Dating a wittnauer watch
Watches were produced using the "etablissage" method, where individual tradesman working out of small studios or their homes would produce parts (or sub-assemblies) which were then assembled and sold under the auspices of a single brand.
In 1832, Auguste Agassiz began selling etablissage-produced watches under the name "Agassiz & Compagnie" and was particularly successful selling those watches in North America.
This is probably the most common question watch collectors have.
Sometimes it is easy to answer, and sometimes it is impossible.
Some companies (as with the Gruen Watch Company), even lost rocords to fire or other natural disaster. I am sure they had no idea that their timepieces would someday be collected.
This will give a good idea of the manufacture date.
It will NOT tell you the actual date the watch was acquired...
many watches spent years in warehouses before being sold... If there are some letters incoroporated in the serial number (common with Hamilton and Elgin) your watch was probably made AFTER the last date on the chart.
These numbers are stamped on the back (outside) of the case. The code was usually stamped on the back of the watch case.
If there is no two symbols, it could be that your watch was made before 1948. For exabple, If you have a Bulova watch with the stamp M3 then it was made in 1963.