Catalogue of watches in the British Museum. VI Pocket Chronometers, Marine Chronometers and other Portable Precision Timekeepers. Early attempts to achieve accurate timekeeping with a non-precision escapement. The invention of John Arnold's pivoted detent escapement. Overcoming the shortcomings of the power source and gear train. Devices intended to eliminate the vertical positional errors. The Balance and spring and various parts associated with precision timekeepers. Technical data. Abbreviated references and Bibliography Concordance Glossary Index 176 plates. Very limited edition.
Edition : 1990