
The orrery as received was missing two
pinions which are needed to drive Jupiter and
Saturn planet arms. I had these made for the
project, first photo. As illustrated in the second photo
these would be mated to what I call the 'drive
cone'. All the wheels and pinions are joined.
The lowest and largest wheel receives input, the
next three wheels and two pinions are for
Mercury, Venus, Mars Jupiter and Saturn. The
Earth/Moon armature are driven separately.

The pinions installed, first photo. I do not know why
the supplier used a brass pinion, but everything
moves so lowly at this point of the mechanism
that it really doesn't matter. Notice how the
drive cone meshes with wheels of an opposite
size, in other words the smallest pinion drives
the largest wheel and so forth down the
five wheels of the cone. Of course this is the
way the planets orbital periods are correctly
depicted since the periods get longer as one
moves away from the sun. This pairing is made
more apparent in the second photo, taken after
the orrery was polished.. Fortunately the
concentric tubes were undamaged so they fit
perfectly.

One of the stars used to represent the planet
of Mars was missing. A computer group I belong
to gave some interesting sources to look for a
replacement. To be honest I was skeptical that
I'd find a close match, but luckily there was a
perfect match in as far as the star profile,
however it was only a half thickness, whereas
the original was mirrored on both sides. This
was a simple procedure to glue together and use
the same glue to attach it to the armature.
Soldering would be the more traditional way, but
I thought that no matter how careful one could
be there would be a tiny silver seam around the
edge.
The result was a very good match that could
only be improved on if I were to locate, or cast
a star. Casting was not possible as this is a
skill I do not have, nor want to practice for
one star! Casting would also have required the
removal of one of the other original from their
armature and they looked to be soldered in,
again not wanting to risk damage by unsoldering
and then re-soldering. The armatures were
originally gilt and while somewhat worn, the
gilding was evident.

About half of the screws were very corroded,
in fact the only screws not corroded were those
that were under the orrery table and the orrery
support plate. I like to keep things as original
as possible, however if a screw was originally
blued and is corroded beyond what looks
reasonable I will re-blue it. Bluing is a
simple, straight forward process for small
parts. Notice that I did not use an abrasive to
make the surface perfectly smooth. I did not
want the screw to look new, so I leave the
pitting in place, but make sure the pits are
clear of any residue.

At the right color the screw is quenched.
Depending on the look I want I may leave it as
is or rub it around in a lightly oiled rag.

Once a part is polished I then use latex or
cotton gloves. I'm interested in trying the
finger coverings as this avoids the sweat that
occurs with latex after a while, and cotton
gloves are fine for larger parts and easier to
remove, but small, delicate parts tend to get
caught in the weave where an accident could
happen.

Here the movement is finished. The arrow
points to the arbor that has a small hole
through which one end of the silk suspension
thread is tied. The section which extends past
the plate is square to accept a tiny key. By
rotating the arbor one can change the rate of
the pendulum.
Here is where an interesting story begins. As
found the arbor was located here. I was a bit
concerned that it freely rotated so how would it
hold its position with the weight of the
pendulum pulling on the thread wound around the
arbor? I set that concern aside for the moment.

In the first photo we have a side view to
show where the rating arbor is located, black
arrow. The next photo was kindly provided to me
by the curator of the clock collection belonging
to the Worshipful Company of Clockmakers. They
have in their collection and I has seen in
person, a clock nearly identical to this in
2011. That collection is now housed in the
British Science Museum. One can see that the
clock frames are virtually identical as are the
planting of the wheels and orrery demonstration
gear drive. Note the white arrow showing the
rating arbor in the same place. The is likely
the correct spot for this style of celestial
orrery. There are many types and these will be
compared and contrasted on the next page.

The first photo shows a rear, left
three-quarter elevation of the movement. Again
the black arrow shows the end of the adjustment
arbor. Look carefully where the arbor is
positioned with regard to the gilt dial
surround. It is hopelessly blocked by the
surround as is obvious in the second photo.
Remember the anomalous holes pointed out on
the prior page and how only one set were
mirrored on both the front and rear movement
plates? The second photo shows the hole on the
front plate and how it neatly fits in the open
space between the two arched leafy branches.
Someone had also punched curious triangular
indentations around the hole.

I then disassembled the clock and place the
adjustment arbor in the new location, it fit
perfectly and the punched hole in the front
provided just enough friction to keep it from
freely rotating. So in order to keep the
adjustment function that arbor was moved. Why in
the name of all that is proper, didn't the
person punch the hole in the rear plate instead
of leaving a set of ugly punch marks on the
front? I now know what the original arrangement
was. So the clock was made with the adjustment
arbor hole just above the dial, but at some time
before delivery to the customer, the dial
surround was added and the adjustment arbor
located higher up to accommodate this option. The two cheese-head
screws at the top of each plate were severely
corroded and re-blued. Fortunately the gilding
on the dial surround was in very good condition.
Here is one area where I decided to make a
change. To cover those ugly punch marks I took
one of the stars I had left over and attached it
to the square end of the adjustment arbor, thus
hiding the punch marks and giving continuity to
this fix with the stars in the orrery. The
attachment is fully reversible.

These photos show the structure of the dial
and gilt surround, In the first photo the black
arrows show where the dial feet are. The two
arms are attached to a small plate that has a
hole which fits over the dial foot. Those arms
reach upward to attachments under the orrery
support plate.

The first photo shows another celestial
sphere clock with the same gilt dial surround.
In that example the simpler and more straight
forward solution was taken by simply drilling a
hole in the decorative surround for key to turn
the adjustment arbor. One can also see that the
wheel planting with the plates was slightly
different as the main barrel winding arbor is
lower than the one in this example. This is a
good illustration of how by the end of the 18th
century clock making was a fully integrated
industry with specialized companies to make the
movement, orrery makers, casters making the gilt
surround and statuary, and dial makers for
variety of made-to-order clocks by different
makers to the end customer.

The view of the top of the orrery table after
finishing, first photo. I purposefully did not
polish out the shadows of the stopped wheels
that were etched into the surface from
contaminants falling from above. The prior page
has the before look. For oxidation to have made
such a picture the wheels must have been frozen
for a very long time, perhaps over a hundred
years or more. All parts are first put into an
ultrasonic cleaner using a water-based degreaser
to remove dirt and old lubricants then I use
Simichrome© as the
polishing medium and a soft terry cloth for
larger, less fragile parts, polishing by hand.
For smaller parts and areas, as illustrated in
the second photo, the thin rims and spokes of
the wheels are initially treated with a cotton
wheel charged with the same polishing compound.
I use the slowest speed available. Afterward the
entire part is carefully finished off by hand to
achieve a mirror polish. This two-step process
is used in this project because the oxidation is
quite extensive. Otherwise everything could have
been done by hand. Afterward any polish residue
is removed in the ultrasonic tank.
Polished orrery parts now ready for
reassembly. I took care not to polish the
concentric tube work, except the outside of the
outer tube. This was to lessen any material
removal and the fact that these areas cannot be
seen after reassembly, and results in the tubes
being as closely aligned within each other as
possible. A dry Teflon lubricant was used for
the concentric tubing, thus avoiding any oil
creep as well as contamination from dust or
pollution, particularly because of their
vertical orientation.

Two views of the orrery wheel work.

Another photos set. The Earth/Moon armature is
seen ready for mounting in the second photo.

A before and after shot of the orrery.

The first photo shows how the orrery armatures
that represent the planets of Mars Jupiter and
Saturn can be folded to allow the neck opening
of the glass celestial globe to be lowered past
the orrery. Next photo shows the re-installment
of the three Atlas statuary.

The clock and orrery are installed within the
statuary, orrery is still folded, in the next
photo the arms
are deployed.

The clock as received was missing its
pendulum. Given the photos of the clock from the
Worshipful Company of Clockmakers, the original
was probably a simple tapered cylinder that had
a smaller diameter at the top and a larger
diameter at the base. I had looked for one like
this or maybe even a pear-shaped type that was
also popular on verge bracket clocks at the
time. A reproduction silk one-half second thread
pendulum was available on the web. The correct
length is far shorter, so this had to be
fabricated. The rectangular metal shape that was
designed to meet the pendulum crutch was much
longer and wider than that which was permitted
by the original rectangular opening in the
extant crutch. That part was fabricated to
better fit what was called for in the original
design.

However, there was a problem. The clock ran
well with the temporary pendulum, the total
weight being .45 oz. The replacement pendulum
was over 1.2 oz and was too heavy for the clock
to drive. One option would be to make the
simple, small tapered cylinder, or alter what I
had on hand to reduce the weight. Again here I
have made a change as I did with the star to
hide the ugly punch marks around the pendulum
adjustment arbor and this too is completely
reversible. Much of the surrounding material
around the face was removed.

The final weight of the reworked pendulum
came in at .47 oz compared with the temporary
pendulum at .45 oz. and works well.

The revised pendulum in place, and in the
second photo the silk thread wrapped around the
adjustment arbor in its place, black arrow. The
yellow arrow shows the empty hole where that
arbor was originally placed. One can see where
the suspension mount has a 'V' cut into it to
accommodate where the arbor would exit the hole.
This is obviously where the original designed
called for it to be.

Collecting clocks can be fun!
