Dating a dueber watch
The example below uses information from the American Waltham Watch Company, but that is just an example.You should consult the serial number table for the specific brand of watch movement you are trying to date by selecting a company from the menu on the left.Let's say you have a Waltham watch with serial number 21,607,210 as shown in the photo below.Note that we're using the serial number from the watch movement, not from the watch case.
By 1910, word of Elgin’s obsession with precision had spread around the world.
Looking at the table of Waltham serial numbers (see example below), you can see that number 20,900,000 was made in 1917 and 21,800,000 was made in 1918 (marked in red in the table below). Your movement serial number may not be in exactly the same location as the one in the photo, but you are looking for the serial number that is on the watch mechanism itself... This is an example using the Waltham serial number table.
Since your serial number falls between those two numbers, you know that your watch was made in 1917 or 1918. Cases and watches were often made by different companies and each usually has its own serial number. Be sure to use the table that is specific to YOUR brand of watch when looking up your serial number.
Hampden pocket watches, produced between 18, are still highly sought after as collectibles and daily carriers.
Hampden was credited with the first 23 jewel 16 size watch made in America.
In theory, this should all be transparent to everyone and there should be zero downtime.