chronographs

A chronograph is a timekeeping instrument that combines a standard time display with a stopwatch function. In a typical chronograph, the main dial continues to show the current time, while pushers on the case control a separate mechanism that starts, stops, and resets elapsed-time counters, usually displayed on one or more subdials. The central seconds hand is often used to measure elapsed time when the chronograph is engaged.

The modern chronograph originated as a mechanical device in the 19th century. Nicolas Mathieu Rieussec is credited with inventing an early form in 1821 that recorded elapsed time using ink on a rotating dial. Over the 20th century, wrist chronographs became widely adopted for sports timing, aviation, and other professional applications, leading to a broad range of designs and improvements.

Mechanisms and features vary, but a typical configuration includes a central chronograph seconds hand, subdials for minutes and sometimes hours, and pushers at the 2 o’clock and 4 o’clock positions. Many models feature a tachymeter scale for calculating speed or distance based on time. Some chronographs incorporate advanced functions such as a flyback mechanism, which instantly resets the elapsed time without stopping the main timekeeping, or a split-seconds (rattrapante) function for timing multiple intervals.

Terminology distinguishes chronographs from chronometers. A chronograph denotes the stopwatch capability, while a chronometer is a timepiece that has undergone official testing for high precision. Many chronographs are not chronometers, though some models bear both designations. Today, chronographs are produced in mechanical, automatic, and quartz forms, spanning luxury and mainstream markets and serving a range of timing needs.