The AHS Blog
This post was written by James Nye
There is a fascinating article in the latest edition of Antiquarian Horology, just starting to arrive through people’s letterboxes, setting out a remarkable research question which cries out for some crowdsourcing of data—hence this blog post. For those who don’t receive a physical journal, the editor has conveniently made it the sample article for this quarter. You can download it here.
Put simply, it is suggested a range of prominent makers (or perhaps retailers) bought in largely finished movements from a single source, and arranged for their casing/signature/final finishing.
This is clearly a very well-understood practice in the watch world from a relatively early date, and was certainly common practice in the clock world later on. For example, Thwaites produced movements for a wide range of other clockmakers and clockmaking firms, and on a large scale.
The question remains, how early did this standard practice emerge, and is there sufficient physical evidence to allow us to draw firm conclusions?
The key element is that Jon’s piece is a call to arms! More data is needed. And it is not difficult to look for it. This is a massively worthwhile project to support, and whatever the outcome, if you can supply data you can play a part in improving our understanding of clockmaking practice in London in the period 1660–1720. Please do get involved!
This post was written by Jonathan Betts
Almost exactly ten years ago I had John Harrison’s magnificent first marine timekeeper H1 in my workshop at the Royal Observatory. It was being dismantled for study, cataloguing and conservation for the new chronometer catalogue.
I had a film crew with me making a documentary, and they were becoming exasperated at constant interruptions to the filming. Finally another telephone call – a man was outside, asking if he could see me. Embarrassed, I assured the film team I would politely ask him to come back another time, but explained they had to come with me as I couldn’t leave them alone with H1.
Outside, the man apologised for arriving without warning and that he could come back if necessary. He introduced himself, offering his hand and just saying softly “Neil Armstrong”.
One of the film crew laughed and remarked 'Ha! I bet with a name like that you get lots of requests for autographs!' to which the unassuming gent simply replied: 'I’m afraid I don’t do autographs'.
It was at that point that we collectively realised that we were indeed in the presence of history. Suffice to say, all anxieties about filming schedules melted away and we all returned to the workshop (but with film cameras firmly switched off!)
Armstrong had long been a Harrison fan and he and his golfing friend Jim, hearing on the grapevine about the H1 research, had taken a detour from a sporting trip to Scotland, to make a pilgrimage to Greenwich.
For a wonderful hour or so we discussed Harrison and his first pioneering longitude timekeeper and it was clear Armstrong’s reputation was correct – reserved, yet of great intelligence and hugely well-informed; in short, a thoroughly nice man and not at all the showman one imagines when thinking of lunar astronauts.
I always asked visitors to sign my Visitors Book, but understood when Armstrong explained 'if you don’t mind, I’ll do it in capitals'.
Hearing that Harrison’s second prototype timekeeper, H2, would be next for research in the coming year, Armstrong returned and I spent a little more time with him, getting to know him a little better and was privileged to learn more of the Apollo 11 mission, from the horse’s mouth, as it were.
As he and Jim left on that occasion I asked Jim to sign my book again, and as they got back into their car, Jim whispered to me 'I think you’ll find Neil signed properly this time too'.
And indeed he had, something I shall always treasure.
This post was written by Oliver Cooke
Antiquarian clocks are still in widespread use. However, like any machine, mechanical clocks wear out as they run and, to keep them running, repairs will inevitably be necessary.
The image above shows a three century old longcase clock pinion that is well worn. Such a change in form will hinder the correct running of the clock until, eventually, it may no longer run at all.
Current repair techniques involve replacing the lost material or the whole gear. Either method is likely to result in loss of evidence of the clockmaker’s original work. This information is important as it can help us to assess the authenticity and origins of clocks.
It would therefore be useful to find a way to reduce the wearing of the teeth in the first place.
Liquid lubricants, e.g. oils, are generally not used on the teeth of clock gears as they are typically exposed to the air, from which dust can mix with the oil to form an abrasive, or chemicals can form which can corrode gears.
Bonded solid lubricants (B.S.L.s) are dry and do not absorb contaminants from the air. B.S.L.s contain particles of dry lubricant, such as graphite, suspended in a binding agent, such as epoxy resin.
They are applied as a liquid which cures to form a hard, dry coating. This coating can both lubricate and act as a sacrificial wearing layer. B.S.L.s might therefore be a useful treatment for preserving the gears of clocks.
Over the last year at the British Museum, where we run antiquarian clocks in the gallery, I have been conducting trials of B.S.L.s on model gear teeth as part of an MA Programme in Conservation Studies at West Dean College.
The B.S.L. that was tested was found to reduce wear compared to uncoated gear teeth. However, scientific analysis showed that it contained chemicals that are unsuitable for use on historic parts.
There are however many other types of B.S.L. and, given the promising results, I plan to test more. It is hoped that this will eventually lead to a treatment to help to keep the antiquarian clocks running with their original gears.
Look out for more information in future editions of our journal, Antiquarian Horology.
This post was written by Rory McEvoy
In July 2014 the NMM hosted on one-day conference, entitled Decoding Harrison, which presented the story of around forty years of collaborative research into John Harrison’s complex and surprising pendulum clock theory.
During the conference the exciting result of a previously unannounced and unofficial test of Martin Burgess’s ‘Clock B’ at the Royal Observatory was revealed.
‘Clock B’ is one of two clocks made from modern materials, chiefly duraluminium and invar, that follow the perceived format laid out in Harrison’s convoluted text: Concerning such mechanism… the lengthy title gives the reader an accurate sense of the complexity of the book itself.
For example, footnotes occasionally run across more than one page and if that was not enough, some even have their own footnotes. In short, it is not an easy read.
The unofficial test was conducted with the clock sealed into a Perspex case, which was made tamper-proof by applying two wax impressions, kindly provided by the Worshipful Company of Clockmakers and the National Physical Laboratory on 1 April, 2014, over wires threaded through the nuts and bolts that hold it shut.
On 6 January, 2015 – some 280 days after the case was sealed – Museum staff and the Master of the Worshipful Company of Clockmakers, Jonathan Betts, gathered to witness the going of the clock and initiate an official 100-day trial of its timekeeping.
Using the a radio-controlled clock that receives the MSF time signal, the accuracy of the speaking clock was confirmed and then used to determine to going of ‘Clock B’. We determined that the clock was showing UTC -1/4 second.
The clock will be observed throughout the trial using the above method as well as being continually monitored by a Microset and GPS as well as the environmental conditions inside the case (temperature, humidity and barometric pressure).
The trial is intended to prove that this clock is the most accurate mechanical clock with a pendulum swinging in free-air in existence. Throughout the trial I will be blogging and posting updated videos to youtube, which you can subscribe to.
To wrap up this exciting experiment we will be presenting the data collected, the current understanding of how the clock works and, indeed, why it works so well in a one-day conference at the National Maritime Museum on 18 April, 2015, which incidentally will mark the 3 year anniversary of Clock B’s stay here in Greenwich.
Details of the programme will be announced shortly.
This post was written by James Nye
Featured in James Bond’s Skyfall in 2012, the former Port of London Authority building near London’s Tower Hill is undergoing significant change, to become luxury apartments and a hotel, badged 10 Trinity Square.
The building was opened in 1922 by Lloyd George, and its boardroom hosted a reception on 30 January 1946 in honour of the first session of the General Assembly of the United Nations, which had commenced earlier in the month ( The Times , 31 January 1946, p. 7).
The boardroom was recently the focus for dramatic renovation works, with original surfaces being repaired and refinished.
One relic from an earlier incarnation of the building to which the new owners turned their attention was the Gent Fig. C423 insertion feature clock, mounted in a panel above the balcony doorway.
This model was designed for the Festival of Britain in 1951. It is therefore clearly a later replacement of the movement first installed in 1922, but Colin Reynold’s excellent Conspectus of Clocks and Time Related Products Produced by Gent & Co Leicester (Leicester, 2011) illustrates the original pattern.
The current orphaned dial has lost the rest of its network of C7 master clock, and perhaps a hundred dials that might once have populated the building’s many rooms.
Johan ten Hoeve of The Clockworks was asked to attend to see what could be done to make it work.
Apart from the required servicing of the movement, the obvious solution was to provide a small self-contained master clock mechanism, quartz-controlled and battery-driven, to be hidden inside the panelling.
This parsimonious and relatively inexpensive solution has ensured the retention of a historic clock, in its original setting, and without the replacement of any parts. The old Gent lives to fight another day.
This post was written by Jon Colombo
At West Dean College, first year clock students make a hoop and spur wall clock from scratch. As far as practicable we use techniques available to an eighteenth-century clockmaker. This gives the deepest understanding of the mechanics, aesthetics and the way historic clocks are put together. Verisimilitude is important, but not critical. When making driving weights, students usually use brass tube, topped, tailed and filled with lead. As a former archaeologist, I wanted more authenticity.
Examining a selection of old weights showed:
- The joints do not seem to be soldered. Under a microscope, often the seam is marked by a thin copper-coloured line, likely to be loss of zinc from the brass.
- The joints are not brazed. It is common for the skin to split along the joint. Were they brazed, failure here would be very rare.
- Often the lead has shrunk away from both sides and hanger, leaving a hollow tube running down into the weight.
- The bottoms are almost always domed.
The first two suggest a butt joint. The third that the lead is stuck to the skin. It could be just the filling holding the whole thing together. Cooling shrinkage cooling would pull the skin into compression, and explain the need for domed base. The logic was convincing; time to try it.
I cut a skin and domed base of thin brass sheet, tinned and wired them tightly together. I then embedded the shell in sand and poured in lead.
Manufacture is simple, quick, economic – sheet formed on bar, butt joint filed, wired up and ready to go; hanger made from old wood screw.
The results were pleasingly close to the originals. The lead bonds firmly to the walls, heating them enough for the outside to take on a copper colour. In cooling the lead pulls the joint tight and forms the right shrinkage patterns. When I cleaned the weight, the copper colour was often left in the now very tight butt joint.
If you fancy giving it a go, or are simply curious, http://westdeanconservation.com/2014/06/05/a-68-minute-weight-with-verisimilitude/ gives a bit more detail.
This post was written by Peter de Clercq
You only have to walk around in your own town to observe that of all the public clocks you pass by, only a few tell the correct time. Many show just any time, others have stopped working altogether.
Last year, a tongue-in-cheek editorial in the Guardian suggested that it was ‘time for a public clock tsar, with power to demand that owners restore their timepieces to reliable service’.
Here I learned of the existence of the blogspot Stoppedclocks, which invites us to ‘help find and fix all the stopped public clocks in Britain’. So if you have a particular gripe about a faulty clock in your area, you now know where to turn to.
There is, of course, nothing new under the sun. More than three centuries ago a correspondent to a London newspaper ventilated his gripe about the unreliability of public time-pieces.
It is quoted here, with the numbers referring to the map, as published in an article by Anthony Turner entitled ‘From sun and water to weights: public time devices from late Antiquity to the mid-seventeenth century’, published in Antiquarian Horology in March 2014.
'I was in Covent Garden 1 when the clock struck two, when I came to Somerset-house 2 by that it wanted a quarter of two, when I came to St. Clements 3 it was half an hour past two, when I came to St. Dunstans 4 it wanted a quarter of two, by Mr. Knib’s Dyal in Fleet-street 5 it was just two, when I came to Ludgate 6 it was half an hour past one, when I came to Bow Church 7, it wanted a quarter of two, by the Dyal near Stocks Market 8 it was a quarter past two, and when I came to the Royal Exchange 9 it wanted a quarter of two: This I aver for a Truth, and desire to know how long I was walking from Covent Garden to the Royal Exchange ?'
(Quoted from The Athenian Mercury, vi no 4, query 7, 13 February 1692/93).
This post was written by Oliver Cooke
A common feature of watches and clocks of the 16th century are touch-pins. These are raised studs located at each hour position on the dial, with that at the 12 o’clock position typically being longer and sharper to provide a point of reference.
These enable the time to be read by feeling the position of the single, robust, hour hand.
This was useful as it was not possible to simply switch on a lamp to read the time at night. An added benefit might have been that the time could be read discretely under one’s robes.
This is a later variation of touch indication, known as a “montre à tact” (“touch watch”).
The exposed hand does not turn with the movement but it is moved manually, clockwise, until it stops at the right time. This is read against touch-pins that are located on the edge of the case.
These watches are also sometimes known as “blind-man’s” watches but, although they could have served as such, they were conceived as night watches.
This watch, however, was clearly designed to be used by visually impaired persons as it has Braille numerals on the dial.
Mass production of watches and clocks became established in the 19 th century and it enabled them to be affordable to the masses and, subsequently, the massive new market enabled a much greater variety to be economically viable, including this Braille watch.
This wrist-watch bears the latest incarnation of touch indication.
The time is indicated by steel ball bearings which run in tracks, positioned by magnets driven by the movement within the case – the hours around the perimeter and the minutes on the front of the watch.
The balls are easily displaced, which prevents damage to the movement, but are easily relocated with a twist of the wrist.
The watch was conceived for use by visually impaired persons, but its elegant design appeals to a far larger market. The development of this watch somewhat parallels that of the Braille watch, as it also depended on a fundamental development in technology and economics.
This watch was brought to market through internet “crowd-funding”, whereby many individuals invest a relatively small amount each to raise the total capital necessary to fund the development of a product (in this case enabled by Kickstarter). Crowd-funding can enable some exciting projects to succeed which might have been rejected by more traditional investors.
This post was written by Rory McEvoy
In 1775 John Harrison made a critical remark about Graham’s dead beat escapement, saying, of George Graham, that '…either he must be out of his Senses, or I must be so!'
Later in the same publication he stated of his own clock that '…there must be then more reason…that it shall perform to a second in 100 days…than that Mr Graham’s should perform to a second in 1.'
Keeping time consistently to within one second in 100 days was a degree of accuracy not achieved until around a century and a half later by mechanical clocks such as Shortt’s free pendulum system.
Harrison published his remarks in a vitriolic and virtually impenetrable book, the manuscript and transcriptions of which are freely accessible online.
On reading the book, which contains scattered descriptions of his method, the celebrated watchmaker Thomas Mudge, stated of Harrison that the book’s contents had '…lessened him very much in my esteem…' and that '…there are several things which he says about Mr Graham’s pallets and pendulum that are absolutely false…'.
The London Review of English and Foreign Literature described the work as 'one of the most unaccountable productions we ever met with' and went on to say that 'every page of this performance bears marks of incoherence and absurdity, little short of the symptoms of insanity'.
Harrison’s words were not taken seriously by any of his contemporaries and his radical statement about the capabilities of his pendulum clock, with its large pendulum arc, relatively light bob, and recoil grasshopper escapement, remained largely unexplored until the 20th century.
Then, in 1977, a number of horological scholars, who became known as The Harrison Research Group, began to look at his theories afresh.
Martin Burgess’ Clock B is a product of this collaborative research and represents one of the most significant historio-technical investigations in recent years. Recently, numerous experiments have been tried on the clock at the Royal Observatory, Greenwich with exciting results.
To learn more about this intriguing project please join us for a special one-day conference on July 12 2014 at the NMM.
This post was written by James Nye
A gauntlet has been laid down. Across Europe, thoughtful people are busy working up ingenious ideas for a competition devised over an extraordinary April weekend in southern Germany.
The fifteenth of these gatherings—a combination of market, lectures and much eating, drinking and good conversation—saw a new visitor who brought many interesting items, not least several hundred new-old-stock Reform movements, tissue-wrapped and boxed.
As David Read comments, these Schild movements are ‘without doubt the best known and most commercially successful of all the many varieties of electrically-rewound clock movements’ from the 1920s onwards. The calibre 5000 is a lovely object, jewelled, with damascened plates, and micrometer regulation.
Nye’s theorem proposes that hi=as*bc/ebw where hi stands for horological inventiveness, as represents afternoon hours of sunshine, bc denotes beers consumed and ebw stands for evening bottles of wine.
With a lively group, talk over two sunny days and late evenings turned to possible creative uses for virgin Reform movements.
Given their looks, the mechanism must remain visible, but the motion work is to the (unremarkable) reverse. This led to discussions of projection clocks, or elaborate gearing to present time in the same plane as the movement, but to one side.
There was even intriguing talk of a large scale tourbillon. More detail than this presently remains closely held, but a competition to determine the best use was announced, to be decided in Mannheim in April 2015.
Reform is the order of the day.
This post was written by Peter de Clercq
In his most recent blog, Oliver Cooke discussed watches and clocks without hands as indicators.
Another example is the Mouse Clock, in which a mouse making its way up against a wooden board serves as time indicator. Its designer was inspired by the well-known nursery rhyme:
Hickere, Dickere Dock
A Mouse ran up the Clock,
The Clock Struck One,
The Mouse fell down,
And Hickere Dickere Dock.
The rhyme comes in various versions; this is the oldest, published in 1744 in Tommy Thumb’s_Pretty_Song_Book.
Could it be based on a real event: a mouse hiding inside a longcase clock, panicking when it struck?
In the literature I find only other explanations. One authority suggests it may be an onomatoplasm – an attempt to capture, in words, a sound; in this case, the sound of a ticking clock. Another relates it to the shepherds of Westmorland who once used ‘Hevera’ for ‘eight’, ‘Devera’ for ‘nine’ and ‘Dick’ for ‘ten’ when counting their flock.
Be that as it may, just over a century ago it inspired an American businessman, who was also an avid clock collector, named Elmer Ellsworth Dungan, to develop the Mouse Clock.
He initially just created one for his daughter, who loved the nursery rhyme, but then decided to take them into production. He took out patents and various models were manufactured.
They are nowadays prized by novelty clock collectors, so much so that we are warned to beware of reproductions, especially for what one dealer calls ‘Chinese knockoffs’.
Details, including several images of the mechanism, and a link to an animated photo of the clock in operation, can be found on these American websites: Antique Clock Guy and Fontaine’s Auction Gallery.
In 1966 the NAWCC published a booklet by Charles Terwilliger, Elmer Ellsworth Dungan and the Dickory, Dickory Dock Clock; there is a copy in the AHS Library at the Guildhall.
And speaking of mice and clocks, how about having some fun with the (grand)children with this on-line clock reading game. Read the time correctly and the mouse runs up safely to the cheese in the clock. Read it wrong and the cat gets the mouse.
This post was written by David Thompson
Many thousands of people today have stood amazed in front of the Astronomical Clock in the Old Town Hall Square in Prague, but I wonder just how many have managed to make sense of the dial. In modern times, perhaps it makes little sense.
The clock was made by Jan Šindel in about 1410, and from as early as the 15th century, the clock had a 24 hour dial which showed the so-called Bohemian Hours, a system in which the day began and ended at sunset.
This means, of course, that the 24-hour ring around the outside had to be adjusted periodically so that the 24th hour coincided with sunset.
In the early part of the clock’s life this was done manually, but later an automatic mechanism was installed to adjust the position of the ring. In medieval Prague, a knowledge of how long it was to sunset and the imposition of curfews in the city was useful knowledge. For instance – a simple glance at the dial indicating 19 hours tells you straight away that it is five hours to go before sunset.
As well as telling the time, the dial also has moving sun and moving effigies of the sun and moon, showing where in the zodiac they lie throughout the year. Useful astrological information.
The ecliptic circle with the zodiac signs and the sun and moon effigies rotate together once per day, but gradually over the course of the year, the sun and moon effigies with make a complete circle of the zodiac.
All this is achieved by some sophisticated gearing located behind the dial and driven by the clock mechanism in the tower. With the horizon circle with shaded buff areas, the periods of Aurora and Crepuscular, dawn and dusk are also shown,
Today, the clock is controlled by a more modern ‘regulator clock made by Romuald Bozek in the 1860s, but for the most part, the clock mechanism is still that which has been in existence from the beginning of its history.
Looking at the illustration here, you will see that the time is just a few minutes past 13 hours. On the fixed chapter circle the time is shown just before IX o’clock in the morning and hour 24 is just before 8 o’clock in the evening – correct for a July date. The sun is in Leo and the moon is in Aries.
So next time you stand in front of this amazing clock, you can really show off by knowing how to read the dial.
This post was written by Oliver Cooke
This watch has a display with digits formed of light emitting diode (LED) segments, seven for each numeral.
LED watches were first introduced in 1970 by the Hamilton Watch Company and were soon followed by liquid crystal display (LCD) watches. LED and LCD were by no means the first technology to enable digital displays however.
Before these examples existed the 'wandering hour' dial, something of a mash-up of digital and analogue time indication.
The hour numeral wanders, from the left-hand position (as viewed), up-and-over the semicircular aperture during the course of an hour. As the current hour ends and disappears behind the dial plate, the next hour numeral appears on the left.
We see 12:14 indicated on the illustrated example.
The system was invented in the 1650s by the brothers Tomasso and Matteo Campani from San Felice in Umbria, as a means to enable the time to be read at night (the numerals are pierced, allowing the light of an oil lamp to pass through from behind). This was very useful in the days before instant electrical lighting.
The wandering hour dial was also, occasionally, used on watches in the late 17th century, (but an oil lamp was not fitted in these!)
Finally, this watch also blurs the distinction between analogue and digital.
It has an LCD but, instead of digits, it has radial segments representing hands. This, however, requires 120 segments instead of the 42 needed to make up a standard six-digit digital display.
Together with the corresponding electronics needed to drive each segment, this means that these “LCA” watches cannot be made as cheaply as their digital counterparts. Perhaps for this reason they have never been popular, but they must have an adequate, if small, number of fans as they seem to have always (just) remained in continous production by one manufacturer or another since the 1970s.
I wonder how many of their fans, like I, appreciate them mostly for the futility of over-engineering, to achieve a result with LCD that is much more easily and better obtained with physical hands!
This post was written by James Nye
Things turn up. Back in 2006, when David Rooney and I were researching the Standard Time Company (STC), we planned a lecture at the Guildhall library.
The only surviving early clock we knew of had spent its life at the Royal Observatory—but out of the blue, days before the event, a Lund-synchronised dial clock turned up.
In the following eight years, that was it—nothing else—and then suddenly, through the kind agency of Keith Scobie-Youngs, The Clockworks acquired a wonderful addition a few weeks ago, in the form of an outsized fusée gallery movement, fitted with a massive Lund synchroniser.
The movement is by Thwaites, from the early nineteenth century, and signed elaborately by Metcalfe of 122 Newgate Street, London.
When STC went public in 1886, it listed its clients in the prospectus, and the very institution on which it was being floated appeared second in the list.
The accurate timing of bargains made by the jobbers on the London Stock Exchange was an important matter, and ‘the House’ was an early adopter of the new technology that provided hourly synchronisation of its clocks.
Remarkably, our new addition was one of probably several STC-synchronised clocks that populated ’Change, where it seems to have served for some time.
Each hour, a signal would travel from STC’s offices on Queen Victoria Street around a series of looped networks, energising the coils of the synchronisers. These were the ‘set-top boxes’ of their day, added perhaps many decades after a clock was first made—as was clearly the case with this clock.
The Stock Exchange synchroniser is particularly large, operating two small fingers that project through the dial, to correct the minute hand each hour. The long use of the device is evidenced by the deeply indented witness marks in the tab on the back of the hand, caught by the synchroniser.
Overall the movement seems rather outsized for the scale of the dial it ended up supporting—the large counterweight is much more than a match for the 15-inch minute hand.
Sometimes, it’s very hard for us to trace the environs in which our clocks spent their time—and to deduce whose lives they counted out. Thankfully in the case of this remarkable STC clock, there’s an old crank that can tell us a story or two.
This post was written by Peter de Clercq
In a previous post I included an opera scene, in which a woman mentions (sings!) that at times she stops all the clocks in her house. She dreads getting old and wants time to stand still.
One reader told me this reminded him of a poem by W.A. Auden which begins:
'Stop all the clocks, cut off the telephone.
'Prevent the dog from barking with a juicy bone,
'Silence the pianos and with muffled drum
'Bring out the coffin, let the mourners come.'
But here the motive for stopping the clocks is different. Someone has died, and stopping the clocks in the house of the deceased, silencing them, is an old tradition, similar to closing the blinds or curtains and covering the mirrors. The clock would be set going again after the funeral.
Some people believe stopping the clock was to mark the exact time the loved one had died. The subject was discussed here by members of the NAWCC, the National Association of Watch and Clock Collectors in America.
The French film Jean de Florette, set in the Provence between the wars, contains such a clock-stopping scene. The film is made after a novel by Marcel Pagnol, from which the following quotes are taken.
Jean, an outsider, inherits a house with surrounding land and hopes to make a living there. But two locals, who covet his land, secretly block a source, cutting off his vital water supply.
In despair, Jean uses dynamite to create a well, but he dies as a result of the explosion (chapter 37). The doctor, taking his pulse, 'listened for a long time in a profound silence emphasized by the ticking of the grandfather clock', but the man had died.
Then one of the two devious locals, who was in the room, 'crossed himself, walked around the funeral table on tiptoe, and stopped the pendulum of the grandfather clock with the tip of his finger'.
He then tells his comrade in arms 'Papet, I have just stopped the grandfather clock in Monsieur Jean’s house' – a way of saying: he is dead.
The three stills reproduced here are from that scene, which you can see in this short clip.
The clock is a typical Comtoise grandfather clock with a big flower pendulum.
This post was written by Rory McEvoy
Recently, I have been looking at the role of timekeepers in the history of science and whilst reading around the pre-pendulum era, happened upon a blog-worthy experiment conducted by Athanasius Kircher (1601/2-80).
He thought that the daily motion of sunflowers as they followed the Sun was caused by magnetic influence and thus inferred that they could be usefully used as a clock. As can be seen in his magnificent illustration, Kircher planted the sunflower in a cork pot and floated it on water, providing a frictionless pivot, and inserted a pointer through the flower to indicate time against the annular chapter.
Kircher noted that his clock was disturbed by the slightest of breezes and, when kept away from sunlight, it withered and its motion slowed. This, however, did not end the experiment. He tells us that he had the good fortune of meeting an Arab trader who happened to have amongst his aromatic wares a substance with similar horological properties to the sunflower.
The deal was struck and Kircher parted with his sundial signet ring for the horological stuff.
It has to be said that this episode is possibly a theatrical device to colour the account and introduce the use of sunflower seeds and root instead of the plant itself, but worth repeating – even if it’s just an excuse to show a beautiful horizontal sundial ring!
Today, we know that this diurnal motion is caused by sunlight and so Kircher’s clock could never have worked in the way intended, but one cannot help admire his ingenuity in applying a mystery of the physical world to tell the time. M. Becker’s 2011 time lapse movie shows that it is possible to use a flower as a twenty-four hour clock, but only in summertime at a latitude close to the north or south pole.