Each of the twenty-four Seth Thomas pocket watch models represents an underlying foundational standard to which all of its mechanisms conform, from the most basic non-adjusted 7 jewel version of that model to the most advanced, adjusted to six positions, 23 jewel version.  Some components of the foundational standard would include the type of top plate utilized for the mechanism, be it a full plate, a 3/4 plate, a divided 3/4 plate, or a bridge plate, and the orientation of the mechanism, hunting case, open-face, or an adaptable orientation. Serial number ranges are also a useful tool in establishing the identity of a movement.  The 1904 Seth Thomas Watch Material Catalog No. 650 contains a partial list of movement serial numbers that shows the model numbers associated with the production blocks. That list and reference to the Pocket Watch Database are the sources of serial number information provided on the Seth Thomas Fan Space.  There is little agreement between sources of information related the production dates of Seth Thomas pocket watches.  The charts published by Ehrhardt & Meggers in American Pocket Watches – Identification and Price Guide Beginning to End 1830-1999; Gilbert, Engle & Shugart in Complete Price Guide to Watches – 2012; and the information set presented within the Pocket Watch Database are each quite different.  By consulting each of these resources and factoring in historical references from researching private label pocket watches and information gained through observation of advertisements in catalogs and magazines, approximate production date ranges are estimated and presented on the Seth Thomas Fan Space for each model.

The three areas of this section will fill in the details of the underlying foundational standards associated with each Seth Thomas pocket watch model, and describe some of the variables within that standard that may go into making up the grade of each mechanism within that model.  Photographic illustrations of specimens from each model are provided so that the components can be seen, not just imagined in some abstract way or by means of a two-dimensional drawing. The photographic illustrations include mechanisms in various stages of disassembly. Some are not for the faint of heart, and parental guidance is advised in viewing the Model 14 photo album as there are photographs, and mention made, of male and female parts.