Maritime chronometers are rare and precious items, crafted with care and precision, to provide an accurate means of measuring time and determining longitude at sea. Developed in the eighteenth century, these beautiful instruments were produced for the next two hundred years to the same design, and played a significant role in the growth of maritime trade, ultimately helping to shape the world as we know it today. In The Marine Chronometer, the author explains the workings of the chronometer and highlights some of the most significant makers and provides hints for maintenance. Topics covered include: -The problem of longitude -The early sea clocks -Developments in France and England -The mechanism of the chronometer -Caring for chronometers AUTHOR John Cronin studied horology at Bradford Technical College, where he was awarded a gold medal and a British Horological Institute prize for the national exams, before being elected to Fellowship of the Institute. John was the winner of the 1994 Artist Craftsman competition of the Worshipful Company of Clockmakers and is now closely involved with ICON [the Institute of Conservation]. He is one of just ten horologists who have gained accreditation with the institute as professional conservators, and is the only member specializing in chronometer work. SALES POINTS * Provides a comprehensive history of this intriguing piece of navigational equipment * An invaluable reference work for maritime history enthusiasts and clock collectors * Explains the working of the chronometer and provides hints for care and maintenance * Superbly illustrated with 146 colour photographs * John Cronin is a Fellow of the British Horological Institute and is one of only ten horologists with the Institute of Conservation ILLUSTRATIONS 146 colour photos *

The dramatic human story of an epic scientific quest and of one man's forty-year obsession to find a solution to the thorniest scientific dilemma of the day--"the longitude problem." Anyone alive in the eighteenth century would have known that "the longitude problem" was the thorniest scientific dilemma of the day-and had been for centuries. Lacking the ability to measure their longitude, sailors throughout the great ages of exploration had been literally lost at sea as soon as they lost sight of land. Thousands of lives and the increasing fortunes of nations hung on a resolution. One man, John Harrison, in complete opposition to the scientific community, dared to imagine a mechanical solution-a clock that would keep precise time at sea, something no clock had ever been able to do on land. Longitude is the dramatic human story of an epic scientific quest and of Harrison's forty-year obsession with building his perfect timekeeper, known today as the chronometer. Full of heroism and chicanery, it is also a fascinating brief history of astronomy, navigation, and clockmaking, and opens a new window on our world.

The Marine Chronometers at Greenwich is the fifth, and largest, of the distinguished series of catalogues of instruments in the collections of the National Maritime Museum. Housed at the Royal Observatory Greenwich — the 'home of time' and the Prime Meridian of the world — this extraordinary collection, which includes the celebrated marine timekeepers by John Harrison (1693-1776), is generally considered to be the finest of its kind in existence. The book is however much more than just a catalogue, and includes an accessible and engaging history of the chronometer, revealing why these instruments were important in our scientific and cultural history, and explaining, in simple terms, how they worked and were used. A comprehensive Glossary and Bibliography are included to ensure any technicalities are explained and that the reader has suggestions for useful 'further reading'. Over 480 photographs and illustrations, including many fine macro-photographs and line drawings, illustrate the 'jewel-like' beauty of the chronometer's construction and explain the function and subtleties of its mechanism. A chapter on 'How the Chronometer was Made', describes the fine sub-division of labour used to create these special machines, from bare metal, right up to delivery on board ship, and brief biographies of the makers tell the human story behind this important nineteenth-century industry. Another chapter, 'The Evolution of the Chronometer', aimed at collectors, historians and curators, provides clearly structured information on assessing and dating the chronometer, something many find difficult. And, for the dedicated specialist, there is extensive tabulated data on the technical structure of this important collection, a unique resource for future research.

If you want to know where you are, you need a good clock. The surprising connection between time and placeais explored inaTime and Navigation- The Untold Story of Getting from Here to There, the companion book to the National Air and Space Museum exhibition of the same name. Today we use smartphones and GPS, but navigating has not always been so easy. The oldest "clock" is Earth itself, and the oldest means of keeping time came from observing changes in the sky. Early mariners like the Vikings accomplished amazing feats of navigation without using clocks at all. Pioneering seafarers in the Age of Exploration used dead reckoning and celestial navigation; later innovations such as sextants and marine chronometers honed these techniques by measuring latitude and longitude. When explorers turned their sights to the skies, they built on what had been learned at sea. For example, Charles Lindbergh used a bubble sextant on his record-breaking flights. World War II led to the development of new flight technologies, notably radio navigation, since celestial navigation was not suited for all-weather military operations. These forms of navigation were extended and enhanced when explorers began guiding spacecraft into space and across the solar system. Astronauts combined celestial navigation technology with radio transmissions. The development of the atomic clock revolutionized space flight because it could measure billionths of a second, thereby allowing mission teams to navigate more accurately. Scientists and engineers applied these technologies to navigation on earth to develop space-based time and navigation services such as GPS that is used every day by people from all walks of life. While the history of navigation is one of constant change and innovation, it is also one of remarkable continuity. Time and Navigation tells the story of navigation to help us understand where we have been and how we got there so that we can understand where we are going.

A tale of eighteenth-century invention and competition, commerce and conflict, this is a lively, illustrated, and accurate chronicle of the search to solve “the longitude problem,” the question of how to determine a ship’s position at sea—and one that changed the history of mankind. Ships, Clocks, and Stars brings into focus one of our greatest scientific stories: the search to accurately measure a ship’s position at sea. The incredible, illustrated volume reveals why longitude mattered to seafaring nations, illuminates the various solutions that were proposed and tested, and explores the invention that revolutionized human history and the man behind it, John Harrison. Here, too, are the voyages of Captain Cook that put these revolutionary navigational methods to the test. Filled with astronomers, inventors, politicians, seamen, and satirists, Ships, Clocks, and Stars explores the scientific, political, and commercial battles of the age, as well as the sailors, ships, and voyages that made it legend—from Matthew Flinders and George Vancouver to the voyages of the Bounty and the Beagle. Featuring more than 150 photographs specially commissioned from Britain’s National Maritime Museum, this evocative, detailed, and thoroughly fascinating history brings this age of exploration and enlightenment vividly to life.