Production Year
Approximate date the movement of a watch is produced. Factory records differ from year-to-year and factory-to-factory. Some records are more complete than others. For this reason, many factory production dates are approximate.

Size
System developed and agreed-upon by American watch manufacturers to determine the diameter of a watch movement. The larger the number, the larger the diameter of the movement. The numbers used for American watch movement sizing have no correlation to the actual measurement of the piece.

Jewels
Only jewels have a surface hard and perfect enough to allow metal parts to turn unceasingly year after year with a minimum of wear and friction. Jewels also hold the microscopic droplets of oil that lubricate each tiny pivot point. Raw jewels alone cost little; it’s their incredibly precise finish and their perfect positioning in the watch that give them value and make your watch run so dependably. While a certain number of jewels are necessary at vital points, an increase beyond this number does not always mean an increase in watch quality.

Grade
The grade of a movement is the identification of the level of quality to which it is finished, generally reflecting the amount of labor that went into them. There is some relationship to the cost of materials, but the greater cost was the labor to finish and adjust the parts to the precision necessary for good timekeeping and, to a lesser extent, the pleasing appearance of the movement. For cases, the value of the material was a much greater proportion, with some extra labor going into engraved designs.

Grading can be increased/decreased by adding jewels, damascening or adding levels of adjustment.

Model
Much like the model of a car, the model of a watch movement indicates the style of the piece and the level of labor and jeweling that went into the movement. Model names and numbers are used to determine railroad eligibility use and level of construction. Models names can be words or numbers.

Class
An internal notation used by a watch factory to note the level of production and type of a watch movement. This category can be used to note subtle differences between models and grades.

Run Quantity
Because special tooling and manufacturing techniques are required for each model and grade of movement, mechanisms are produced in groups called “runs.” A run can consist of a hundred or less up to tens of thousands per group. The total run quantity of a model or grade is the complete number assembled before the factory ceased production of that model.

Movement Configuration
The movement configuration of a watch identifies whether it was manufactured to go in a hunting case – a watch case with a cover that opens when the crown is pushed; or, whether it is designed for use in an open-face case, which has no
cover.

Movement Setting
The setting of a watch movement notes how the hands of the watch are moved to align with the correct time. Early watches hands were “set” by using a key to turn them; later, watches were set by pulling out the crown; turning it until the hands gestured to the proper time, then pushing in the crown. For railroad use, a watch should be “lever set”: A hidden lever located in a small slot near the edge of the dial must be pulled out before the hands can be adjusted. This safeguard was developed to protect watches from having their hands jostled out of time accidentally.

Movement Finish
The movement finish of a watch traditionally refers to its appearance: color, metal or decoration. A “gilt” finish is, in effect, gold-plated. A “nickel” finish means the solid nickel plates of the watch are polished. A “nickel damascened” finish means the nickel plates are brushed or decorated by hand or machine, thereby increasing the grade and value of the movement.

Plate
A watch movement is constructed so that wheels are held between “bridges” or “plates.” Some movements are full-plate, meaning they are two plates of metal with gears between them. Other movements may be “three quarter” plate, meaning there plates sandwiching the gears have an open space or gap in them. A “bridge” movement is a mechanism with thin fingers or “bridges” holding one end of the pivot, exposing most of the internal workings of the movement to be
seen.

Barrel
The barrel of a movement is the area containing its mainspring.plain barrel: i.e. without teeth, used in fusee watches and clocks. A chain, or cord, was wound around the plain barrel, connecting it to the fusee.

Going barrel is the form used in modern watches, is wound by turning the arbor and drives the watch movement by a ring of teeth around the barrel. This enables the mainspring to continue running the watch while it is being wound. Invented by Jean-Antoine Lépine.

A “hanging barrel” is a version of the going barrel that is supported by the
movement only at its upper end – a space-saving design.

A “motor” or “safety barrel” is used in pocket watches around 1900, a reverse variant of the going barrel in which the spring is wound by turning the barrel, and turns the watch movement by the central arbor. The purpose of this arrangement was that if the spring breaks, destructive recoil forces would not be applied to the vulnerable gear train.

Adjusted
An “adjusted” movement is one that is finished or specially “tuned” at the factory for certain applications. There are eight possible adjustments:
• Dial up
• Dial down
• Pendant up
• Pendant down
• Pendant left
• Pendant right
• Temperature (from 34–100 degrees Fahrenheit)
• Isochronism (the ability of the watch to keep time, regardless of the mainspring’s level of tension).

Positional adjustments are attained by careful poising (ensuring even weight distribution) of the balance-hairspring system as well as careful control of the shape and polish on the balance pivots. All of this achieves an equalization of the effect of gravity on the watch in various positions. Positional adjustments are achieved through careful adjustment of each of these factors, provided by repeated trials on a timing machine. Thus, adjusting a watch to position requires many hours of labor, increasing the cost of the watch. Standard grade watches were commonly adjusted to 3 positions (dial up, dial down, pendant up) while higher grade watches were commonly adjusted to 5 positions (dial up, dial down, stem up, stem left, stem right) or even all 6 positions. Railroad watches were required, after 1908, to be adjusted to 5 positions. 3 positions were the general requirement before that time.

Marked For
Movements can be specially marked or engraved when produced for specific customers or purposes. When they are “marked for” railroad service or a specific railway, it can be noted in factory records. Also, when a clerk wished to note
something unusual about a run of movements, they might make notes here.