There was actually some logic behind the nautical mile. In the 1870s when time zones were first being introduced a choice had to be made regarding the prime meridian there were two candidates Greenwich and the French equivalent. At the time the best maps were British and that swung the day. Also, clocks had 12/24 hours, not 10, so 360° was a better choice than 400.
Ther you are blame it on our duodecimal clocks. _____ From: [email protected] [mailto:[email protected]] On Behalf Of Pat Naughtin Sent: 07 June 2010 06:37 To: U.S. Metric Association Subject: [USMA:47527] Nautical measures On 2010/06/06, at 17:12 , Martin Vlietstra wrote: For many years the Daily Telegraph quoted the height of high tide at Dover in feet without the benefit of a metric conversion, even though the height indicator at the Dover docks was only in metres, the admiralty charts were in metres and the published tide tables were in metres. Dear Martin, One of the (several) reasons that the French metric committee chose to use the Earth as a standard for the length of the metre was that they lived in an age when shipping and world exploration were extremely important issues. They intended that the measuring of angles in grades and the measuring of distances in metres and kilometres would drastically reduce the complexity of nautical calculations. Consider a quadrant of the Earth divided decimally. 1 quadrant = 100 grade = 10 000 kilometres 0.1 quadrant = 10 grade = 1000 kilometres 0.01 quadrant = 1 grade = 100 kilometres 0.001 quadrant = 0.1 grade = 10 kilometres 0.000 1 quadrant = 0.01 grade = 1 kilometres etc. Unfortunately sailors decided not to go with the simplicity of the decimal metric system so the transition to the metric system didn't work so far (from 1770 till 2010). People 'who go to the sea in ships' still cling to the pre-1770 measuring words. They continue to use: nautical miles for distance knots for for wind speed knots for vessel speed feet for vessel length inches for rope diameter etc. Perhaps your example is simply another example of irrational conservatism. Cheers, Pat Naughtin Author of the ebook, Metrication Leaders Guide, that you can obtain from http://metricationmatters.com/MetricationLeadersGuideInfo.html PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com <http://www.metricationmatters.com/> for more metrication information, contact Pat at [email protected] or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.
