Jonathan Betts

Jonathan Betts


Senior Curator of Horology, Royal Observatory Greenwich

Jonathan BettsI oversee the work of the Horology Section and research into the history of clocks, watches and chronometers, with the emphasis on precision timekeeping and its use in navigation and determining longitude at sea. My work includes curating exhibitions, writing books and articles, and cataloguing of the horological collections. It sometimes involves giving interviews to the press, TV and radio, giving talks and lectures, conducting specialist tours and so on. I also undertake the practical care and conservation of the collection and oversee the day-to-day operation of the working clocks.

My favourite part of my job

It's rewarding to be able to dismantle and study the objects in our horological collection, and research the history of those objects, the people who made them and the people who used them. Seeing the research work published is then a very rewarding means of sharing the discoveries. The care of the collection includes looking after the great marine timekeepers by John Harrison which is a huge and exciting privilege.

The question I'm asked most often

Why did Harrison make three great big timekeepers (H1 to H3) and then win the longitude prize with a very small one (H4)?

It was not, as many people think, a case of perfecting the principles and then miniaturising. Harrison started big because big clocks, controlled by a pendulum, were very accurate (many times better than needed to win the big prize) and watches at that time were hopelessly bad at keeping time. One of Harrison’s greatest achievements was to realise that in fact something on the scale of a watch was nevertheless the solution to creating a marine timekeeper. All it needed was to have the proportions of the timekeeping element (the balance and balance spring) redesigned. This led to the precision watch, an article which people wore in their pockets and on their wrists until the advent of quartz technology in the 1970s.

My recommended books

The classic work on the marine chronometer is called (unsurprisingly) The Marine Chronometer and is by Rupert T.Gould. It was published in 1923 but is still the best on the subject. Another comprehensive but accessible work on the history of longitude and the chronometer is The Quest for Longitude and for an easy, compact version of the Harrison story, Dava Sobel’s celebrated book Longitude, is a great read (though take the villainous portrayal of the Astronomer Royal with a pinch of salt!). If you’re into precision pendulum clocks, then Philip Woodward’s book My Own Right Time is a fascinating work, and Derek Roberts three-volume set, Precision Pendulum Clocks will provide loads of interest, along with lots of fine illustrations.