Horological Meandering

I've Got Your Back, Part 3

This is Part 3 of my series on casebacks, and in it I promised to reveal the secrets hidden inside your watch. Or perhaps I should say I am willing and able to show you the inside of some casebacks.

Writing in the watch on its back can be provided by the factory, as shown on the left inside a Longines-Wittnauer watch, or on the right inside a very old English pocket watch. This tradition did not start with wristwatches!

Nor did the tradition of watchmakers scribbling notes inside, as you can see in the Longines-Wittnauer. They usually indicated their identity and date of service.

Here's a one-piece Wyler case, where the movement comes out the front. You can see the information that's usually on the back of the watch has been provided here: Name of manufacture, location, model and serial number. The same appears on the outside with the addition of the model name "Lifeguard".

This elderly Rolex was inherited by a friend, and he wanted to know what was inside. Here's what I found on the inside of the snap-on caseback. There's definitely corrosion along the joint, even though it is "INOXYDABLE" or uncorrodable steel - i.e. stainless. There's a Rolex stamp, logo and model number.

Deciphering Rolex data is a world in itself and I am not an expert. YOU CAN READ MORE HERE

Here is the inside of a caseback on a friend's Patek and my own. Both are over 30 years old, and were serviced regularly. You can see the notations made by a series of watchmakers who were inside here. At first scratching in the case was the protocol, then later using a fine-tip permanent marker became common. In addition to the spontaneous writings, there are hallmarks, number, brand, country of origin, etc.

Here's one guy's explanation of his code:

"The AWCI gives you a lifetime code for personal identification Mine is 10^RD. When I mark a watch it's 10^RD then a date like 7/28/16 then under that coa t/c/cry/ax/2g which translates to tube and crown, crystal, axle, and 2 gaskets. I fit this into an area under 1/4/ inch square so you have to use a 10 power scope to read it. Rick"

Everyone made up their own code.

If there are serial numbers on both case and movement, they should match. You can see the number on the movement ring matches the caseback.

Ideally the watch and the caseback should be clean and tidy, like this Rolex.

and this Grand Seiko

Once in awhile you will come across this kind of inner, second cover.

This indicates the watch is magnetically shielded. The Rolex Milgauss, an Omega Aqua Terra, several Grand Seikos and a few other models are shielded watches which are not affected by -- how can I say it? -- a magnetic flux capacitor. You need this kind of watch in case you are driving the Back to the Future DeLorean-mobile. Or working at a power generating station.

Wikipedia says "The gauss, abbreviated as G or Gs, is the cgs unit of measurement of magnetic flux density (or "magnetic induction"). It is named after German mathematician and physicist Carl Friedrich Gauss. One gauss is defined as one maxwell per square centimeter. The cgs system has been superseded by the International System of Units (SI), which uses the tesla (unit T) as the unit of magnetic flux density. One gauss equals 1×10−4 tesla (100 μT), so 1 tesla=10000 gauss."

Yawn.

Thanks for stopping by. Please read Part 4 which is much more exciting!

Cazalea

I've Got Your Back, Part 3

I've Got Your Back, Part 3

No yawn there. Very interesting. Thank you

The part rarely seen...