The AHS Blog

Journal Volume 35 Issue 1

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Just so you know how rich I am

This post was written by David Thompson

Today some people wear expensive watches partly to demonstrate their wealth. They either sparkle with diamonds or they impress with their complexity of mechanical magnificence. You might think that this is a new idea, but in fact this tradition goes back centuries to when the first watches were made in the early part of the 16th century.

An interesting example of this comes from the title page of Sir John Harrington’s translation of Orlando Furioso, (The Frenzy of Orlando, an Italian epic poem by Ludovico Ariosto first published in 1516.) Harrington’s translation, which appeared in 1591 was the first in English. The story contains politics, war, religion and unrequited love as well as fantasy and consists of forty-six eight-line verses in rhyme – quite a challenge for the translator.

Title-page from John Harington 'Orlando Furioso in English Heroical Verse', 2nd edition, London, 1607. (reg.no Prints & Drawings 1895,1031.288) © The Trustees of the British Museum
Title-page from John Harington ‘Orlando Furioso in English Heroical Verse’, 2nd edition, London, 1607. (reg.no Prints & Drawings 1895,1031.288)© The Trustees of the British Museum

On the title page of the work is an engraved portrait of Sir John proudly sporting a fine oval-cased watch with the Harrington shield of arms engraved inside the cover. The portrait is dated 1st August 1591 and bears the inscription ‘Il tempo passa’ and the legend that Sir John was thirty years old when the portrait was taken – time passes and this is a moment in the life of the author.

Portrait of John Harington from title-page to 'Orlando Furioso Reg.no. Prints & Drawings P,1.208 © The Trustees of the British Museum
Portrait of John Harington from title-page to ‘Orlando Furioso (reg.no. Prints & Drawings P,1.208)© The Trustees of the British Museum

A similar watch can be found in the British Museum collections, made by an immigrant Flemish worker in London, Ghylis van Gheele and here too, the watch sports a shield of arms, This time of the Giffard family of St. Andrew’s Abbey in Northamptonshire.

Oval cased gilt-brass verge watch by Ghylis van Gheele, London, 1589. (Reg.no. 1974,0718.13) © The Trustees of the British Museum
Oval cased gilt-brass verge watch by Ghylis van Gheele, London, 1589.(Reg.no. 1974,0718.13)© The Trustees of the British Museum
The movement of the watch
The movement of the watch

In late Elizabethan England what better way to show everyone just how wealthy and successful you were.

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Power madness

This post was written by Oliver Cooke

In a previous post I explained how mechanical clocks and watches work, with five elements – energy, wheels, escapement, controller and indicator. Let’s explore how some clocks and watches get their energy.

Mechanical clocks and watches employ kinetic energy, drawn from a built-in reserve – usually a mainspring (elastic potential energy) or a driving weight (gravitational potential energy). However, these need to be replenished, or wound-up.

We commonly wind-up a clock or watch directly, with kinetic energy from our muscles (which, before that, was chemical energy from our breakfast). In an automatic watch, a moving weight spins and winds it up as we move around.

In c.1765, James Cox made a clock that is wound by changes in atmospheric pressure. Similar is the Atmos clock, which has gas-filled bellows which expand and contract with changes in the surrounding air temperature and pressure – this movement winds the spring in the clock. This has been a very successful design – it was first introduced in 1928 and it is still being made. There was even a mechanical clock made to be powered by by an artificial heat source (see image).

A top of this dial is an “up-and-down” indicator showing how long the clock has left to run - sometimes known as a power reserve indicator or  “réserve de marche”.  Marine chronometer by Thomas Mudge, Plymouth, 1774 (British Museum reg. No. 1958,1006.2119)
A top of this dial is an “up-and-down” indicator showing how long the clock has left to run – sometimes known as a power reserve indicator or “réserve de marche”. Marine chronometer by Thomas Mudge, Plymouth, 1774 (British Museum reg. No. 1958,1006.2119)
The movement of self-winding watch showing the winding weight.  Jaeger Le Coultre, Switzerland, 1959  (British Museum reg. No. 1988,0409.3)
The movement of self-winding watch showing the winding weight. Jaeger Le Coultre, Switzerland, 1959 (British Museum reg. No. 1988,0409.3)
An Atmos clock.  Jaeger Le Coultre, Switzerland, 1947 (British Museum reg. No. 1986,1025.1)
An Atmos clock. Jaeger Le Coultre, Switzerland, 1947 (British Museum reg. No. 1986,1025.1)
The bellows that wind the clock are in the large barrel behind the dial.
The bellows that wind the clock are in the large barrel behind the dial.
Table clock with “Weingeistaufzug” (“alcohol elevator”).  The black bar at the bottom-left is an electric heater - it heats the pink-coloured alcohol, causing it to rise to the upper vessel, which then drops under gravity, driving the mechanical clock movement.  Is there any form of energy not involved?!  Karl Jauch, Schwenningen c.1940 (Deutsches Uhrenmuseum Inv. 50-4135)
Table clock with “Weingeistaufzug” (“alcohol elevator”). The black bar at the bottom-left is an electric heater – it heats the pink-coloured alcohol, causing it to rise to the upper vessel, which then drops under gravity, driving the mechanical clock movement. Is there any form of energy not involved?! Karl Jauch, Schwenningen c.1940 (Deutsches Uhrenmuseum Inv. 50-4135)
A rack clock - here the weight of movement and case of the clock serve to provide the driving weight.  To wind it, the clock is simply moved to the top of the rack, and it and it drops over the bottom over the course of a day.  Charles Mabille, Paris c. 1775(British Museum reg. No. 1958,1006.1965)
A rack clock – here the weight of movement and case of the clock serve to provide the driving weight. To wind it, the clock is simply moved to the top of the rack, and it and it drops over the bottom over the course of a day. Charles Mabille, Paris c. 1775(British Museum reg. No. 1958,1006.1965)

Electrical clocks and watches employ electrical energy. We might provide this by putting in a fresh battery (which is a reserve of chemical potential energy), although sometimes the battery is rather larger than the clock it powers!

Mains powered clocks often do not have a built-in energy reserve and so these are reliant on a continuous supply to keep going. Solar powered clocks and watches use solar panels to convert light to electricity, which then charges a battery – this reserve is essential as the power source is not reliable – e.g. day and night.

Smiths 'Sectric' electric mantel clock.  The clock is not only mains powered, but its motor is “synchronous” i.e. its speed depends on the frequency of the alternating current and this controls the rate of the clock.  This is very reliably as the mains frequency is very stable.  Smiths English Clocks Limited , London, c.1950 (British Museum reg. No. 2008,8022.1)
Smiths ‘Sectric’ electric mantel clock. The clock is not only mains powered, but its motor is “synchronous” i.e. its speed depends on the frequency of the alternating current and this controls the rate of the clock. This is very reliably as the mains frequency is very stable. Smiths English Clocks Limited , London, c.1950 (British Museum reg. No. 2008,8022.1)
The mechanical pendulum of this Synchronome master clock is kept going by an electrical device.  Synchronome Clock Company Limited, London, c.1948 (British Museum reg. No. 2008,8023.1)
This Synchronome master clock is electromechnical – its mechanical pendulum is kept going by an electrical device. Synchronome Clock Company Limited, London, c.1948 (British Museum reg. No. 2008,8023.1)

So, those are a few examples of how clocks and watches can obtain the energy they need. Of all the types of energy I can think of, only sound and atomic energy have not been not used to directly power clocks and watches. As to how they exploit the energy… well that is another story altogether… maybe for a later post!

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It’s for the birds

This post was written by James Nye

Some pigeon racers were cheats. This was the shocking brief given to the Skymaster Clock team in the 1950s when refining their latest patent racing clock.

It was a serious business for the 100,000 registered pigeon fanciers in Britain, and rigid standards were enforced. Defeating the few cheats involved some inspired horology, and when I heard how clever the solution was, I wanted to share it here. But first, let’s understand the basics.

The Skymaster Ghost pigeon clock, c.1952
The Skymaster Ghost pigeon clock, c.1952
Movement in base, stamping mechanism in centre
Movement in base, stamping mechanism in centre
Clock movement
Clock movement
Printing dial
Printing dial

The Skymaster clock contains a 7-jewelled platform escapement movement, coupled to an inked ribbon stamping mechanism (like a time-recorder) which presses a paper tape against an internal mirror image dial (in relief), recording the time a returning pigeon’s identifying ring is inserted.

Races are won by seconds. Pigeon clocks are meticulously checked and every option to cheat is blocked. But unscrupulous fanciers had come to believe that platform escapement clocks could have their rates meaningfully altered, for example by swinging the clock in the same plane as the balance, so that they might both retard the locked clock (ideal before the pigeon arrives) and advance it (needed once the pigeon is back) to get it back to time before being examined by an official.

Dolometer case
Dolometer case

The effectiveness of these methods is uncertain but, nevertheless, Eric Moss and Bruce Alexander of Smiths were compelled to devise a brilliant solution for the Skymaster – called the ‘Do­lometer’. They based it on an electro-mechanical car clock, in which typically an inverted-Sully escapement (electrically driven) advances the train. See an animation here. They removed the magnetic drive, and relied on the overall motion of the clock to drive the Dolometer – thus the dial reveals the degree of any shaking.

The ‘Dolometer’ in situ
The ‘Dolometer’ in situ

Calibrate for ‘normal’ activity (the natural joggling of a journey home to the loft, plus a margin for error) and if the Dolometer shows an excess, you have detected a naughty pigeon fancier’s attempted fraud. Bruce Alexander carried a dolometer for days – even cycled with it – to work out what a normal reading would be.

Reset screw. Clock up more than ‘3’, disqualification
Reset screw. Clock up more than ‘3’, and you’re disqualified
Balance in foreground, driving the dial to rear
Balance in foreground, driving the dial to rear

This seems to me to have been inspired thinking on the part of the designers. And it inspired me to acquire a Skymaster so that I could dismantle and photograph it for you.

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