Chronograph means a normal watch with a stop watch functions. A split chronograph, for example, means that your stop watch can stop while it keeps on timing internally, and then with a push of the button the stop watch hand will catchup to the current time. This is frequently used for calculating the finishing time difference between a race winner and the runner up.jliston48 wrote:I, for one, would be interested in seeing a wrist chronograph being used! Quite armless, I assume!!!conradin wrote:Mechanical watch/chronograph/stop watch legal? (on the bench or non shooting wrist?)
Maybe you mean chronometer.
My apologies for the liberty I took with your post!
Chronometer is a watch that passes certain timekeeping test to assure that it is extremely accurate in all sort of situation, for example, whether it is upside down, next to a magnet, under water, or extreme cold. It originally comes from the chronometer of a ship, ie, the marine chronometer, which is always in the captain's cabin, locked and sometimes guarded. The timepiece is extremely accurate and is floating inside of a jarful of water so that no matter which way the ship rolls in rough seas, it is always facing up due to gravity. The marine chronometer's time is usually the exact local time the moment the ship leaves its original port; or alternatively, the GMT.
Before the days of GPS, the only way to determine your latitude is by sextant and observation of the celestial bodies. But for longitude you need a timepiece. A captain will instruct a junior officer to bring a deck watch (a large pocket watch, that is also extremely accurate), and wait until the sun is at the very top, thus indicating midday at 12pm. The junior officer than set the deck watch at 12pm, came back to the captain's deck, and compare it with the marine chronometer's time. The difference of the time is the longitude.
An entire day consists of 24 hours, so each hour represents 15' of the 360' round earth, ie, 15' of longitude. To make my explanation simplier, the difference between the midday check of the deck watch and the time indicated by the captain's deck marine chronometer, is the time difference which also translates as the longitude difference between the current position and the original departing port. Along with the use of instrument like sextant, telescope, and observing celestial body, you can locate the ship's location on earth. Finally, to figure out where are you heading and to double check, you dump a floating device into the sea at the front of the ship with rope attached while the ship is sailing. When the item reaches the end of the ship you pick it up, and use the chronograph (stop watch) to figure out the speed of the traveling vessel, because you have both the stop watch time and the length of the ship. Coupling with the compass, you know exactly where you are going.
Good training of observation of celestial bodies can help to find out the exact time at night during travel. However, only one celestial body is always 100%, and that is the sun, which whenever it is at the highest point of the sky, it is midday at the particular location.
Hope this helps. I'm a trained watchmaker, so maybe my explanation is a bit too complicated and I try to use as many layman terms as possible.
As for chronometer for a match, I guess it won't hurt to wear a chronometer pocket watch (deck watch) with a chronograph function.
