Over time the standard evolved to dictate a minimum number of jewels and the use of a "micro-regulator" - a spring loaded device that allows the regulator on the balance to be secured and set to a fine degree with a screw driver. Watches also had to be regularly serviced and certified to keep time appropriately.
I started out collecting pocket watches but moved on to wrist watches, as I could enjoy them a lot more by wearing them every day. But I still have a soft spot for a nice pocket watch (or even not-so-nice ones too).
I recently picked up one of Hamilton's finest railroad watches - a 21 jewel, 16 size 992B. Based on the 1948 catalogs I would identify it as a Model No. 11, with a single sunk HG (heavy gothic) dial. It's the case on the left with the dial on the right in the catalog snip below.
I got it for a good price as it had a broken mainspring and wouldn't run. It was also very dirty, but the case was in great shape.
The 992B was introduced in the late 1930's and replaced the 992 movement which was used for the prior decades. There's also a 992E - which was created in 1934 when the Elinvar hairspring was introduced. The 992B continued to be made through the 1960's. I can tell by the serial number that this watch was made in 1948.
Pocket watches are fun challenges to work on. They're bigger so that's actually a nice change from the tiny parts in wrist watches but the setting mechanism and some of the other pocket watch-specific parts can be unfamiliar and a little puzzling.
As with all overhauls, the first thing to do is to get the movement out of the case. In the shot below the front bezel has been removed. The 992B is a "lever set" watch - so you pull out a lever to set the time. This is different than a "pendant set" watch where you pull the crown and stem to set the time. You can see below that I pulled the level out (near the 1) to show you this is now in "time setting" mode"
Flipping the watch over, you can see the 992B is a nice looking movement with attractive damascening. Two case screws hold the movement in the center case. You can see them on opposing sides of the movement circumference. Once they're removed the movement will come out the front of the case.
Here's the movement safely secured in the movement holder. Since the mainspring is broken there is no need to release any remaining tension in the barrel. If it was not broken this would be the time to make sure there was no stored energy in the watch - as these mainsprings can pack a wallop.
Three dial foot screws hold the dial on. With the dial and hands removed you can see this looks a lot like a giant wrist watch movement. The main difference is the "keyless works" used to wind the watch and set the time. The set lever has been removed in the shot below... you'll see it again later.
First off is the hour wheel and cannon pinion.
Here the parts of the keyless works have been removed. There's a very strong spring in there that surprised me when it shot out of the movement. Fortunately I was able to find it after a few minutes of panicked searching.
The cap jewels on the left side will come off next. You can see the escape wheel's cap jewel is held with two screws and the pallet fork and balance wheel's cap jewels are held with three screws.
Flipping back to the reverse of the movement, the Ratchet wheel and screw can be removed, then the three screws for the "barrel bridge" are removed so the bridge can be taken off.
With the barrel bridge gone you can see the mainspring barrel, center wheel and third wheel are now exposed.
Two screws hold the "train bridge" on and with that removed the fourth wheel and escape wheel are now exposed. That leaves the one screw for the balance bridge and then the balance can come off too.
The only thing left on the back is the pallet fork and it's held in place with it's bridge. Two screws hold it on. You can see there is a lot of oil near the serial number... I see this a lot but I'm not really sure what it's from. I can get pretty gummy.
Here's a close up of the pallet fork. It's sometimes called an "anchor, for obvious reasons. There are two jewels called "pallet stones" on the ends. The engage the escape wheel and generate the tick tick tick noise you hear.
Opening up the mainspring barrel, you can see that this spring is broken (it's at about 11:00)
I'll install this new white-alloy mainspring once the barrel is cleaned up. Fortunately this spring came in the a holder that keeps it wound tight. I'll get one chance to install it right, otherwise I'll have to wind it again using my mainspring winder. I've done these by hand before too - it' s very challenging as these springs are super strong.
Here's the mainspring next to the empty barrel.
The barrel has a little slot for the "T-end" of the spring. This catches the spring on one end and the other end is caught by the arbor in the center - that allows the watch to wind and store energy. If either end slips the energy would be lost.
In this shot the spring is installed and the T-end is in it's slot.
Here, I've got the arbor installed... that can be tricky too. I'll apply a little mainspring grease to the spring before I close it up with it's cover.
Everything is now cleaned and drying. It's time for a little assembly. It goes back together in the reverse order that it came apart - except I'll put the balance assembly on last. You can see the little spring I lost in the top center of the parts... looks like a fish hook.
Everything goes back onto the front... the cap jewels and the keyless works. You can see the set lever has also been reinstalled. Now you can see how it works... you slide it out and it will push the lever that will move the watch into the time-setting mode (right now it's in winding mode).
Next, the pallet fork in reinstalled.
The escape wheel and the fourth wheel (that the second hand is attached to) go in next and are held in place with the train bridge.
Now the barrel, third wheel and center wheel go back in and are covered by the barrel bridge.
Last on is the balance assembly - and with a little mainspring tension this watch is brought back to life.
Running 5 seconds fast per day... not too shabby!
The cannon pinion and hour wheel go back on and this watch is ready for it's dial and hands.
And here it is, all polished up and looking like a new watch!
This watch is a real "thing of beauty".