Marine and Pocket ChronometersMarine and pocket chronometers, pocket watches with tourbillons or carousels form, in the large family of clocks, are a small group of very precisely running timepieces with little sensitivity to external influences, such as variations in temperature. Watch historian Hans van Bertele discusses the fascinating development and history of the chronometer, portrays the most important manufactures in short biographies, and reports on the great voyages of