Dating a dueber watch
Chris' explanation isn't as detailed as Kent's, but it includes pictures which can be very helpful.Sometime in the next week or so, I will be moving my website from one ISP to another.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.
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.The Online Database for the Elgin Watch Company can tell you a great deal of information about your watch, based on just the serial number off the movement.(The "movement" is also sometimes called the "watch works".) Important!