NavList:

I'm trying to figure out how to determine Longitude by timing a lunar occultation of a star. I think it should be possible with just a known LAT, Latitude an almanac and a stopwatch but have not been able to find a good explanation of how to do it. The 1861 American Practical Navigator gives a method as does THE MARINER’S LATITUDE & LONGITUDE READY-COMPUTER BY 'I‘IIOMAS BEVERLEY, 1836. However, both of these are quite difficult to follow. I also have Jean Meeus Astronomical Algorithms which must have the answer somewhere. I thought I was close working it out from first principles but seem to need to iterate to get to an answer. The Astronomy community looks at the problem from the viewpoint of known position which does not help. Can anyone help me by pointing out a suitable source of an explanation please? Maybe I'm on a wild goose chase but it seems an interesting problem. It all started with the Occultation of Aldebaran on Sept 5th, as it was thick cloud there's a little time to resolve this before the next one ;-)

By the way it's amazing what the 19th Century seafarer was expected to be able to understand and follow.

Thanks

Bob Crawley