The development of the chronometer is irrevocably linked to the intense rivalry and war among the British, French, Dutch and Spanish in the seventeenth and eighteenth centuries for domination of the seas to protect their trading vessels and expand their empires. Every ships captain had the same problem at sea, he could not establish his position within hundreds of miles to the east or west. The best solution seemed to be a clock to calculate how much the Earth had turned and thus accurately establish longitude. It would have to be as accurate on a pitching and tossing sailing ship as a precision pendulum clock on shore.
Each nation offered inducements to inventors. In 1714 the British government put up prizes totaling 45,000 pounds, worth over 2 million pounds today. The sum of 20,000 pounds was eventually won by a Yorkshire clockmaking genius whose first trade was carpentry. Over the years that followed, marine chronometers were developed and produced in large numbers. They are all collectors items today.
For many years Tony Mercer, grandson of the most enduring English maker, has studied and collected a large amount of information about these remarkable instruments that enabled explorers and the Royal Navy to map the world, the Navy to police it and merchant venturers to sail in relative safety. It would no be an exaggeration to say that the chronometer was one of the foundation stones of the British Empire.
The purpose of the chronometer is reviewed largely as a navigational aid for ocean-gong vessels, but also for survey, medical and other activities calling for precise time measurement.
A complete chapter is devoted to John Harrison, rightly described as maker extraordinary, giving a fascinating insight into his Herculean efforts to produce a timekeeper that would satisfy all the requirements of the Commissioners of Longitude. Other great makers including John Arnold, Thomas Earnshar, Le Roy, Berthoud, Frodsham, Dent , Kullberg and Tom Mercer are acknowledged for their evolutionary skills. Representative examples of chronometers and deck watchers by international makers - from the earliest known to contemporary instruments - are illustrated in both color and black and white.
A comprehensive list of makers and craftsmen brings together for the first time details of men who worked in the industry, their places of work and dates and serial numbers of their instruments. There is also an extensive bibliography.
