There isn't enough room on this page to cover everything, but it will get you started with the basics of jeweling, configuration styles, watch mechanics, movement sizes, winding and setting, types of dials, railroad standards, and more.
Watch this video to learn the basic parts of a watch and to see how the mainspring torque pushes through the gear train to power the balance wheel.
That ticking you hear occurs at a rate of 5 times every second ... 18,000 times an hour ... 432,000 times each day ... and 157,680,000 times a year.
Jewels were made from industrial-grade precious stones, such as rubies, garnets, sapphires, and even diamonds.
They were used as bearings for polished steel pivots that generated very little friction when properly oiled.
Hole jewels by themselves relied on the flat jewel face to control endshake. Balance wheels use hole and cap jewels, which trap the staffs by their pivot tips. Capped pairs generate less friction because smaller surface areas are in contact with each other.
Jewels were also used in the escapement. The roller jewel, mounted on the balance wheel, gives the impulse to the pallet fork, alternately locking and releasing the entry and exit pallet stones, allowing the escape wheel to rotate one tooth at a time.
A fully jeweled watch contains seventeen jewels - a total of seven for the balance assembly and a pair for each wheel of the gear train. In 1891 Hampden introduced the first 23-jewel watch in America, and the jewel race was on. Companies added jewels anywhere they could put them, like the mainspring arbor and a lot of unnecessary caps on the pivots.
Who had the highest jewel count? The Illinois Watch Co, with 26.
The purpose of jewels is to reduce friction between the gear pivots and the plates in which they rotated. Lesser-jeweled watches can be made to keep accurate time, but any unjeweled pivots of the gear train are still bare metal-on-metal against the plates.
Over time the pivots and the bushings can wear badly, especially with poor maintenance or in dusty environments, and once the plate bushings become enlarged the watch is essentially ruined.
Open face was the most common, with the winding stem at the 12:00 position, and was available in every size that American watch companies had to offer. This configuration eventually became a requirement as one of the primary railroad criteria.
Hunter (hunting) placed the stem at the 3:00 position, and was not railroad approved. The cases had a front lid that opened by depressing the crown, several hinges, a dust cover, and springs for the front cover and the latch.
Sidewinders are hunter movements in open-face cases. Seldom purchased this way historically, this arrangement means the original hunting case has likely been melted down.
Most collectors believe this configuration to be incorrect.
Conversion dials allowed hunter movements to be used in an open-face case by moving the seconds bit to the 3:00 position, returning the winding stem to 12:00. These began showing up after WWI, were usually made of metal or melamine, and could be railroad acceptable.
American watches used the Lancashire gauge, which is based on the dial plate of a O-size (zero size) watch measuring precisely a standard inch in diameter as a starting point, with each ascending size adding exactly 1/30th of an inch.
Pendant (or stem-set) is the most common. The watch is wound by twisting the crown; most mainsprings can go roughly 40 hours on a wind. The hands are set by popping up the crown, which did not meet the railroad requirements of the day.
Lever-set watches did meet railroad standards. Setting the time meant removing the bezel and pulling out a small lever, which could be in several different locations around the dial rim. The watch still gets wound by twisting the crown.
Key-wind and key-set watches also didn't meet the railroad requirements. The watch was wound with a small square key through the back and the hands were set by removing the bezel, although a few were able to also set the hands from the back.
Pin-set (or nail-set) watches were largely a Swiss innovation, and the design was seldom used by American companies. They were difficult to set, because the pin must stay depressed while turning the crown. The watch still gets wound with the usual method.
Accuracy was clearly the most important aspect of any watch, so high-grade movements were adjusted to keep better time. These adjustments offset the effects of friction and gravity by fine-tuning the balance assembly, and getting a watch to run accurately took many hours of work by a skilled watchmaker. Some companies simply milled 'Adjusted' on the plates with no definition of what that meant, while other firms included the total number of positions to which the watch was timed against, as well as isochronism and temperature adjustments.
A watch spends its days oriented pendant up or down, pendant left or right, or the dial up or down. There are a total of nine adjustments - the six positional ones, plus isochronism, plus one each for heat and cold.
The word means "same time" in Greek, and is the accuracy of a watch whether the mainspring is fully wound or almost spent. Barrel stopworks, counter-balanced pallet forks, and longer hairsprings with overcoils all helped to equalize mainspring torque in pocket watches. Early cone fusees didn't have this problem.
Changes in temperature affected both the hairspring and the organic oils in a watch, slowing it when cold. Bi-metallic split (or cut) balance wheels, which expanded or contracted depending on temperature, new synthetic oils, and the invention of alloy metals (Elinvar) in hairsprings in the 1920s all helped to offset this.
Porcelain-enamel dials were kiln-fired on a copper disc before the characters were added. Single and double-sunk dials were assembled from separate pieces, while one-piece faux dials had depressions milled into their backing plate.
Melamine dials arose from war-time shortages during World War II. An early laminate made with formaldehyde, dials made from melamine have a flat, dull appearance and surface cracks that will only worsen as the material deteriorates.
Aftermarket dials are legitimate items meant to replace damaged originals, made by Swiss firms like LaRose. The tip-offs are 5-minute markings that are too cherry-red, and dial sinks with incorrect diameters and indistinct edges.
Metal (embossed) dials were stamped, milled, or painted, and some were considered railroad grade as Hi-Visibility. Raised numerals, scenic settings, gorgeous patterns, and the fact that they can't crack are the benefits of metal dials.
The growing country moved nearly everything by rail in the 1880s, and with mounting pressure to reduce the amount of time between freights an accurate timetable was increasingly important. For many years different railroad companies had different standards and allowed different watches, but for decades had generally accepted any 18-size watch with 15 jewels. In 1891 the terrible Kipton, Ohio train wreck killed several people after two trains collided because an engineer's watch had stopped, and the rules changed.
Webster Clay Ball was appointed Chief Time Inspector and new accuracy standards were adopted. By the turn of the century a Railroad Grade watch had to be open-face, lever-set, either 16 or 18 size, have a minimum of 17 jewels, must be adjusted for temperature and positions, and made in America. It had to be equipped with a steel escape wheel and a micro-regulator, and front a bold-font Arabic dial. The most important attribute was that it had to be accurate to within 30 seconds per week, with trainmen and engineers being required to have their watches calibrated regularly.
Unoriginal balance jewels are the single most common indicator of possible damage.
Ruined balance weights mean the factory poise is lost, affecting positional accuracy.
Mismatched balance or gear train jewels are another sign of potential trouble.
An incorrect cock screw usually means that the original threads are stripped or enlarged.
Hairsprings are matched to balance wheels, so replacing it means re-timing the watch.
A mismatched screw means that the jeweler was too lazy to bend down and pick it up.