This essay is the winner of the Baroness Burdett-Coutts's Prize for the best essay on the balance spring and its isochronal adjustments. It provides a detailed analysis of the balance spring and its role in regulating the accuracy of watches and clocks. This book is a must-read for anyone interested in horology and the history of timekeeping. This work has been selected by scholars as being culturally important, and is part of the knowledge...