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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: chronometer dials: 12 or 24 hours?
From: George Huxtable
Date: 2009 Jan 19, 20:20 -0000
From: George Huxtable
Date: 2009 Jan 19, 20:20 -0000
The attached picture should answer Clive's worry about the difficulty of reading a 24-hour clock. This clock has stood at a gate of the Royal Observatory, Greenwich, for over 150 years. It's actually an early electric "repeater" from a master clock. In my view, the only problem about reading it is in the multiplicity of Is, Vs, and Xs that are called for by the use of Roman numerals. If ordinary numerals had been used, it would have been much clearer. It relates, a bit, to earlier discussion, in that the moment of passing 24 hours must have been changed, at some date, from midday to midnight. Probably when Greenwich time changed, at the start of 1924. Note that at the very top mark, the dial is not labelled XXIV (=24), but 0, something that all our 12-hour dials could usefully follow. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---