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Disassembly of the tellurian and orrery subassemblies

I have asked Buchanan to provide what I call a 'forensic' report. That is to record his observations as he goes along. I will provide the .MP3 audio file for each segment but just in case your security settings will not allow you to open this file I have also transcribed each session. My additional comments will be inserted into the text from time to time and this will be in red text. Buchanan refers to each photo by the number of that photo which can be followed by each photo above the captioned text. The .mp3 audio file will appear in blue text.MP3. Click on this text and you can then follow along with the audio file by scrolling downward through the photos as they are narrated one by one in the voice of the restorer.

In this segment we completely disassemble the tellurian and orrery subsystems.

Below we deal with the disassembly of the tellurian and orrery subassemblies. These comprise 81 wheels.

Buchanan now turns to the tellurian and orrery. Pouvillon-57-001.MP3. Photo 57 001. This shows the strike fly. What I’ve tried to do here is investigate the possibility of rotating the fly 1800 to see whether or not we could have the drive weight for the Easter calculator suspended above the base of the clock but as you can see the upper blade of the fly makes contact with the horizontal frame pillar. So we can see this is impossibility. There’s also no sign that this was feasible due to a locating pin on the fly fan pillar which prevents it from actually mounting this way. I had to knock out the taper pin to even stand it here. So this is not a possibility. Pouvillon-57-004.MP3. Photo 57 004 showing the 3600 marked dial which remains stationary while the orrery and the tellurian, as such rotate. This definitely does not precess, with the signs of the Zodiac. Photo 57 005 another view of the drive mechanism on the Earth side of the tellurian.

Photo 57 006. A gear being removed involved with the drive to the 3600 ring dial. Photo 57 007. Another view of the top of the tellurian. Photo 57 008. Removing the two tubes that carry Mercury and Venus.

Photo 57 009. The underside of the orrery showing the main gearbox which drives the outer planets. And also at the lower end of the tube you’ll see the bevel gear which drives the three smaller dials mounted on the left hand side base of the orrery; the name of the month, the zodiac sign of the month, and the season. Also included is the front leap year dial. Photo 57 010. Just a side view of the main orrery mechanism. It’s interesting to note that this shown in this photo controls the planets outside the orbit of the Earth and is totally self-contained and has nothing whatsoever to do with mechanically with the tellurian and the two inner planets. Photo 57 010. Another view of the main orrery mechanism.

Photo 57 012. This is the click that holds the Geneva-type feed wheel in position while the feed pawl is out of contact with the wheel; which is fed once every 24 hours. Photo 57 013, is the main base for the orrery. In the center we have the steel stationary arbor on which the Sun is mounted. Then we have an inner tube which is also stationary and an outer tube which is also stationary. Also we can see the seven lower dials around the edge of the base and projecting off to the right we have the moon drive that comes up from the dial and this does one revolution in twelve hours. And we have a 48 toothed worm wheel which you can just see in the center, the lowest gear in the center of the orrery base. Photo 57 014. Here we have the main tellurian mechanism coming away from the dial.

Photo 57 015. We have an inner tube and its gears being removed from below the orrery. These gears are on the main tellurian drive. Photo 57 016. The stack of concentric tubes for the outer planets and the main tube on which they all mount. Photo 57 017. This is the main tellurian drive tube and the five gears that mount on its base and the associated spacers.

Photo 57 018. This is a detailed photograph for reassembly and orientation purposes. Of interest to note is the solid gear in the center of the picture appears to have a chrome or nickel plate finish on it. Photo 57 019. Here we can see the plated finish on the two left handed gears also we can see the numbering, or the tooth counts that are punched into some of the gears. On the right hand side we have a very crude spacer-washer. Photo 57 020 is the final washers in the gear stack. We can see in the center, obviously, the very crudely made spacer-washer and on the big brass spoked wheel we can see 203 punched into the hub and also on the right hand side we can see the screwed sleeve that claps the whole assembly together.

Photo 57 021. The six tubes that make up the outer planets, interestingly enough this orrery goes right out to Pluto. Photo 57 022. Another view of the workbench with the set of tubes in the foreground. Photo 57 023. Some of the components disassembled so far.

Photo 57 024. A view of the cloaked, square hole in the enamel dial. Pouvillon-57-025.MP3. Photo 57 025. Here we have the main enamel dial for the tellurian and of note, of course, is the filled square just behind the end of January. Photo 57 026. Here we have a hairline crack at April.

Photo 57 027, another crack. Photo 57 028, another crack. Photo 57 029. A rear view of the dial, unfortunately there is no apparent maker’s name or enameller’s name on the back of the dial. Of interest right at the bottom at about 28 minutes to, we have the back end of the dial filling, or the plug for the square calendar hole.

Photo 57 030. Another view of the plug for the calendar square. Pouvillon-57-033.MP3. Photo 57 033. A close up of the plugged hole in the calendar dial. Pouvillon-57-035.MP3. Photo 57 035. An interesting photo of an inserted tooth in the rim of one of the planet teeth. As you can see there’s a silver solder fillet in the corner of the spoke and if you look carefully you can see the inserted tooth in the rim. Whether this was a damage or a constructional accident, or a repair, it’s hard to tell.

Photo 57 036. A view of the other side of the wheel and the inserted tooth which shows a little more clearly. Another hypothesis could be that Pouvillon realized he mis-cut the wheel and was one tooth short! This would be a logical place to split the wheel for the insertion of the extra tooth since the wheel cross provides a convenient place to shore up the repair as was done.   Photo 57 037. This was just a photograph to blow up to obtain a tooth count on a small gear. Photo 57 038. A photograph of another wheel to obtain a tooth count. This gear would be perhaps 1/8” in diameter.

Pouvillon-58-026.MP3. Photo 58 026. Is an underside view of the disc that supports the enamel tellurian dial. We have on the lower left hand side the friction-tight pinion mount for adjusting the Easter related feasts. We also have an empty hole, an elongated hole next to a screw head. And we have a tube with a slot that slides over the partially unscrewed, screw. The purpose of this tube is to carry the outer planet nest of gears. The four spoked wheel, I believe, is a Janvier component. The brass is scarred and shows far more signs of wear than Pouvillon’s own construction. Photo 58 027. An empty screw hole you can see there’s bruising around the hole on the right hand side where the screw had tightened against the brass wheel. Photo 58 028. Is the opposite side of the upper side of the wheel and the flange into which the missing screw mounts.

Photo 58 029 is the collar and friction-tight pillar that carries the feast adjusting pinion. I believe that this is a Pouvillon addition due to the hex-nut type construction. Photo 58 030 is part of the main orrery frame construction. Photo 58 031. Another view of one of the orrery frames. Of interest to note on the left hand side is that this whole assembly is numbered so as we proceed up the two main octagonal support pillars each mating surface has a consecutive number.

Photo 58 032. Is a gear I believe made by Janvier, fitted to a tube by Pouvillon. Photo 58 033, is the outer ring of the tellurian dial. We have the domed base pillar which is actually the mount for the enamel dial. The dial leg that goes into the hole and is clamped by the screw from the left hand side. Of interest to note it has two identification punch marks next to it and also we see the loose screw head that holds the rim of the engraved silver zodiac ring which allows the ring to move or to be adjusted by comparison to the center brass disc. These screws have a lock nut underneath so they can be held in a loose position to provide a certain amount of freedom of movement. Photo 58 034. Another view of the zodiac ring holding screw and a dial pillar. This indicates that the zodiac ring was designed to rotate.

Photo 58 035. The second empty hole in the zodiac ring disc. There’s no apparent use for this hole. Photo 58 036. Another photograph of the frame assembly for the orrery. Pouvillon-58-039.MP3. Photo 58 039. Here we have the complete orrery frame assembly. As you can see we have the three concentric tubes that are all rigidly mounted stationary and do not revolve.

Photo 58 040. A closer view of the frame construction. Photo 58 041. Another photograph of the frame construction. As you can see each of these tubes are fitted to a flange which again is mounted hard on to a frame. Photo 58 042. Here we have a view from the top of zodiac ring support dial. The brass four spoked wheel, I believe, is a Janvier product and we can see on the outer rim at approximately 10 o’clock an empty hole. We can also see various blemishes in the actual brass. At 9 o’clock near the center we can see two identification center punch marks and we have the four screws which enable the zodiac ring to be moved. Now if you look carefully you can also see score marks from where the ring has been moved.

Photo 58 044 is a photograph of the various components making up the orrery. As you can see there is still a substantial amount of dismantling to occur. The next two photos show the disassembly of the tellurian boom.

The upper five photos show the tellurian boom completely stripped of components. This is Pouvillon's design for this component with the wheel works and dial by Janvier.


The first photo shows all of the components we believe to be by Janvier. All of these parts relate to the tellurian. The second photo are components by Pouvillon. The boom assembly is not present. These share some components with the tellurian and cover the entire orrery.


The first drawing shows the orrery for the outer planets of Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. The second drawing shows the orrery details for the inner planets of Murcury and Venus. 


The first drawing shows the tellurian depicting the Sun, Earth and moon system. The next drawing depicts the seven small dials that surround the tellurian/orrery superstructure's base. The left bank of dials as seen from the front of the mechanism comprise the strike indicator (unequal numbered dial), the zodiac sign for the day, the day's common name. On the right bank are the zodiac sign for the month, the month's common name and the four seasons. The front dial is the leap year indication.  

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