The following represents a list of links to what I think are great clocks. Some I'd like to build while others I'll likely never build but I simply admire them for their originality, creativity & magnificent execution. I think they represent a wonderful array of the many different ways that the passing of time can be told.

A Forged Iron Astronomical Clock

This is a longstanding dream but alas such an undertaking I'm not sure I'll ever achieve it. The goal is to build a scaled recreation of what I believe the Wallingford clock at St Albans was like. This has been done in past (such as above left) but I believe there are significant differences in several sections and no attempts which show the planetary gearing.

The vision is one of of finely forged and ornate iron workings (left) coupled to a geocentric anaphoric face which displays the heavens above. The picture on the right shows a clock face which is is likely loosely similar however it is *not* anaphoric. The anaphoric mode of display is very old going back at least to the water clock in the Tower of the Winds i.e it predates the astrolabe. Unlike an astrolabe on an anaphoric display it is the stars that move behind a frontal wire reference grill.

I would like the ironwork to be about 2ft on each side and mounted on a white oak frame. At such a scale there will be an issue with the period of the foliot (it will be too fast) however that is a minor workable point which does not concern me greatly. Even Richard himself was not greatly concerned about the clock section itself for he only describes it briefly in passing. The essence of this clock is in the mechanisms used to develop accurate reproduction of the celestial motions and in the dial itself where they can be interpreted.

I think it would be magnificent to look at the ornate display of the clock and then step outside and see the predicted reality in the heavens above whether that be a sunset, a phase of the moon, a certain star filled night, a planetary conjunction or even a solar eclipse. It would also be wonderful to be part of the over 2000 year old quest to model the heavens.

A Kinetic Wooden Clock

I still have a desire to make a wooden clock despite my initial set-back. I started that clock before I really understood the basics of clock making but it taught me a lot about the fundamentals. Since that time I have seen much along the way and one man's work seems to exemplify the themes I'm looking for in my next attempt and that is the work of Jim Borden. Here is a tremendously creative man who blurs the line between clocks and kinetic sculpture resulting in animated timepieces that capture the imagination and entertain the observer.

Part of the key is in the large escapements. Escapements are fascinating to watch yet in most clocks they are buried within the clock and, even if not, are often so small that many of the subtle actions can't be noticed. Being wood Jim's clocks are large with the escapements being a sizable percentage of that large size. Because they are large they are often tranquilly slow moving and all the interactions can be seen.

More of Jim's work can be seen on his homepage "Timeshapes"

A GPS Controlled Nixie Clock

This is now essentially completed and can be seen here

A Detached Escapement Clock

What is a detached escapement clock you ask? It is an attempt to achieve a free pendulum. A clock where the pendulum is unencumbered as much as possible from the escapement and time-train gearing. Above is a delightful example built by Martin Burgess. In this case the escapement is a variant of the Hope-Jones escapement. This clock has a massive, long pendulum. Attached at the top of the pendulum is a very light little "hooked" arm which pulls a tooth of an unloaded ratchet-like count-wheel on each swing (see photo on right). As the pendulum swings back and forth the only thing that happens on the clock is the count wheel advances. There is no other gear movement at all. After 30 counts there is an extra deep tooth on the count wheel which causes the hook arm to fall a little lower and release a long pivoted weight arm. The weight arm then falls onto a rod attached to the pendulum but the weight is straight down so there is no effect and the pendulum continues its swing. Eventually the pendulum swings far enough that the weight arm slips off, however, the weight arm has a 45° angled plate on the end and thus as it slips off it imparts a sideways push to the pendulum, keeping it swinging, before it completely falls away. After falling free of the pendulum rod the weighted arm then releases the time train (all the weight driven gearing in the clock) which then start to speed up. When the gearing is released and starts to move it then resets (lifts and latches) the weight arm back to the initial position. In doing so the net movement of the time train is 1 minute. After the soft "click - ssss - clunk - whatchung" sound of this event the clock then, for the next minute, goes back to quietly counting out 30 swings of the pendulum. Hence most of the time the swinging pendulum it is not really attached to the clock.

If you ever see such a clock it is such a wonderful piece of kinetic sculpture. The fact that it is a very accurate timekeeper only adds to the magnificence. The time and day of the week can be read off the aluminum pointer on each wheel. I love the skeletal nature of it. Unlike many "box with dial" regulators this one has flair!

A Gitton "Time Flow" Clock

Wow! Here's a different idea altogether. Bernard Gitton of France came up with this concept of an accurate water powered clock. The only commonality with a conventional clock is the pendulum. The pendulum on a Gitton Clock has a largish spoon attached to it at 90° near the top. Water is dripped into it from a reservoir above. This adds an offset weight to the pendulum giving the pendulum energy to swing sideways. When it moves sideways the attached spoon tilts and pours the water out to an open siphon below. This siphon is the first of a cascading series of ever larger siphons below which, in essence, work like a "binary" counter (the term binary is used for familiarity, this concept could count by threes or more instead). When the pendulum spoon has poured 2 spoons of water into the top siphon it fills and the water then siphons to the larger siphon below (the top siphon has now counted 1, 2 pendulum swings) causing the second siphon to now fill half way up. When the top siphon has siphoned twice the lower siphon fills up and the larger volume of water then siphons out to an even larger third siphon below (the clock has now counted 1, 2, 3, 4). This is repeated several times with a cascading series of siphons below. These can be seen left of center of the clock in the photos above. When all the siphons fill up after 2 minutes they all siphon out (starting at the top and proceeding sequentially to the bottom). The water leaving the all the siphons to a lower reservoir creates a vacuum which pulls a premeasured volume of water to fill the first "bulb" of the minutes column (on the right side of the clock in the photos above). Similarly when the minutes column fills up on the hour it too siphons out and creates a vacuum which pulls a premeasured volume of water to fill the next "bulb" of the hour column (on the left side of the clock in the photos above). They are apparently a delight to watch at noon as the whole clock will sequentially siphon into the lower reservoir until it is empty. There is a hidden pump which takes water from the lower reservoir to maintain an adequate level of water in the upper reservoir. The time indicated in the left photo is 1:32 while in the right it is 2:22. If you are interested in the details of its workings I would direct you to the Bernard Gitton's Liquid Science page. He apparently built some 2m tall versions but I was unable to find any for sale. I inquired of a glass blower many years ago as to how much it would cost to make a 2m version and was given a guesstimate of $4000.

A Radiometer (Light) Powered Clock

This is one that I became aware of only last year (2002). It designed by Marcel Bétrisey of Switzerland, and is called "The Chronolith" and is the product of a very creative person. It is certainly the most original horological idea I've seen in a long time. The pendulum is pushed to and fro not by falling weights, springs or motors but rather by the flashing of lights. It is based on the radiometer (photo below) effect.

Rather than the rotary motion of a classic "bulb" radiometer, on this clock, when a flash of light hits the dark panels on one side of the lower part of the pendulum the radiometer effect imparts a linear sidways push to the pendulum. A central IR detectors senses the passing of the pendulum and causes the lights on the other side of the pendulum to flash, and, it additionally imparts an electrical pulse to the top mounted clock movement which increments the time (approximately 1 sec as determined by the pendulum). The second flash of light slows the pendulum down and then "pushes" it back the other way where again the IR detectors sense the passing pendulum and the cycle is repeated. In order to achieve the radiometer effect the pendulum is mounted inside a tube containing a high vacuum. This has the side benefit that the effects of air on the pendulum are essentially negated. From the data logged so far it is a fantastic timekeeper.

I believe this is another marvel that will go in the history books. Enjoy!

A Foucault Pendulum

This has now been started and can be seen here

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