My first love, when it comes to Hamilton watches, was pocket watches. Like most collectors, my first introduction to vintage watches was by inheriting some pieces from my grandfather. Some were my great grandfather's, in fact. All of them were pocket watches and the best of which was a Hamilton 992B railroad watch. My grandfather worked for a railroad for a while, as well as a prison guard and a shopkeeper. Watches make great heirlooms and I think of my grandfather's life every time I wind his watch.
I recently was contacted by someone who's prized Hamilton pocket watch was damaged when one of his kids played with it a little too roughly. It's over 110 years old and is a lever set 974 pocket watch from 1911.
The 974 is an entry level 16 size model at it was made for 20+ years. It evolved over time and although the main elements stayed the same, there are some important elements that varied. One variable is the 974 came in lever set as well as negative set variants. Level set was important because the watch couldn't accidentally pop into the time setting position the way a negative set movement can. I'll point out some of the other unique features below.
As received, the watch appears to be in excellent shape overall. It shows some wear over the last 110 yeas but it's definitely not worn out.
The back cover is nicely engrave with a bird and floral design.
The movement is complete and with a slight shake I was able to get it to tick - that's a good sign. Notice the crown wheel is held down with two screws. On later versions a single reverse thread screw would be used. A reverse thread screw is opposite a normal screw so instead of "lefty loosey" it's "righty loosey" and you turn it the opposite direction to remove it (or you break it by over-tightening). The two screw design is more easily removed.
I don't normally check the timing of watches before I work on them but in this case I wanted to see what I was in for. I gave the watch a few winds, got it running, and put it on the timer to see what it looked like. It's running slow but that because I didn't wind it very much. The beat error of 9.4 ms means the balance is out of alignment, that could have happened when it got banged by the owner's kids. In fact, it may have gotten "over-banked", where the balance impulse jewel gets on the wrong side of the pallet fork and stops the watch.
Here's another unique feature of an early Hamilton pocket watch. The dial has four dial feet... in a few years that would change to three feet so replacing dials on old pocket watches requires you to know how many feet are involved. Getting a dial from a later 974 wouldn't work for this watch.
A lever set movement has a lever that you slide out (at the 1:00 position) to move the keyless works into the time setting position. A negative set movement would have a couple extra springs under the dial and require a different case design as well. I like lever set movements, they are less troublesome.
I noticed some little gold flecks under the dial and after looking closely I can see the minute wheel is missing a bunch of teeth on the inner pinion.
I also saw the hour wheel (that engages the minute wheel) is missing a tooth or two. I found a few more tooth pieces as I went along. This would definitely stop a watch or cause the minute hand to move while the hour hand didn't.
I was happy to see a white alloy mainspring is already installed. That's one less thing for me to deal with.
I have to look closely at the balance wheel from this angle to try to identify which side the balance is off by. The photo didn't capture it but I could see the impulse jewel was off to the right. I can adjust that later.
With the balance removed you can see the blue hairspring stud is just above the arm on the left, I'll rotate the hairspring counter clockwise a smidgeon to adjust the position of the impulse jewel relative to the hairspring stud. Confused yet? It takes a while to grasp the concept but in a nutshell the only two parts of the balance that are fixed in position are the hairspring stud (attached the balance cock) and the impulse jewel that engages the pallet fork. The position of the stud relative to the impulse jewel determines how centered the impulse jewel is.
I'll pull a "new" minute wheel and hour wheel from a donor movement and clean them with the other parts.
Everything is cleaned and dried before being reassembled. Pocket watches have about the same number of parts as wrist watches but they are much bigger and take up a lot of room when they are laid out.
The movement is reassembled and I gave the balance my best guess in terms of adjustment. I'll have to install it to see how I did.
Well, the beat error is reduced to 3.5 ms but that's still a bit too high so I will give it another go. I'd like to get it under 1.0 if I can.
There... that's much better. 0.7ms is good enough. 0.0 would be ideal but you're talking about a very small adjustment and every attempt risks goofing up the balance. I've learned the hard way that good is usually good enough.
The replacement minute wheel and hour wheel are in place and look just as they should. Cannon pinion holds the minute hand and the cannon pinion turns the minute wheel which turns the hour wheel that holds the hour hand. These two parts are what keep the two hands synchronized.
The reassembled movement is installed back in the case and is ready to go home to its owner. Hopefully it will be safely hidden from little fingers but still enjoyed as a treasured timekeeper until it can be passed down to the next generation.
Thats a great watch! Great job on the restoration.ReplyDelete