John Harrison & the Longitude Problem

John Harrison is certainly a legendary figure in the world of horology. Despite no formal training or even a formal education, Harrison solved the so-called Longitude Problem, and in doing so made some immeasurable contributions to watchmaking. Here is his story.

John Harrison It was the astronomer Ptolemy who first made reference to lines of latitude and longitude around AD 150, in his work Geographia. Unfortunately it took from then to the Renaissance for these imaginary lines to be revisited with any seriousness and used for practical navigation of the world's oceans. By this time mariners had fairly accurate charts that had lines of latitude marked on them that enabled them to locate their position with reasonable accuracy north or south, with reference to the positions of the sun and stars.

Longitude, however was another story. Finding the position east or west with any degree of accuracy proved to be one of the most difficult of problems. For many decades astronomers, mathematicians, physicists, horologists and mariners all struggled to solve one of the then great mysteries of human kind. With disasters at sea becoming more prevalent as shipping increased, it became evident that a solution to the so called "Longitude Problem" must be found.

Because sea power was so important for nations to prosper overseas, Governments offered up huge rewards for the solution to the problem. As early as 1598 Phillip III of Spain offered 6000 ducats, a life pension of 2000 ducats and a gratuity of 1000 ducats, to anyone who could successfully solve the problem. Holland offered the sum of 1000 to 30,000 guilders and France 10,000 livres as a Prix Rouille in 1715. But it was the British Government that offered the biggest prize of all.

In 1714 Parliament passed an Act "for providing a Publick Reward for such Person or Persons as shall Discover the Longitude at Sea". The method of payment was to be "£10,000 for any method of deterring longitude within one degree, £15,000 to within 40 minutes of arc and £20,000 to within 30 minutes of arc".

In order to oversee methods of determining the solutions, a Board of Longitude was set up and over the period 1714 to 1828 paid out some £100,000. Such a huge prize on offer attracted a great number of crooks and cranks, and for this reason the Board became somewhat skeptical about any and all solutions that were presented before it.

One of the more fanciful solutions thought of at the time was by using a timekeeping instrument that would be able to stay accurate to within six seconds per day in order to maintain an accuracy of 60 miles over a six week voyage. This degree of accuracy for a timepiece was considered impossible to ever achieve at the time and this was confirmed by many eminent men such as Newton, Halley, Huygens, von Leibnitz and Hooke.

Christian Huygens (1629-95) was first to create a clock designed solely for the purpose of solving the longitude problem. He was the inventor of the first Pendulum clock that had revolutionized the accuracy of clocks on land. He therefore thought that the pendulum was the perfect solution to the problem at sea. To combat the rolling ship, he proposed supporting the clock inside a gimbaled mechanism and considered that this would be adequate to counter the rolling oceans. Unfortunately he was wrong and all his clocks would behave in a most erratic manner, stopping, jerking and proving most unreliable. He then moved on to watches, and although did have some success making them more accurate than they previously had been, could not get them to maintain any degree of accuracy for more than a few hours.

Several others tried unsuccessfully with various designs that all suffered in a similar way to the pendulum clock, that is that while on land they demonstrated reasonable accuracy, while at sea their reliability failed miserably. Enter a remarkable man by the name of John Harrison.

John Harrison (1693-1776) is not only a remarkable man, but his genius becomes even more apparent when we consider that he had no formal training in clock making, nor even any formal education to speak of. Coming from the (then) small village of Barrow in Lincolnshire, England, his interest in clocks and timepieces began at a very early age. The history of Harrison is sketchy to say the least, but we do know that with his brother James, the two had created many important long case clocks before 1726 that were said to be accurate to within one second per month. Their design and construction was based around reducing friction to an absolute minimum, eliminating the need for oil as a lubricant, and incorporating certain ingenious solutions to the problem of expansion of materials due to temperature change.

The trials and tribulations of John Harrison with the Board of Longitude are well documented and will not be repeated here, except to say that after his first visit to the Board in 1730, it was not until 1760 that his masterpiece, H4 was created that essentially solved the problem. Indeed, if it were not for the false reporting by the Reverend Nevil Maskelyne that the watches "drift rate" (amount of gain or loss per day) was a fault of the watch, the prize should have been won at that stage. Harrison continued however, and created another watch, H5, while the Board refused to allow John Harrison access to H4.

John Harrison's Timepieces

H1 - John Harrison's No.1 Sea clock was his first attempt at solving the problem of Longitude. It was a huge clock, measuring about three feet wide and tall and weighing 72lb (33kg). It was an unusual looking clock too but at sea it performed admirably. Instead of a pendulum the clock had two five pound weights that counteracted the movement of a rolling ship and proved accurate to around three seconds per day. However, after five years in the making, Harrison was not satisfied with H1 and announced to the Board that he would start work on another clock, H2.

The picture on the right is actually a remarkable replica of H1, made by an equally remarkable company called Sinclair Harding. Visit their website and see all their clocks.

H2 - Incorporating an improvement that increased the accuracy, the remontoire, a device that maintained a constant force on the escapement, H2 was designed to occupy less deck space on board ship. It was however still quite a large and heavy clock. While John Harrison was working on H2, he was also making another, H3

H3 - H3 was slightly smaller and lighter than it's predecessor but could not be adjusted without dismantling a fair amount of the clock first, not a practical solution. However, H3 incorporated two major improvements, use of a bi-metallic strip to counter changes in temperature and roller bearings to counter the effects of friction on the movement. H3 was a turning point in John Harrison's thinking on the Longitude problem. After its completion he became convinced that the large clock was not the way to go for a practical solution. He therefore changed direction and incorporated all his previous inventions into a watch - H4.

H4 - H4 was a major side-step away from designing large clocks. This one was instead a large watch, similar to a pocket watch but much larger at 5.25 inches diameter. This priceless heirloom is today kept at the National Maritime Museum at Greenwich. Incorporating all the previous design features of its earlier models, including diamond pallets to the special verge, maintaining power, a remontoire, and a center seconds hand, H4 used oil as a lubricant rather than the completely oil-free earlier models. It proved itself to be more than capable of keeping accurate time at sea when trialed by John Harrison's Son, William on a trip to Jamaica. When the ship arrived in Jamaica it was shown that the watch had lost a minuscule 5 seconds (after rate correction*).

*Correction should be explained - The rate of any watch is its consistency in going. A timepiece may be known to gain X seconds per day or lose X seconds per day. At the end of any trial, the gain or loss needs to be added or deducted to/from the final result. If a watch varies from fast to slow, then of course it would be impossible to know what correction to make to the final result, if any. In the case of H4, the necessary correction was known, due to land observations made prior to the voyage.

H4 eventually ended up in the hands of the Admiralty after the disgraceful blackmail of Harrison, the Board insisting that unless he handed over the watch in order that its secrets be known and copied, he would receive no prize. The watch was handed over and a watchmaker by the name of Larcum Kendall began work on a copy of the watch, known as K1. Harrison continued with his lobbying of Parliament, his efforts eventually resulting in a belated payment of £8750, making a total payment of £18,750.

Harrison's final publication in pursuit of his rightful prize was made in 1775, the year before his death. In it he wrote:

...if it so please Almighty God, to continue my life and health a little longer, they the Professors (or Priests) shall not hinder me of my pleasure, as from my last drawing, viz, of bringing my watch to a second in a fortnight...And so, as I do not now mind the money (as not having occasion to do so, and withal as being weary of that) the Devil may take the Priests...

Larcum Kendall's K1 was taken by Captain Cook on his journey crossing the Atlantic Circle for the first time in history. Cook said of K1, "Mr. Kendall's watch has answered beyond all expectations", and referred to it as "our never failing guide, the Watch".

John Harrison died on the 24th March 1776, aged 83.

Take a look at the incredible John Harrison H1 Replica by Sinclair Harding