The World of Visual Time Signals for Mariners: Time Balls, Time Guns, Time Lights and Other Signals

This book describes the worldwide evolution of land-based visual time signals that were used by mariners in the nineteenth and twentieth centuries for accurate navigation at sea. They followed development of chronometers which were carried in ships to show mean time at Greenwich, the chosen prime meridian. Greenwich time could be compared with local astronomical time to determine longitude, but chronometers were mechanical devices that had to be checked for accuracy. Land-based signals that were regulated by astronomical observations evolved from the ideas in 1818 of Robert Wauchope, a British naval officer who served at the Cape of Good Hope. He inspired introduction of time balls, specifically the time ball at Greenwich in 1833 which set the standard for subsequent installations and is still in operation today. The main emphasis is on the external appearance of time signals at different locations around the world and how they were used by mariners for rating chronometers. Time balls and guns also became popular signals for public use and workplace control but then had social and political implications.

Dr Roger Kinns was born in Winchester, England in 1944. He read Mechanical Sciences as an undergraduate at Gonville and Caius College, Cambridge and then took an MASc degree in control engineering at the University of Waterloo in Ontario, Canada, before returning to Cambridge to complete a PhD on unsteady aerodynamics.

Roger was Maudslay Research Fellow of Pembroke College, Cambridge, from 1971 to 1975. He then joined YARD Ltd in Glasgow, Scotland to lead development and application of techniques for the acoustic design of ships and submarines. He has worked as an independent consultant since 1999. Until 2019 he was a Senior Visiting Research Fellow in the School of Mechanical and Manufacturing Engineering at the University of New South Wales in Sydney, Australia. He has helped to supervise research students in acoustics at the Universities of Cambridge, Newcastle and New South Wales and has published widely in journals ranging from the Journal of Sound and Vibration to the Journal of Astronomical History and Heritage. The Maudslay connection led to an enduring fascination with the history of engineering and particularly time signals worldwide.

Presently, Roger is Treasurer of the Maudslay Society and Maudslay Scholarship Foundation, and Chairman of the Younger (Benmore) Trust that has supported development of Benmore Botanic Garden since 1928. He is also a member of the Newcomen Society, the Society for the History of Astronomy, the Royal Northern and Clyde Yacht Club, the Tasmanian Philatelic Society and the Incorporation of Gardeners of Glasgow, having been Deacon in 2009-2010. He is co-owner of Thalia, a racing keelboat built in 1924. It shares its name with the RN frigate which Wauchope commanded in the 1830s. Roger has lived in Clynder, near Helensburgh, Scotland since 1975.