If you are in London with a day or a few to kill and are horologically inclined (and you probably are, because if you are not my condolences on having ended up here) you should be aware that there are a tremendous number of interesting exhibitions at London's numerous museums, which are at least as worth a visit as the city's numerous new watch boutiques and vintage watch dealers. The British Museum, the Victoria and Albert Museum, and the Science Museum all have a great deal to offer, with the Science Museum housing the collection of watches and clocks donated and curated by the Worshipful Company of Clockmakers.
Of these three (all of which I visited this week), the last is probably the one you should visit if you can only visit one. It is almost exhaustingly rich in scope and in the sheer number of watches, and it's even got a dedicated George Daniels section, but the British Museum is a close second, with many, many pieces worth seeing – one of which is the oldest existing clock known with a fusée.
This astronomical table clock was made in Prague by Jacob Zech and completed around 1525 (Prague has a very famous astronomical tower clock, and was a major clockmaking center during the early 15th and 16th centuries). There is an inscription in Old German around the dial that reads "when you count the years 1525 Jacob Zech made me in Prague – it is true." There's no chain; spring-powered table clocks from this period used catgut instead (often, surviving clocks with fusées from this era have had chains installed at some point). This was obvious a prestige object; it would have been well out of the budget of anybody but a king, wealthy cleric, or merchant prince; the clock was made for King Sigismund I of Poland. The dial shows "Bohemian hours" (that is, the day starts at sunset) as well as the position of the Sun in the Zodiac and the position of the Moon.
The is older than spring-driven clocks, and was used, before it was used in clockmaking, in war: for winding crossbows. The purpose of using a in a crossbow windlass would have been the same as in a clock: to provide a greater and greater mechanical advantage. In a clock, it's to provide a greater advantage to the mainspring as it runs down; in a crossbow, it's to provide a greater advantage as the tension in the bow increases, while at the same time letting you begin cocking the bow fairly quickly and efficiently.
This clock was made by Thomas Starck, in Augsburg, around 1620. The case has been lost at some point but the dial and movement are intact through some miracle. It's another astronomical clock; the dial shows the Dominical Letter for any given date (used to find the day of the week for a particular date; this was used by the Church as an aid in calculating saint's days, and moveable feasts) and the blue and white sectors show the length of the day and night. The clock also has an indication for the "head and tail of the dragon" – the astrological term for the moon's nodes, or the points where the orbit of the Moon crosses the plane of the ecliptic. When these points lie directly between the Earth and the Sun, an eclipse can occur.
This utterly absurd horological confection is arguably only incidentally a clock – it was designed, say the Museum's notes, to announce "the beginning of banquets at court" and was made around 1585, for the Holy Roman Emperor Rudolf II. It's in the shape of a , which was the French word for a type of ocean-going galleon prevalent in Europe in the 14th and 15th centuries (called a in Portuguese). The clock could run for about a day, and rang at the hours and quarters; striking was done by figures of sailors in the crow's nests. It was however primarily an automaton – when activated, it would move along a table, playing music via a drumskin on the underside of the ship and a mechanical bellows hidden inside. At the end of its run, the main cannon in the bowsprit would fire, igniting a match that would make the other cannons fire one after the other. It was made by one Hans Schlottheim, the son of a clockmaker, who was born in Saxony but practiced clockmaking in Augsburg. He seems to have specialized in this sort of thing; at least two other ship automatons by the same maker were known.
Schlottheim was a Master of the Augsburg clockmaker's guild and the fact that he had such powerful patrons would have been its own form of job security as well, giving him a freedom of activity that clock and watchmakers with less prominent friends might not have had, especially under the restrictive interpretations of guild rules in his day.
One of the most dramatic clocks at the Museum (albeit in a quiet way) is an astronomical regulator made in 1676 by Thomas Tompion, for the Royal Observatory, which has a thirteen foot pendulum beating every two seconds. The escapement was based on a design by Tompion's contemporary, Richard Towneley, with refinements to the design by Tompion, and was made at the behest of the first Astronomer Royal, John Flamsteed, with the express purpose of improving observations on which determination of longitude could be based. Obviously there was no thought that this particular clock would be suitable for use at sea; rather, it was intended to help the Royal Observatory make accurate enough tables of the motion of celestial bodies to make determination of longitude at sea by observation, a reasonable possibility. The pendulum moves, unusually, back to front, and the dial for the seconds hand is graduated for a seconds hand that takes 120 seconds to go around once.
This unusual clock was designed by William Congreve, an artillery officer perhaps most famous for the military rockets he designed. Congreve rockets were used extensively in the early 1800s; they were fired from British ships during the bombardment of Fort McHenry in the War of 1812 (they're the rockets referred to in "The Star-Spangled Banner.") Congreve's designs were based on rockets used against the British by the Mysore Army in India, which in the late 1700s had the distinction of being the first army to have a regular rocket artillery corps. As many were in his day, Congreve was a bit of a polymath and inventor and this rolling ball clock was one of his creations; this particular example was made in 1830. A ball rolls down the track in the tray in the lower part of the clock, and when it hits the end of the track it trips a lever that activates the mainspring-driven mechanism, which tilts the track the other way so the ball can roll to the opposite end, where it trips another lever.
The ball's run was timed so as to take exactly 30 seconds. Congreve hoped the design would be a major improvement in timekeeping accuracy, but this turned out to not be the case as the speed of the ball could be upset by everything from changes in temperature and humidity, to dust falling onto the tray. However, they were very popular anyway, as they're lots of fun to watch and the Congreve clock at the British Museum usually has a crowd around it.
As you might expect from a museum in a country one of whose most popular patriotic songs says something about Ruling The Waves, marine chronometers are very well represented. These two represent two very different approaches to precision timekeeping at sea. On the left is a very sophisticated marine chronometer completed in 1774, by Thomas Mudge. Less than twenty years before, John Harrison's H4 marine chronometer, fitted with an extremely high-test version of the ancient verge escapement (Harrison's had diamond pallets, with a most unusual geometry) had had its successful sea trials, and using variations on this escapement still seemed, to Mudge, a viable course to pursue. Mudge's sea clock shown here had a very complex, constant force verge escapement, with two spiral springs alternately delivering energy directly to the escapement and balance. This marine chronometer had two separate dials for the time at Greenwich, and local time (which would be established by observation) and the sector at the top would display the longitude. Mudge may not have really realized it (or may have just been in denial, or infatuated with his own powers of invention) but by the time he made this chronometer it was already obsolete. The detent escapement had been invented by Le Roy in 1748 (although his version did not work very well) and the very next year after Mudge finished this chronometer, John Arnold showed his pivoted detent escapement, which, in Thomas Earnshaw's variation of 1780, would become the standard for marine chronometer design.
On the right is a marine chronometer made by Breguet, in 1813. It has a lever escapement, bimetallic balance, and is housed in a gimbaled box. In every respect it is simpler than the Mudge chronometer, which preceded it by only four decades and yet it is light years beyond the Mudge design in terms of practicality as a timekeeper. In its technical specifics it represents what would basically become the standard for accurate portable timekeepers, right up until Charles Guillaume invented temperature resistant nickel-steel alloys in the 1920s (which made bimetallic balances obsolete). The difference between the two is expressed especially clearly by the Museum's notes on each chronometer; the entry for Mudge runs to nearly short book length, while the Breguet requires only a paragraph. As with Harrison's H4, the Mudge chronometer is a wonderful piece of incredibly ingenious, highly complex design – but it is also in many respects an ending, not a beginning.
Finally, I found something rather wonderful in the section of the Museum devoted to Japan. Above is a fully articulated model of a snake, done in gilded iron, and it was done by someone whose family name Seiko fans might remember. This snake was made in the late 1700s, by one Myochin Muneyoshi. The Museum also has an articulated iron carp, and an iron praying mantis from the same period; these iron animals were intended to mimic the motion of real animals as exactly as possible, and though of course I didn't actually handle this metal snake, it lies across the base of its vitrine with sinuous, reptilian verisimilitude. The Myochin clan have been iron and steelworkers for over eight hundred years, and of course, they provided the steel used in the gongs for the Credor Spring Drive Minute Repeater. I'd known this for many years but seeing something made by the Myochin family (and so beautifully made too) suddenly made the connection much more real.
Not only is it worth visiting the British Museum's watch and clock collections if you are a watch enthusiast and you happen to be in London, it is very much worth making a special trip to see it – especially since you can combine it with a visit to the Science Museum's collection, about which more in an upcoming post. We all have a general sense that our watches are part of a much larger and very rich history and there's nothing better than finding out about that history first-hand.