   POUVILLON RESTORATION PROJECT - November 2011 Proposed designs to restore the zodiac precession, the year indicator ring, the orrery demonstration crank and replace orrery planets and their counterweights 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. 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. There is strong evidence that three complications which are currently missing were present within the original movement. The first is the precession of the zodiac which occurs over a very long 25,806 year cycle. The second is to replace the missing year indicator ring, and the third is the ability to manually demonstrate the orrery in fast speed. Below we show our proposed designs to recreate the parts needed to restore these complications that we believe the Pouvillon clock had originally. Next we turn to replacing the missing planets in the tellurian and the orrery. Finally we explore, pending any further information, what Pouvillon may have used the extra attachment points on the tellurian and orrery for.
We now turn to the
restoration of what we believe are the missing components for three
complications. Here we have Buchanan’s design for the first complication,
the lower zodiacal ring to rotate once per 25,806 years to give the
indication of the
precession of the zodiac.
In a 1953 Paris newspaper article Pouvillon states that the zodiacal ring is
made to rotate, through a set of twelve reduction wheels, once per 25,806
years. This is again repeated in an article for the Association Nationale
des Collectionneurs et Amateures d’ Horlogerie Ancienne (ANCAHA) in the
1985 Summer issue written by Bernard Miclet. There is no doubt that the
lower zodiac is designed to turn, and when measured against the fixed upper
ring which is calibrated in markings to make up 3600, would
readily lend itself to this function. There are a few open holes where such
a system could have been mounted.
Here we
have a dilemma. In the few photos we have to date, all of which were made
after the death of Mr. Pouvillon in 1969, there is no evidence of this wheel
work being present. Did Pouvillon actually complete this function, or was
this never attempted or completed?
We propose to recreate this function and use only those holes that
are currently open to attach the wheel works. Nothing of the original
artifact will be altered and everything will be fully reversible. Our system is
designed to be completely hidden beneath the zodiac ring since we have no
evidence so far of how or if Pouvillon made this. We also use
twelve wheels to achieve the required reduction. All wheels will be made in
the manner of Pouvillon’s own wheel design.
This
diagram depicts our design to recreate the second missing complication
component which is the calendar ring year indicator in the tellurian dial.
In Janvier’s tellurian, which this certainly was at one time, this
indication was shown as a set of numbers from ‘00’through ‘99’on an annular
ring and seen through a small square aperture in the porcelain dial just
after the month of January. On the dial there is already a ‘1’. Followed by
the aperture. In Janvier’s unaltered tellurian, of which we have good
photos, there was a ‘1’ followed by an ‘8’. The one is fully backed onto the
enamel in the same fashion as all the other black lettering, but the eight
looks to be much lighter, almost as if it were removable. This would make
sense as that tellurian was made around 1790 and if the seven had been
permanent the year indication would have been good for only ten years. The
square aperture is now filled in and all evidence of the annular ring is
missing. It seems that Pouvillon was anxious to cram as many complications
as he could into his clock and this complication is not duplicated anywhere
else in the clock. It would seem that he would want to preserve this
indication. So, absent evidence to the contrary, we propose to reinstate
this. For more on this complication and the history of the origin of this
tellurian see the August 2011 installment.
A discussion
about the origins of the tellurian assembly.
As stated before, this will be fully reversible with no permanent changes to
the artifact.
Both of the
proposed reinstated complications discussed above must somehow be driven.
The zodiac ring could be driven by a direct gear connection. The calendar
ring, however, must be stepped, or ‘clicked’ once per year so the correct
number appears in the aperture window immediately and stays there until the
next annual change is needed. A direct gear connection to the zodiac is not
possible without alterations so we opted for both of the systems to be
stepped. For the zodiac ring this makes no difference due to the extremely
slow rotation. In fact it’s unlikely one would notice any movement within
one’s lifetime. The long arm below the mechanism extends rightward, beyond
and below the zodiac ring and turns upward a small distance just beyond the
ring’s perimeter. This small ‘paddle’ engages, or is pushed by the pointer
which indicates the zodiac sign and is located opposite of the pointer which
is below the Earth on the tellurian that reads the degrees on the upper,
fixed ring. Therefore, as the tellurian boom swings past the paddle each
year, this mechanism will step both the zodiac and calendar rings. I had two
problems with this design. The first was the fact that we have no evidence
of any external paddle being used. Secondly, the zodiac pointer will have to
be beefed up to do its job of pushing the paddle lever, a change to the
artifact as I’m convinced that this pointer is original.
This is an alternative to the stepping mechanism described above. Here we eliminate the external paddle lever. Instead the stepper is driven off the uppermost planet’s arm as it swings around; that planet being Mercury. Shown here are the wheels necessary to convert Mercury’s annual rotation of 0.24 years to an annual step for the calendar ring. The feed to the zodiac ring remains as in the prior diagram. There may be a bit of evidence to back up this design. In the one photograph we have of Pouvillon with his clock, and it is a poor one to indicate detail, we can see a small bit which could be a pin to catch the arm of Mercury. Again, barring new evidence all is just conjecture at this point. See blow up of photo section. In this enlargement there is definitely something there below the zodiac ring that is no longer present and could have been something used to drive the zodiac precession.
A careful examination of the base plate supporting the orrery superstructure showed witness marks where two cocks were originally mounted (1 and 2). In addition there was a space below the orrery drive pinion where an additional part was mounted to that arbor (3). Using this information we will restore, again without any alteration to the clock as found, the demonstration winding crank assembly for the orrery. Pouvillon created this clock as an advertisement for his skills. He certainly would not have missed the opportunity to have has a stunning demonstration of his orrery. These diagrams show the proposed system. Since the orrery is driven from the strike train, the crank will disconnect the orrery from that train when the winding key is inserted and while the orrery is in the demonstration mode and then reconnect the orrery when the winding key is withdrawn.
Pouvillon-65-001.MP3. Photo 65 001.
This series of photographs shows the procedure in making the ball joints for
the elbow joints for each of the planets on the orrery. Here we have a brass
rod held in the collet on the lathe and we’ve reduced it to the overall
diameter of the ball. Photo 65 002.
Here we have the ball turning attachment fitted the lathe and preparing to
take out first cuts.
Photo 65 004.
We have the ball turned complete and we now have to machine the actual
parallel portion of the stem. Photo
65 006.
Here we are machining the parallel portion of the spigot on the ball.
Photo 65 007. Busy parting off
the ball and its spigot from the parent material.
Photo
65 009. Here we’re holding the
ball by the spigot in a collet in a vise and at the top of the picture
you’ll see the drill bit ready for drilling the hole to produce the vertical
support for each planet.
Photo 65 011.
Here we’re about to drill the hole for the vertical wire for the planet.
Pouvillon-65-019.MP3. Photo 65 019. You can see a split collet to
hold the ball with the end of the spigot projecting out the front of the
collet. This is placed in the lathe in a larger collet which enables us to
hold the ball by the spigot without damaging our nicely turned sphere.
Photo 65 020.
Here you can see the split brass collet in the main
collet on the watchmaker’s lathe and the end of the spigot projecting ready
to have the center hole drilled in it.
Photo 65 021. About to start
drilling the hole for the horizontal wire that supports the whole arm.
Photo 65 025.
The completed elbow joint and the seven extra balls for the other planets.
These will later still be reduced in size to make
them less heavy looking. We now turn
to the making of the planets for the tellurian and the orrery. From the one
photo we have of the clock before Pouvillon’s death it looks like all of the
planets were made of a white material and given the time of manufacture we
believe these were probably made of ivory. A source of legal elephant ivory
material was located and is used for the planets as well as the winding and
orrery demonstration key handles. We have recreated these to the same size as we could best
determine from the one existing photograph.
The first
photo shows the initial line up of the planets and their relative sizes as
compared to the ruler. The next photo shows the initial
setup.
These two
photos show the planets as we were best able to determine Pouvillon would
have designed them. Notice in the second photo that there still is an empty
attachment point opposite each of the planet’s attachment points on each of
the orrery collets, see arrow. We believe that these empty attachment points
could have been used for a counterweight to the planets. The problem is that
this same design is used for the inner planets where there would be no need
for this. Therefore, we have decided to again design a use for these that
are totally reversible and have no effect on the original artifact.
The next
several photos show what we decided to use the empty attachment points
available on all of the planet collets for. These would indicate the
zodiacal sign for each planet and these signs would be read off of the
zodiac dial to better determine the planet’s position within the zodiac, see
red arrow.
The paper
squares represent the planet zodiacal signs as they move through the zodiac
as depicted on the lower zodiac ring. The next photo shows an overview of
this. The next photo shows the initial design for the planetary zodiac sign
next to the trial paper models.
The video shows our initial trial demonstration of the orrery with its newly mounted planets
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