Help with Musical Pocket Watch

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
Hello,

I have a musical pocket watch that came with a loose piece and the screw to attach it. I believe it is some kind of spring tensioner for the musical spring? Please could someone describe its function and how to properly reassemble it? I'm not sure why it was removed. The watch seems to be fully functional.

I also included the original key in the photo. It has an interesting 3D portrait designed into it. Has anyone seen this before? Does anyone know what this kind of 3D portrait is called?

Thank you,
Chris

1.JPG 2.JPG 3.JPG
 

gmorse

NAWCC Member
Jan 7, 2011
12,620
2,211
113
Breamore, Hampshire, UK
Country
Region
Hi Chris,

The 'spare part' you have is a piece of the stop-work for the mainspring barrel, and it fits in the lower hole to the left of the barrel arbor. You can see its shadow on the barrel. However, there should be another part which fits on the arbor square, consisting of a finger to engage with the slots on the piece you still have. Since its function is to limit the effective number of turns the spring can have, restricting it to the central, flatter portion of its power curve, its absence won't have a significant effect on the running of the watch. It's quite usual to find that all or part of these mechanisms have been removed by previous repairers, possibly because they didn't want the bother of setting them up properly.

DSCF8884 - Copy.JPG

This is how the complete parts engage, although it shows the stop-work mounted on the barrel lid rather than the body.

The image in the key looks like some sort of cameo, but its state suggests that it may be made of some softer substance, perhaps papier-mâché?

Most of these seem to have cylinder escapements like yours, probably to make a slimmer movement.

Regards,

Graham
 

agemo

Registered User
Apr 5, 2011
402
411
63
71
SAINT-NAZAIRE - FRANCE
Country
Region
Hi,
Many watches are found without their "croix de Malte" system because when they are dismantled, people do not know how to reassemble them.
There is a manipulation to do by counting the number of lathe of key, to replace the cross and the other piece.
I also think that on this key there is a cameo ivory or porcelain perhaps ?

Amicalement GG
 

gmorse

NAWCC Member
Jan 7, 2011
12,620
2,211
113
Breamore, Hampshire, UK
Country
Region
Hi Chris,
However, there should be another part which fits on the arbor square, consisting of a finger to engage with the slots on the piece you still have.
I think this piece may be still there on the barrel arbor square, but with the finger piece broken off. In the example I showed earlier that had happened to the finger. These pieces are normally left quite hard, so any heavyhandedness on the part of the owner can result in breakage.

Regards,

Graham
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
Thank you, it makes more sense to me now. This allows for the elimination of the fusee from the design. I was aware Lepine devised a method to only use the constant force region of the mainspring, but I didn't know how or by what mechanism. I assume this must be it? However, I have more questions. I would really appreciate it if you would share your knowledge:

1) How does it prevent usage of the early part of the mainspring? Is there a separate pre-tensioner to do this? Or does this "croix de Malte" piece prevent the usage of both the early and later portions of the mainspring power curve?

2) I understand that cylinder escapements are less susceptible to variations is mainspring force than verge. What about later watches with a detached lever? Do those need to use the more constant force portions of the power curve? If so, how is this done?

3) I took photos of the top of the barrel. I was a little worried because it appeared smooth on the side where the piece belongs. However, the finger is present on the other side. I looked at it under magnification and it does not appear to be broken or sheared in anyway. Please could you walk me through how to properly re-install the piece?

Thank you,
Chris

4.JPG 5.JPG 6.JPG
 

gmorse

NAWCC Member
Jan 7, 2011
12,620
2,211
113
Breamore, Hampshire, UK
Country
Region
Hi Chris,
How does it prevent usage of the early part of the mainspring? Is there a separate pre-tensioner to do this? Or does this "croix de Malte" piece prevent the usage of both the early and later portions of the mainspring power curve?
The mechanism does work at both ends of the cycle. When installing, the spring is wound for about one turn before fitting the Maltese cross piece in a position which prevents the arbor from turning back again. This means that the finger must jam against the rim of the cross beyond the slotted portion, as in this example. Here, the arbor cannot turn any further clockwise because the sector that's driven by the finger piece and hence trying to turn anticlockwise has no concave clearance, whereas all the others have. At the other end of the wind, the situation will be duplicated in the opposite direction.

I'm not sure that the screw with your Maltese cross is the right one for it. The right screw will have a shoulder under its head to prevent the screw bearing down on the wheel when it's fully tightened and jamming it; the wheel has to be able to turn freely to work properly.

DSCF8910.JPG DSCF8868.JPG

The second picture is a page from the J. Malcolm Wild book on wheel and pinion cutting, and clarifies the shapes and proportions of the two pieces. Although your slotted 'Maltese Cross' wheel doesn't have slots all the way round, it works in exactly the same way. Whereas this example will restrict the winding to four turns, yours appears to make that six.

I understand that cylinder escapements are less susceptible to variations is mainspring force than verge. What about later watches with a detached lever? Do those need to use the more constant force portions of the power curve? If so, how is this done?
Any escapement could be fitted with this type of stop-work. In the specific case of the cylinder, although it's also frictional rest, the effect of an increase in mainspring force results in more friction between the escape teeth and the cylinder and hence tends to compensate for this. The majority of Swiss cylinders still around today were fitted with Geneva stop-work, and most appear to have had it disabled.

Detached levers, if the escapement is truly isochronous, shouldn't theoretically need any device to compensate for variations in spring power over the duration of the wind, but in practice we know that they usually do. The fact that stop-work is very rarely fitted in current watches has more to do with improvements in mainspring design and metallurgy I believe.

Regards,

Graham
 
  • Love
Reactions: aucaj

Dr. Jon

Moderator
NAWCC Member
Dec 14, 2001
6,537
929
113
New Hampshire
Country
Region
The question of the need for constant force seemed to have been buried with the rise of detached escapements such as the lever and the detent. There was a lot of thepretical and practical work to make balances isochronous, meaning little variation in rate over the range of applied power.

Stop work controls that range of power with the nice bit that when set up properly a watch will start at the first "Click" on the winding ratchet.

Timing trials from the late 1800's to early 20th century showed that stop wprk equipped watches crushed fusee driven one.

Today there is a comeback on constant force in several forms all very expensive and so far none has made quantitative claims of accuracy improvement over very high grade simple levers.

Stop work is not fitted to modern automatic watches because they have slip clutches. When wound beyind a set tension the outside the mainspring slips inside the barrel.
 
  • Like
Reactions: aucaj

gmorse

NAWCC Member
Jan 7, 2011
12,620
2,211
113
Breamore, Hampshire, UK
Country
Region
Hi Jon,

There's a beautiful but regrettably short animation of the Mudge remontoir by the late John Redfern here. Coincidentally, one of the marine timekeepers in which this was used, (the Thomas Mudge 'Green'), will be in part 1 of the selling exhibition of Dr. John C. Taylor's amazing collection of clocks and watches by Carter Marsh in Winchester during July. The catalogue is available online and can be drooled over at leisure.

Regards,

Graham
 
  • Like
Reactions: roughbarked

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
Hi Chris,


The mechanism does work at both ends of the cycle. When installing, the spring is wound for about one turn before fitting the Maltese cross piece in a position which prevents the arbor from turning back again. This means that the finger must jam against the rim of the cross beyond the slotted portion, as in this example. Here, the arbor cannot turn any further clockwise because the sector that's driven by the finger piece and hence trying to turn anticlockwise has no concave clearance, whereas all the others have. At the other end of the wind, the situation will be duplicated in the opposite direction.

I'm not sure that the screw with your Maltese cross is the right one for it. The right screw will have a shoulder under its head to prevent the screw bearing down on the wheel when it's fully tightened and jamming it; the wheel has to be able to turn freely to work properly.

View attachment 657313 View attachment 657314

The second picture is a page from the J. Malcolm Wild book on wheel and pinion cutting, and clarifies the shapes and proportions of the two pieces. Although your slotted 'Maltese Cross' wheel doesn't have slots all the way round, it works in exactly the same way. Whereas this example will restrict the winding to four turns, yours appears to make that six.



Any escapement could be fitted with this type of stop-work. In the specific case of the cylinder, although it's also frictional rest, the effect of an increase in mainspring force results in more friction between the escape teeth and the cylinder and hence tends to compensate for this. The majority of Swiss cylinders still around today were fitted with Geneva stop-work, and most appear to have had it disabled.

Detached levers, if the escapement is truly isochronous, shouldn't theoretically need any device to compensate for variations in spring power over the duration of the wind, but in practice we know that they usually do. The fact that stop-work is very rarely fitted in current watches has more to do with improvements in mainspring design and metallurgy I believe.

Regards,

Graham
Hi Graham,

The screw has a shoulder on it, but is not tightening. It appears that the screw threads on the screw have been stripped. The threaded hole looks okay. I will have to replace the screw.

Thank you for you help.

Chris
 

gmorse

NAWCC Member
Jan 7, 2011
12,620
2,211
113
Breamore, Hampshire, UK
Country
Region
Hi Chris,
I will have to replace the screw.
The thread is most unlikely to be any of the modern standards, but it could be one of the Martin Fils 'Latard' or Delamure 'Bourgeaux' screw plates, which are still obtainable occasionally.

Regards,

Graham
 
  • Like
Reactions: aucaj

Philip Poniz

Moderator
NAWCC Fellow
NAWCC Member
Feb 22, 2012
279
258
63
Princeton, NJ
I have a musical pocket watch that came with a loose piece and the screw to attach it.
This forum welcomes all complicated watches, including the ones with repair questions. However, strictly repair questions should be directed to the Watch Repair forum. Could you send us under the dial photo that we know exactly what type of musical watch we are having here? Especially, if there are any marks.
Thank you
 
  • Like
Reactions: aucaj

tick talk

Registered User
Sep 16, 2008
636
123
43
Country
I've heard an apocryphal story that when V&C first introduced a Geneva stop-works into their movements, some customers were unhappy with the shortened running time and returned them to have it removed. Does this sound plausible?
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
I've heard an apocryphal story that when V&C first introduced a Geneva stop-works into their movements, some customers were unhappy with the shortened running time and returned them to have it removed. Does this sound plausible?
In this particular case, I don't think so. The "croix de Malte" with the loose piece is on the musical barrel. It helps to ensure the music does not play at a different rate at various points in the wind.
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
This forum welcomes all complicated watches, including the ones with repair questions. However, strictly repair questions should be directed to the Watch Repair forum. Could you send us under the dial photo that we know exactly what type of musical watch we are having here? Especially, if there are any marks.
Thank you

Hello Philip,

I don't wish to remove the dial at this time, but I have attached additional photos of my three musical pieces. Please, is there anything further you can tell me from these photos?

Regards,
Chris

1.JPG 2.JPG
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
The first watch is marked Jaquet Droz on the dial and has a hallmark like the attached photo. Can anyone tell me more about this maker?

hallmark.jpg
 

Philip Poniz

Moderator
NAWCC Fellow
NAWCC Member
Feb 22, 2012
279
258
63
Princeton, NJ
The first watch is marked Jaquet Droz on the dial and has a hallmark like the attached photo. Can anyone tell me more about this maker?
Gladly, but please provide photos of the movement, front and back, and the markings inside the back cover. Without them, at first glance, the watch appears from after Droz and his partner Lechot died
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
I have removed the dial and found some markings on the plate. I have attached a new set of photos that include several views. I am not sure the case is original or even the dial. There are two slides on the case at '2' and '10'. I would expect one to lock the repeater plunger in place and the other to press against the gongs? They do not seem to do anything. Please could you help to understand more about this watch and its maker?

Thank you,
Chris

1.JPG 2.JPG 3.JPG 4.JPG 5.JPG 6.JPG 7.JPG 8.JPG
 
  • Like
Reactions: Brunod

Philip Poniz

Moderator
NAWCC Fellow
NAWCC Member
Feb 22, 2012
279
258
63
Princeton, NJ
That helps a lot, but the most important mark is the one just after the serial number inside the back cover, the lozenge one.
 

agemo

Registered User
Apr 5, 2011
402
411
63
71
SAINT-NAZAIRE - FRANCE
Country
Region
The first watch is marked Jaquet Droz on the dial and has a hallmark like the attached photo. Can anyone tell me more about this maker?
Hi,
This is the hallmark for French silver second title (800 thousandths) established in 1838.

Amicalement GG
 

gmorse

NAWCC Member
Jan 7, 2011
12,620
2,211
113
Breamore, Hampshire, UK
Country
Region
Hi Chris,
There are two slides on the case at '2' and '10'. I would expect one to lock the repeater plunger in place and the other to press against the gongs? They do not seem to do anything.
There is sometimes a slide which allows the music to be played at will, independently of the repeater.

Regards,

Graham
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
Hi Chris,


There is sometimes a slide which allows the music to be played at will, independently of the repeater.

Regards,

Graham
I will try to get a better look at the slides and where they would be engaging. On the other two, there is a release lever to allow the music to play on demand. The Droz does not seem to have that same lever...
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
That helps a lot, but the most important mark is the one just after the serial number inside the back cover, the lozenge one.
I have attached magnified photos of the markings. I also took a closer look at the slides on the sides of the case. They do not appear to engage anything on the movement or the gongs. I suspect this case is a replacement.

1.JPG 2.JPG 3.JPG 4.JPG
 

Philip Poniz

Moderator
NAWCC Fellow
NAWCC Member
Feb 22, 2012
279
258
63
Princeton, NJ
Thank you for the mark's photos. Unfortunately, they are not sharp enough to determine the details. The lozenge mark, which is the casemaker's mark, seems to have a vertical post, maybe a key, flanked by two letters. What post and what letters? The Minerva's head details determine if the case was made in Paris or outside.
I am reasonably sure the case is original to the movement; the cuvette's winding/setting apertures' perfect alignment with the posts indicates that. Therefore, the marks' details are essential to analyze the watch.
 

aucaj

Registered User
Feb 2, 2021
225
149
43
41
Country
Ok, I think this is better. I cleaned the area and took another set of magnified photos.

The movement appears to be held in place by a screw going through the bottom of the case (see photo). There is also a cutaway in the side but I'm not sure what it is for.

1.JPG 2.JPG 3.JPG 4.JPG 5.JPG 6.JPG 7.JPG 8.JPG
 

Philip Poniz

Moderator
NAWCC Fellow
NAWCC Member
Feb 22, 2012
279
258
63
Princeton, NJ
I understand having doubts about the originality of the case by the screws attaching the case to the movement from the outside, but looking at the perfect alignment of the cuvette’s apertures with the winding posts, one must assume that it was a repairman, who had a problem securing the movement and helped himself in this way. It is not the first time I have seen such a solution. Those watch cases are not very rigid. Sometimes one might have a problem with securing the movement correctly, especially if one is not experienced. In my mind, the case is original.

The lozenge mark was recorded by Pierre-Joseph Léger, a Parisian casemaker, who registered this mark, a burning torch flanked by letters J and L, in 1853 (see below).

Leger 1853 Monteur de Boites, Paris.jpg
Therefore, the case is from the 1850s. It does not look like it, but that is what it is. I know an identical watch (below), also in a silver case, hallmarked London 1856! Apparently, those musical repeaters were still popular in the 1850s.

Music Rep on back, silver London HM 1856.png

The ebauche must have been launched around 1812 and been produced for years with small variations. There exists one, in gold, with an 1814 inscription (below).

Music Rep on Back, Inscr 1814.png

Assuming that the dial is original to the movement, the signature on the dial is a fake. Pierre-Jaquet-Droz, one of the most famous mechanical automata and musical pieces makers, died in 1790, his son, Henry-Louis, a year later, and their partner, and also adopted son, Jean Frédéric Leschot, in 1827.

There are other indications that the watch cannot be Droz's. Among a few dozen Jaquet-Droz watches, singing bird boxes, etc., that I handled, I do not remember seeing a single one cased in silver. The engraving is far from the quality Jaquet-Droz is known to produce. It looks provincial, not Parisian. It is possible that Léger just put the case together from parts made in Switzerland or in the French province. He was registered as a case fitter (monteur de boites).

Music Rep on Back LKO.jpg
A watch based on the same ebauche.

The watch teaches us how late those Meylan’s musical watches were made and sold. Philippe Maylan invented the disc-type (sur plateau) musical mechanism around 1810, and his company, Piguet et Meylan, produced many of them during its existence between 1811 and 1828. Soon, those movements were also produced by others. Judging by the layouts, there were at least three other manufacturers and on occasion one finds an odd unique piece, such as the famous musical watches made by Louis Audemars.

If you look in horological literature, including auction catalogs, you will find that the vast majority of sur plateau watches are dated “circa 1820”. One gets an impression that there was an outburst of musical watches around 1820 and then the production stopped for the rest of the century. In fact, as we learn from this watch, they were sold way into the 19th century. I know of one such gold watch, hallmarked in the late 1850s, which an auction house described as “with a later made case”, which was definitely original. They could not believe that such a watch could have been made/sold so late. Those musical watches, regardless of the fact that stylistically they were old, were still in demand 30-40 years after their invention. A similar situation existed with British watches for the Ottoman market. 18th century-style watches were sold there way into the 19th century. Turks liked to wear watches their fathers and grandfathers wore. They are often wrongly referred to as the 18th century ones with later cases.

In the sur plateau musical arrangement, the vibrating blades are laid out at a circle’s segment at equal intervals and move progressively inward toward the center of the disc. The stiffer blades, playing the higher notes, are acted upon by the pins near the center of the disc.

The lower notes are played by longer blades engaging pins set closer to the periphery of the disc. This arrangement equalizes the resistance of the blades and assures a constant tempo. The number of the blades varies between 16 and 27, and usually, several notes are duplicated.

Piguet et Meylan’s early mechanisms had pins and blades only on one side of the disc, but soon they were placed on both sides, which allowed them to increase the number of the blades. In your watch, the shortest blade appears to be missing or has never been installed.

The question remains when and where the 1850s movements came from? The few musical watches known to be sold in 1850s all are based on the same ebauche. Were they produced in the 1850? Were they finished from a bunch of ebauches? Where were they finished?

Philip Poniz
 

Forum statistics

Threads
167,008
Messages
1,455,385
Members
87,242
Latest member
UltraTitan
Encyclopedia Pages
1,057
Total wiki contributions
2,914
Last edit
E. Howard & Co. by Clint Geller