Until the middle of the XVIII century the sailors did not have precise methods for its location in the ocean. Therefore, they often strayed a long time, and sometimes lost in the depths of the sea. To remedy the situation the British Parliament in 1714, announced a reward of 20 thousand pounds to anyone who would be able to find a way to determine longitude to within half a degree. Among other scientists engaged in this problem the British watchmaker John Harrison. After many successes and failures, he created a marine chronometer H-4, which won the award.

Girard Perregaux manufactory released in honor of engineer hours ww.tc John Harrison. U chronometer round body of 18-karat white gold. On an enamel dial depicts travel route from Portsmouth to the English at Port Royal (Jamaica) and back, which made ​​the son of John Harrison to test the reliability of H-4 hours. Circulation of the series – 50 copies.