Technically, the chronograph is a watch with a mechanism which enables intervals of time, ranging from fractions of a second to 24 hours and more, to be measured and visualised. The name “chronograph” (from the Greek chrónos, time, and gráphein, to write) was created in 1821 and its etymology recalls the origins of an instrument associated with the world of horse riders who wanted to record the performance of their thoroughbreds. The first chronograph wrote the time, because the hand deposited a dot of ink on the dial when operated at the start and finish of the time being measured. Although the hand was not stopped, the number of seconds that had elapsed between the first dot and the second one could be read on the dial.
The most fundamental development of the chronograph was made by the Swiss Adolphe Nicole, who in 1862 patented a device in which the seconds hand was stopped, returned to zero and then started again when a second measurement was required. The time intervals elapsed were no longer written, that is indicated with dots of ink, but only seen, by observing where the hand had stopped.
Celebrating a relationship which goes back to the twenties, Officine Panerai has renewed its own historic link with the Swiss manufacture Minerva, using its sophisticated calibres in some prestigious Special Editions with a vintage character. The OP XXV chronograph calibre is developed from the Minerva 13-22 calibre, a hand-wound movement 12¾ lignes in diameter with a balance wheel which makes 18,000 vibrations per hour, like the Angelus movement that was used in the first prototype of the Mare Nostrum.