Harrison Decoded - Towards a Perfect Pendulum Clock

Editors: Rory McEvoy & Jonathan Betts

208 pages, illustrated

The book brings together the output of a forty-year collaborative research project that unpicked and put into practice the fine details of John Harrison's extraordinary pendulum clock system. Harrison predicted that his unique method of making pendulum clocks could provide as much as one-hundred-times the stability of those made by his contemporaries. However, his final publication, which promised to describe the system, was a chaotic jumble of information, much of which had nothing to do with clockwork. One contemporary reviewer of Harrison's book could only suggest that the end result was a product of Harrison's 'superannuated dotage.'

The focus of this book centres on the making, adjusting, and testing of Martin Burgess's 'Clock B' which was the subject of various trials at the Royal Observatory, Greenwich. The modern history of Clock B is accompanied by scientific analysis of the clock system, Clock B's performance, the methods of data-gathering alongside historical perspectives on Harrison's clockmaking, that of his contemporaries, and some evaluation of the possible influence of early 18th century scientific thought.

Table of Contents
1: Introducing the precision pendulum clock Rory McEvoy
2: The origins of John Harrison's 'Pendulum-Clock' technology Andrew King
3: Introducing Martin Burgess, clockmaker William Andrewes
4: Rescuing Martin Burgess's Clock B Donald Saff
5: Reflections on making clocks Harrison's way Martin Burgess
6: Completing Clock B Charles Frodsham et al
7: Adjusting and testing Clock B at the Royal Observatory, Greenwich Jonathan Betts
8: Crunching the numbers: analysis of Clock B's performance at Greenwich Tom van Baak
9: Decoding the Physical Theory of Harrison's Timekeepers Mervyn Hobden
10: Analysis of the mechanisms for compensation in Clock B David Harrison
11: Update on Clock B Rory McEvoy