Mechanical clocks came about in the Dark Ages to determine when church bells were to ring. Clocks of this period were weight-driven using gravity to unwind ropes from an axle. These first clocks were inaccurate, as the speed at which the ropes unwound was not well regulated.
Many individuals have participated in the development of modern watches. Charles V of France commissioned Henri de Vic in 1370 to build a large timekeeping device. Galileo applied the principle of the pendulum to regulate clock movements. In the late 15th century pendulum and weights were replaced by the coiled spring that unwound, driving toothed wheels. Watch making, as an industry, originated in Germany. Currently, the finest watch manufacturers are located in Switzerland.
Today a timepiece must be extremely accurate. Technology from computers to space travel requires perfect synchronization and timekeeping. This kind of accuracy and precision were unknown until the 1960s and the electric watch, using electronic circuitry and a quartz movement.
All watches have a movement, a mechanism that drives the hands or digital display. It must have a power source tiny enough to fit inside a case and still leave room for all the other parts. The two principal types of movements today are jeweled movements and quartz movements.
A jeweled movement is powered by a mainspring, using the same principle as the weights. After the spring is tightly wound with the winding stem, the coil gradually unwinds, running the watch. The unwinding powers the gears.
All spring-driven watches tick, although some are muted. The “tick-tock” is created by the alternate stopping and starting of the escapement. The escapement regulates the flow of power through the wheels and assures the transmission of power to the hands at a steady, precisely controlled rate.
The movement bearings are made from jewels (synthetic rubies), each milled, cut, and polished to a high degree of exactness. There are usually 7 to 23 jewels. More jewels does not necessarily ensure greater accuracy, though fine watches usually have more jewels. Used as bearings, jewels reduce friction in the watch.
Jewel movement watches can be regular-wind or auto-wind. In the automatic models, the mainspring is kept constantly wound by means of a small bar or rotor that moves at the slightest movement of the hand, wrist, or arm.
Manufacturers of electronic watches gradually did away with the escape wheel, pallet fork, and other moving parts, replacing them with an oscillating quartz crystal and sophisticated electronic circuitry. The electric watch does away with the balance wheel. Instead, a tiny tuning fork vibrates at a constant rate and amplitude.
In the electric watch, a small battery replaces the mainspring and other parts where tension and control interfere with timekeeping accuracy. Electric power is more accurate than the conventional spring-wound mechanism.
Shock-resistance is a feature of all quality watches. There is no way to make a watch movement “shockproof.” A watch is considered shock-resistant when a drop from one meter (about 40 inches), or the shock equivalent to that impact, will not a) stop the watch movement; b) damage the glass or crystal, bend the hands, or damage the case; or c) change the rate by more than 60 seconds per day.
Water-resistant watches are designed with special features to seal out moisture and allow swimming or bathing without risk of damage to the mechanism. Watches are tested to withstand water leakage at pressures experienced by divers under water. Such pressures are measured in “atmospheres.” An atmosphere is 4.7 pounds per square inch, or the amount of pressure at a depth of 33 feet of water. A watch rated at 10 atmospheres can withstand the pressure of water to a depth of 330 feet.
Calendar watches record the day of the month. In some cases, they are engineered to compensate for longer and shorter months and to give day of the week.
Chronograph watches have a center seconds hand that can be started at zero, stopped to record the time of an event, and then returned to zero by operating a button on the outside of the watchcase. They also have the ordinary hour and minute hands.
Chronometers are precision watches that have passed rigid tests for accuracy. (Chronometers should not be confused with chronographs.)
Moon phase watches display the current phase of the moon.
The strap-type band may be leather, simulated leather, plastic or fabric. It usually features a metal buckle or other closure.
The expansion type is available in silver or gold color and should "match" the watchcase. These bands vary greatly in durability and price.
The bracelet type comes in silver- or gold-colored metal. It may be sleek and shiny, textured to complement the watchcase, or woven.
dial – or face of the (non-digital) watch, which is the background for the hands and shows the time. Dial markings and hand styles vary greatly.
bezel – the part of the case that holds the crystal in place
frame – the center of the case, with end pieces or legs to which the watchband is attached
back – the part that rests on the wearer’s arm and can be either pressed or screwed onto the case
It goes without saying that watch values differ drastically by brand, such as Baume & Mercier, Bulova, Geneve, Longines, Movado, Omega, Patek Philippe, Piaget, Rolex, Seiko, etc. Values also vary based on the style (model) from each manufacturer.
All fine jewelry watches have a style and serial number. This information should appear on the receipt when you purchase the watch as well as on the appraisal.
Watches may contain gemstones, and the materials (gems and metals) can differ on bezel, case, dial, and strap. These variations may or may not be reflected in the style number, so an appraisal should describe in detail the metals and gems on each of these watch parts.
If you are buying a previously-owned watch, be sure the following statement is on your sales receipt:
“All watches have been personally inspected by the seller and watches,
watch parts, and accessories, including but not limited to bands, cases, bezels,
dials, and attachments, are genuine parts supplied by the watch manufacturer
(unless otherwise stated).”