A standard watch's basic purpose is to let you know the time of day. As watchmaker's skills improved and customers began demanding more from their timepieces, the chronograph was developed. These watches are recognizable by even the most casual observer of timepieces by their subdials, which add a sophisticated look to the watch's dial.
A chronograph is a watch with timekeeping capability as well as the ability to function as a stopwatch. A chronograph can be equipped with as few as one or as many as four sub-dials, depending upon the precision and design of the watch. Any watch that has a stopwatch complication is considered a chronograph, no matter how expensive or inexpensive the timepiece is.
The term chronograph is derived from the Latin words "chronos" and "graph" which mean time and chart, respectively. It is important to understand the difference between a chronograph and a chronometer when considering the purchase of one of these timepieces. A chronograph is any watch with a separate stopwatch feature, and its precision can vary; but chronographs tend to be very precise, as they are usually offered on high-end Swiss timepieces. A chronometer, however, is an officially certified chronograph whose precision has been tested. All chronometers are chronographs, but not all chronographs meet the exacting standards required to be certified as chronometers. A watch that qualifies as a chronometer will make it known on the dial, case or in the timepiece's literature.
Contrary to conventional wisdom, the chronograph did not originate in Switzerland. The first chronograph was developed in Paris in 1821 by watchmaker Nicolas Rieussec, and by 1822 the device was patented. The watch became popular with scientists, sportsmen and members of the military, and by the 20th century had become a staple of race car drivers and astronauts. In the 21st century, these timepieces are still used by the same types of people, but more often the chronograph is worn for its style, since chronographs are now available at more reasonable prices.
Most chronographs feature mechanical movements, with the stopwatch as a complication that makes them sought-after pieces of craftsmanship and engineering. These timepieces cost more than watches of similar quality without the stopwatch complication. Quartz, or battery-operated, chronographs also exist, as well as models that have a hybrid of the two, whereby a mechanical movement operates the chronograph, but the timekeeping mechanism is quartz.