[Steve66]

Just throwing it out here but could I slow the watch down via the mentioned tompion disc and if yes, in which direction?
Thank you

 

[nevenbekriev]

For sure this kind of watches can be regulated to work in limits of +/- 3 min/day. But, this is when they work on the table top face up only. In pocket they will perform worse and yes, 15 min is good result. But, to work correctly, the watch must have very small radial free play in balance and crown wheel bearings and the balance to be well (dynamic) poised. Isochronism is another serious problem here - the spring torque has to be correctly equalized by the fusee. No one can tell what the condition of the OP's watch is only by the pictures here.
OP, try to turn the square shaft on the silver dial with small numbers counter clockwise. If the regulator can move more in this direction, it will slow the watch. Another possible reason that may be for the watch to work faster is 'shallow' escapement engagement.

 

[Fergie307]

This is what you will typically have underneath. In the circle you can see two small pins below the moving plate. The hairspring fits between these. When you turn the regulator the rack moves, changing the effective length of the spring as the pins slide along it.
I would be very careful and only adjust it a tiny amount initially and see what effect it has. The reason I say that is because if it hasn't been serviced and checked the spring can become stuck to the pins, rather than sliding between them. If this is the case moving it could damage the spring as it can bunch up behind the pins rather than sliding through them. If this happens it will actually run even faster. Another possibility is that the spring is not correctly installed, so it is not actually between the pins at all, but inside them. This would also make it run fast. In this case the regulator will have little or no effect.
If moving the adjuster a small amount does slow it then try a bit more, but I think an error of a minute an hour is not going to be fixed by the regulator, I'm afraid there is something more to it.

 

[Steve66]

You guys have been brilliant and I am very grateful.
Thank you for sharing your knowledge.
Digesting these posts, I am out of my league here so I will have the watch professionally serviced when funds permit.
In the meantime, it is a beautiful timepiece and I am going to be the custodian of it for the next generation.

 

[Fergie307]

Not sure how much you know about the actual set up of these. You might find this interesting.
The animation in the link relates to a clock, but shows the way it operates.
Then you have the whole train associated with the escapement.
And an image of the sort of wear you can find on the flags, which leads to the shallow engagement @nevenbekriev was referring to. If it is really bad then the only answer is to make a new one, easy peasy .... Not!

The Verge Escapement – Redfern Animation

The verge escapement was developed in the 13th century and made mechanical clocks possible. It consists of two pallets set at approximately right angles to each other which alternately stop and release the escape wheel, one tooth at a time, allowing it to rotate in a regular and controlled...

redfernanimation.com

 

[spinynorman]

Yesterday I set all my pocket watches running for the WRUW oldies thread. Early this morning I took another picture which shows how they’ve kept time over 20 hours.

The two on the right are lever movements, never been serviced to my knowledge and both still show the right time, near enough. The other four are fusee movements from the 1870s-90s. All have been professionally serviced/restored. As you can see, they’re all slow.

 

[Fergie307]

Fusees are one instance where I would always try and retain the original spring, although of course on a watch that old it is unlikely to be "the original".
Really problematic trying to get a new spring to match the fusee. Often a case of trying different ones until you find something close, very time consuming.

 

[Fergie307]

I have been nerdy enough to use a loupe to see exactly when the minute hand meets the mark on the ring, then plot the results against a radio quartz clock. Do it every 20 minutes and you get an idea of what is going on.
Will give you an idea if it might be related to a mismatch between fusee and spring, or simply needs regulation or maybe the hairspring re pinning a tad shorter.
A mismatch will typically result in the graph going up and down, sometimes by a lot at the beginning and end particularly.
Bit like a time graph though, don't do it with something that runs well and keeps good time, you will just find things to worry about that you didn't even know were there🙂

 

[Fergie307]

Prompted by this thread I dug mine out. It is a Charles Stone of Liverpool, hallmarked Birmingham 1803. Silver paired case by William Hutton of Sheffield.
The movement itself is in nice condition apart from the dial which is badly damaged. I have quite a collection of period dials including several convex ones of the correct size and similar date, so that can be replaced.
It also needs some work on the case. The outer has a few dents and the pendant is badly damaged. I have a small collection of silver spoons, bought for pennies at car boots which I use as a source of silver for repairs. One of these will in due course donate the silver to make a new pendant.
For these reasons it has remained in my to do box since buying it some time ago.
The movement is very clean, so clearly has had some attention. I was drawn to it because I rather like the face in the engraving. It also has a rather unusual regulator. It has a plain blued disc in lieu of the normal numbered Tompion dial, but the rack also incorporates a pointer. It looked pretty "honest" to me, not having been messed about with.
When I gave it a run briefly upon buying it my triage notes show it gained 11 minutes in 24 hours, and the regulator was reluctant to turn.
Anyway, having done a little tinkering and got the regulator freed up and working smoothly, in the last 24 hours it has gained 3m 30s, so quite chuffed with that. There is a little more side shake in the staff than I would like, so once I can give it a full going over I dare say that may improve a bit more.
This was dial up. So far been running for about 4 hours dial down and looks as though it will be very similar. I expect it to lose a little pendant up, but we shall see.

 

[Fergie307]

So having left it running dial down overnight this is the situation this morning. I think it is definitely a good un 🙂
After 4 hours or so it had gained a little so I was expecting a similar result to dial up.