Watches that bear a chronograph on their face are highly sought after, but often not for functional purposes.
The reason being this is simple: it is a stopwatch.
In essence, thats all a chronograph ever is.
via louismoinet.com
A stopwatch that is mounted onto the face of an ordinary watch.
They were wound and would run until they stopped.
The ability to stop and mark time was entirely new.
Thus, the first chronograph/stopwatch made for public consumption was refined.
In fact, it would go on to change how all races were measured, includingairplaneflights and car races.
In 1844, watchmaker Adolphe Nicole made this advancement, which has continued on chronographs to this day.
Depending on how they are built, they can time longer or shorter periods to meet your needs.
This wasa tachymeter, which is another item that is often added to watches, yet rarely used.
A tachymeter is a fixed set of numbers that go around the face of a timepiece or chronograph.
What those numbers tell you is how many times something will occur in an hour.
Most tachymeters begin at the 7.2 second mark on a chronograph with a 500.
Notice that the distance is irrelevant.
Any event that is being timed can then be measured.
This is a simple formula which reads:T = 3600/t
This isnt as difficult as it appears.
The small t is the amount of time it takes something to occur.
Thats the amount of time it took to move that foot.
The 3600 is the number of seconds in an hour.
Thats where the number on the tachymeter comes from.
The same is true for every number on a tachymeter.
Measuring races is the obvious answer, but the less obvious answer comes from NASA.
They did this using chronographs on the watches they were required to wear.
