
John Harrison, or the Art of Crafting Wooden Timepieces
The hallmark of great inventors is their ability to defy time. John Harrison is one of them. In April 2015, the National Maritime Museum in London hosted the presentation of an award from the Guinness Book of Records for the ‘most accurate mechanical pendulum clock,’ a timepiece known as ‘Clock B,’ designed by Harrison… 250 years earlier! This timepiece indeed proved to be accurate to within one second over a period of 100 days. A project that at the time was considered ‘so incoherent and absurd’ that it bordered on ‘the symptoms of madness’ (read more in this article in English).
This anecdote alone perfectly summarizes who John Harrison was: a genius of his time, ignored by his peers, whose innovative and meticulous work would only be recognized much later.
Throughout his life, the man embodied a commitment to precision. So much so that he died on the exact anniversary of his birth, March 24, 1776, in London, at the age of 83. Born in Yorkshire, young John Harrison developed an early interest in horology. And for good reason: at the age of 6, the boy, suffering from chickenpox, was confined to bed for long days, shut in his room. To distract him, his parents gave him a watch, the workings of which young John explored for hours. This marked the beginning of a passion that he would perfectly combine with his other talent: cabinetmaking.
As an adult, Harrison distinguished himself by manufacturing wooden clocks, which provided numerous opportunities to produce innovative mechanisms. Around 1720, he fulfilled an order from the town of Brocklesby Park for a new clock: his creation, made entirely of oak and lignum vitae wood, featured a homemade invention, the ‘grasshopper escapement,’ a friction-free movement that required no lubrication. Then, between 1725 and 1728, with the help of his brother James, also a cabinetmaker, he designed three pendulum clocks – another invention of his own. The bimetallic pendulum, resistant to temperature changes, would become a major creation in the history of horology.
But the other invention that would make Harrison famous, to which he would literally dedicate a major part of the rest of his life, was the manufacture of marine chronometers. An object that profoundly changed navigation.
Here is a selection of horological inventions attributed to Harrison:
The bimetallic gridiron pendulum, made of steel and brass – an alternative to George Graham’s mercury pendulum.
The ‘grasshopper escapement,’ a recoil escapement for pendulums – but so difficult to adjust that it was used primarily by Harrison himself.
The ball bearing.
History of the Invention of the Marine Chronometer
In the field of maritime exploration, the precise determination of longitude (the east-west position of the ship) has always been a problem, sometimes causing very significant directional deviations. To solve it, scientists explored two solutions from the 16th century onwards: the first involved using the position of a celestial body like the Moon; the second required the use of a precision clock, carried aboard the ship.
Among other European states concerned with finding a lasting solution, the British government launched a competition rewarding the first person to find a way to accurately calculate longitude: this was the Longitude Act, passed in 1714, offering a very high reward of 20,000 pounds to the winner.
Following Henry Sully, who proposed his own invention, the ‘sea watch,’ to the French Academy of Sciences in 1716, Harrison embarked in 1730 on the design of a marine chronometer. Financially supported by clockmaker George Graham and astronomer Edmond Halley (of comet fame), Harrison worked for five years to present the H1, his very first marine chronometer. In 1736, he embarked on a voyage to Lisbon and back, calculating the ship’s exact position using his invention. Impressed, the Board of Longitude jury, responsible for judging candidates, granted him a 500-pound stipend to continue his research – to obtain the full reward, the method had to be tested on a transatlantic voyage.
Two more compact and precise versions followed, the H2 and the H3. The H2 was finalized in 1741, after three years of work, but a war between England and Spain then broke out, preventing him from carrying out the sea trial. The forced delay gave him the opportunity to work on his H3, with which he corrected a design error in the H2’s balances.
Drawing inspiration from a new escapement he designed for a precision watch in 1752-1753, Harrison embarked on the creation of the H4 chronometer. This colossal undertaking took him six years. Completed in 1759, this chronometer, called a ‘sea watch,’ was presented in two silver cases, with a winder, for a total diameter of approximately 13 cm. It was high time to conduct this full-scale test: Harrison sent his son, William, to prove the reliability of the H4 during a voyage to Jamaica. Upon arrival, the chronometer’s error was only 5 seconds, equivalent to 1.25 minutes of longitude. The British Parliament deemed this insufficient proof. A second voyage took place, to Barbados, with the same William and the same chronometer. This time, the error was 39 seconds, or approximately 15 km. However, it should be noted that each time, the error recorded by the chronometer was infinitely less significant than that of the calculation, performed in parallel, based on the Moon’s position. Once again, he was refused in 1765, being offered only half of the prize.
It was not until 1773, and in favor of the H5, the latest version of the marine chronometer, that Parliament finally paid Harrison his due remuneration… Which still only amounted to half of the total prize originally planned! And this was only made possible by the intercession of King George III, directly petitioned by Harrison, and positively impressed by the H5’s results. Harrison was then 80 years old.
For English speakers, here is a very comprehensive account of the history of Harrison’s marine chronometer manufacturing.
John Harrison’s Place is Rightfully in a Museum
Although rewarded during his lifetime, in 1749, with the Copley Medal for his horological work, Harrison suffered throughout his existence from a certain lack of recognition, of which the Board of Longitude’s obstinacy and the reactions to his ‘Clock B’ project were but examples. It was not until long after his death that his genius was truly recognized.
After World War I, Harrison’s clocks were rediscovered by a retired naval officer, Rupert T. Gould: they were gathering dust somewhere within the Royal Greenwich Observatory. Gould dedicated much of his time to research in order to restore these precious timepieces. He also published a seminal work in 1923 that continues to be authoritative in its field: A Detailed History of the Chronometer and its Pioneers, in which he gives ample space to Harrison’s inventions.
Today, the clockmaker and cabinetmaker from Yorkshire rightfully belongs in museums. His wooden clocks and pendulums are exhibited, notably, at the Leeds Museum and Galleries, the Science Museum, Nostell Priory, as well as within the Worshipful Company of Clockmakers’ Collection. As for the marine chronometers, they have found their place in the Greenwich Observatory, London. An observatory founded in 1675 by Charles II to solve the problem of calculating longitude at sea.
