NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Capt Cook Navigation....
From: Maurice Millard
Date: 1998 Jun 09, 6:15 AM
From: Maurice Millard
Date: 1998 Jun 09, 6:15 AM
Rory Edge wrote: .......Cook's use of the moon to navigate. The method seems to have worked rather well. Does anyone know of a book that describes the method in detail? One very good recent article written by Cameron Bright, is in the Jan/Feb 1994 Issue of Ocean Navigator. This gives a good overview on the history and application of the "Lunar Distance" method. Last year in the Journal of the Institute of Navigation, there was an article discussing the navigation techniques used by Joshua Slocum in his circumnavigation. The conclusion was he had used lunar distances and the article goes on to discuss the technique including sample almanac pages. In my readings, after the introduction of chronometers, I find no sign that the time method became universal. The Royal Navy adopted the method, and they had a significant infrastructure designed to support it. Naval depot's had "Chronometer Workshops' from which navigators drew a chronometer prior to a voyage. After the voyage the unit was returned for checking and calibration. This units could not have been cheap by any means. I think an apt analogy would be the use of Ships Inertial Navigation Systems (SINS) on ships in the 1960s. These systems were very expensive, but they offered significant tactical advantages to Navies and hence were worth it. SINS did not find any application in commercial maritime circles. I think an indication of the popularity of Lunars is the fact that Lunar Distance tables continued to be printed as part of the Nautical Almanac's into this century. As I recall the French almanacs carried this data up to about the 1912 editions. Again opinion: What finally killed "Lunar Distance" method? I think it was due to faster ships; the time between ports was less. Most ports dropped a ball at midday (this is where the Times Square New Year thing comes from) allowing navigators to check chronometer error. This allowed much less expensive mechanisms to be used with acceptable results. One final note. Cook was assigned an astronomer as part of the crew for the voyages of discovery. No doubt it fell to this individual to do the tedious work of sight reduction required by the LD method. Maurice Millard =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-= =-= TO UNSUBSCRIBE, send this message to majordomo@ronin.com: =-= =-= navigation =-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=