"Hey jw, didn't you know that "geometry" means "earth measuring"? And that it was invented by the ancient Greeks to help them navigate? :-)"<br><br>Yes, and Yes. But the last thing I want to do in an emergency situtation is pull out a table and try to find my direction/inclination/declination/altitude/whatever using it. You can simply use a stick, a watch, a piece of string, etc. to do the exact same thing without using math. Very interesting thread though, something I definately want to explore!<br><br>John McIntire