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What are the parts of a watch? How old is my watch? The age of American watches can usually be determined from the name of the manufacturer and the serial number that appears on the movement. To see this information, you need to open the case of the watch and view the movement. For foreign watches the problem is a little more complicated. English watches often have hallmarks in the case of the watch and these can be used to date the watch to a specific year of manufacture. Continental watches sometimes have serial numbers, but often the only age information is from style elements and patent features that allow rough dating. Who made my watch? The maker of a watch is not necessarily the name that appears on the watch. American watch manufacturers would put a jewelers name on a watch for little or not cost if ten watches were ordered at the same time. An individual could get his name put on his watch for a small fee. Some mail order houses and other distributors sold a great many watches under their private label marking. Many of these large scale distributors such as the Burlington Watch Co. and the Santa Fe Watch Co. were supplied by the Illinois Watch Co. The best way to identify the maker of most American watches is through the Ehrhardt America diagrams (EA Diagrams) found in the various books published by Roy Ehrhardt's Heart of America Press. English watches were often made by someone other than the retailer who's name appeared on the watch. This was true even in the case of famous makers like Dent and Frodsham. Sometimes marks appear under the dial of these watches to give a clue to the actual maker. In some cases work books and factory records allow a serial number to be used to identify the actual maker. In the case of continental watches, it is convention to assume the maker was the person or company that did the final assembly of the watch and retailed it. However, almost all Swiss production and much of the French production was done from work that was carried out by a huge number of very small shops working under loose contracting arrangements. With some famous brands such as Gruen or Rolex, the actual maker is known because the final product was produced in an identified factory. How much is my watch worth? It is very difficult to assign values to watches that have not been personally examined. A proper appraisal requires a close inspection and experience on the part of the appraiser with recent sales and current market conditions. One way to estimate the value of a watch is to search the eBay on-line auction service for sales of similar items completed within the last 30 days. These results can still be misleading, but they provide some help. Another source of information are price guides such as the ones published by Heart of America Press and Shugart et. al. Because of the research nature of this web site, we do not provide on-line estimates of values. Some of the members who post frequently may be willing to furnish a rough estimate of value if contacted directly by email. What are jewels? Watch jewels are small bearings made out of precious and semi-precious stones. The gears of the watch works have small pivots on the ends of their shafts that turn in these jewel bearings. The gears may also turn in metal bushings or in holes made directly in the watch plates. All "jeweled watches" have 7 basic jewels consisting of two bearing jewels and two thrust or cap jewels that hold the balance staff in place, one jewel that is attached to the shaft of the balance to receive pushes from the lever and two jewels in the lever that engage the escape wheel. These parts can all be seen in the Elgin Brochure here on our web site. Additional jewels are used on each of the working shafts of the watch. If the watch has all the working shafts jeweled, the total is 5 additional pairs of jewels or 17 in all. Sometimes additional thrust or cap jewels are placed on the escape wheel and the pallet arbor to bring the total to 21 jewels. If the mainspring barrel is made so that the large gear connected to the barrel turns on a separate bearing, this can also be jeweled bringing the total to 23 jewels. Beyond these jewels, it is possible to put two more caps on the third wheel and one cap on the fourth wheel to bring the total to 26 jewels. It is also possible to add a cap jewel to the center wheel and two cap jewels to the barrel to bring the total to 29 jewels. None of these jewels beyond 23 provides any help to the working of the watch and it is arguable that more than 17 is unnecessary. What are the parts of a watch? The basic parts of a watch are the movement, the dial, the hands and the case. The movement has many parts to it, but consists of two plates or one plate and a set of bridges and cocks that hold the gears of the watch in place. Most modern watches have a mainspring that is wound up to provide power to the watch, a great wheel or main wheel that transfers the power from the mainspring to the center wheel pinion, a center wheel that carries the minute hand on its arbor and transfers power to the third wheel through the third wheel pinion, the third wheel transfers power to the fourth wheel that usually carries the seconds indicating hand on its arbor and transfers power to the escape wheel pinion. The escape wheel has special shaped teeth that interact with the pallets of the lever to transfer power to the lever. The other end of the lever transfers power to the balance through the roller jewel. The dial of a watch has hour and minute indications and may have additional circles for seconds and other functions such as state of winding indicators or calendar functions. When a dial is all painted on a single piece of material it is called a plain dial or "plain porcelain" when made of porcelain. If the seconds indication dial is made of a separate piece soldered to the main dial, it is called a single sunk or sunken seconds dial. If in addition the center of the dial is made of a separate piece from the ring containing the hours and minutes indications, the dial is called a sunken center or double sunk dial (if it has a seconds bit). Watches with the second hand running from the center with the hour and minute hand sometimes has sunk centers and no seconds bit. Dials can be made of metal, porcelain, hard porcelain and glass enamel. Glass enamel dials have a final clear enamel coating fired over the dial that gives a shiny water like finish to the dial. You can usually see the layer if you look at the dial from a sharp angle. The hands of a watch provide the indication of the time. Generally the minute hand of the watch should extend all the way to the outer line around the numbers of the watch. The hour hand is shorter and should extend just to the numerals of the watch. If the hands are out of proportion, they have probably been replaced. The two large hands will always be the same color. The seconds indicating hand will normally be the same color also, but there are frequent exceptions. When a watch has a center seconds function, there is normally a seconds indicating ring around the outside edge of the dial. The center seconds hand should extend to that ring. Watch cases break down broadly into Hunting Cases or closed cases and Open Face styles. An intermediate style is a demi-hunter that has a closed cover with a small window in the center so that the hands can be seen and has the hour indications engraved on the front cover. The watch case almost always consists of at least three pieces. The front cover or bezel, the back cover and the body. The watch movement is fixed to the body and the pendent usually is attached to the body. Some small modern watches have only two parts or have a body that completely enclosed in the front and back covers (depending on your point of view). If the back of the watch is hinged there is often another cover inside the back called the cuvette. Sometimes there is a cuvette when the back cover snaps on and off. Occasionally you will see a watch that has a bezel and a glass cover in place of the cuvette and less often one with a cuvette and a glass cover over the movement inside the cuvette. On the front side, if the watch has a closed cover it will almost always have a bezel inside the front cover to hold the crystal over the face of the watch. Rarely you will find a watch that has a bezel underneath the outer hinged bezel on an open face watch. This is done to protect the setting lever on lever set watches. What are adjustments? Adjustments are manipulations of the watch to improve its timekeeping during the period of running. The adjustments fall into three classes: Isochronism, Temperature and Position. Isochronism is the ability of the watch to keep time just as well when it is nearly run down as it does when it is fully wound. This is achieved by adjusting the power that the mainspring delivers to be as uniform as possible and by manipulating the balance spring so that the working portion of the spring maintains a uniform shape as it contracts and expands. The technique for doing this was worked out by John Arnold for helical springs around 1785 and by Breguet around 1805 for flat springs with an overcoil. The theory of the overcoil was developed by Phillips in the middle of the 19th century with the final developments by Lossier around the turn of the 20th century. Temperature adjustments are needed because the elasticity of the balance spring changes with temperature. There are also dimension changes in both the balance spring and the balance, but these are relatively small compared to the elasticity changes. The first temperature adjustments used bimetallic thermometers to change the length of the balance spring. These were eventually replaced by bimetallic balances invented by Arnold and largely perfected by Earnshaw. These balances still had problems with extreme temperature ranges and these were finally solved by the use of new alloys developed in the early 20th century such as Invar and Elinvar. Position adjustments are needed because the balance wheel in particular and other watch parts to a lesser extent are sensitive to running on the sides of the pivots as opposed to the ends. When a watch is laid down on a table, the gears are supported by the cap jewels or the shoulders of the pivots. When it is hanging from a fob or chain in a pocket, the gears are spinning on the sides of the pivots. If the watch is well adjusted for Isochronism, the problems are relatively small. However, hanging the spring sideways instead of flat can cause similar problems with effects on the rate of the watch. Position adjustments usually consist of small changes to the shape of the overcoil of the balance spring. They may also involve slight flattening of the pivots of the balance (but many consider this cheating). Adjustments beyond the basic three of dial up, dial down and pendent up, are only made on the balance spring and are arcane at best. Adjustment to 5 positions includes pendent left and pendent right. Adjustment to 6 positions adds pendent down. How does a watch keep time? The basic timekeeping function of a watch depends on the interaction of the balance mass and the balance spring. The balance mass provides inertia so that once the balance is moving (spinning) it tends to continue until some other force makes it stop. Eventually friction would make it stop, but in a watch, the stopping force is the tension that builds up in the balance spring as it gets wound up by the spinning balance. When all the inertial force has been transferred to tension in the balance spring, the spring begins accelerating the balance in the opposite direction. As the spring unwinds to its resting position, the balance gains inertia and winds the spring in the opposite direction until it once again stops due to the tension in the spring. The rate at which the balance and spring oscillate in this manner is determined by the stiffness of the spring and the inertial properties of the balance (its moment of inertia) that are dependent on the mass and shape (mostly diameter) of the balance. The balance and spring will oscillate at their natural rate once they have been pushed in one direction or another. Eventually friction will stop the oscillation. All the rest of the watch is there to overcome the friction losses in the balance and spring. In a lever watch, the mainspring is connected to a small lever through a series of 4 gears and a special wheel called the escape wheel. The small lever holds the escape wheel in place with one of its pallets until the balance trips the lever as it passes through the balance spring's neutral position. When this happens, the escape wheel pushes against the lever and it in turn pushes against a small jewel mounted on the shaft of the balance. Once the lever has pushed the balance, it continues to move until it once again locks the escape wheel. At this point everything is once again in a resting state except for the balance. When the balance swings back the entire process is repeated moving in the opposite direction. In order for people to be able to use the watch to tell time, the 4th wheel usually carries a small hand to indicate seconds and the second wheel (center wheel) carries a hand to indicate minutes. An additional pair of gears under the dial provide motion for the hour hand. How do I open my watch? This depends on the way your watch is held in its case. The number of case styles and mechanisms is pretty varied, but a good explanation is given by Kent Singer on his helpful page on opening watch cases.
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