NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Lunar Distances: Graphic Methods
From: Frank Reed CT
Date: 2004 Apr 24, 13:21 EDT
From: Frank Reed CT
Date: 2004 Apr 24, 13:21 EDT
Heny H wrote:
"It was not my intent to advocate any method of solution as respects any navigational problem"
I didn't interpret that you were advocating any method.
And:
"There have been enough methods of solution to satisfy most any taste in celestial navigation, however, in the final analysis, practical skill in use of the sextant, or whatever, becomes the governing factor, whether it be in measurement of altitude, lunar distance, horizontal angle, or otherwise, as no method will correct for a bad observation."
Or a bad sextant, or a badly adjusted sextant... One of the things I've noticed when people first start shooting lunars is that they are surprised by the quality problems they encounter (there are a couple of these on the list today). Often it's not an observational problem per se, but a sextant adjustment problem. Do you remember anything like that when you experimented with lunars on your South Atlantic passages?
And wrote:
"I seem to remember it having been Bowditch's intent to reduce the mathematics of
navigation to the understanding of every seaman aboard his ship -including the cook - although I do question his success rate."
The story of the cook is famous and it's in the intro to modern editions of Bowditch. It seems likely to me that Bowditch, or his publisher, was as much a salesman and promoter as a mathematician and navigator. It is surely true that you can teach anyone to shoot and reduce lunars or any other celestial sight. But why? Who needs a ship full of lunarians? When you think about it in p.r. terms, though, it makes sense. A story like that sells books. It also helps to establish the idea that Bowditch's lunar method is easier than the rest (if even a cook can do it). Many people interested in navigation still believe today that this was Bowditch's contribution --an easier method of reducing "difficult" lunars. The case that it is really easier in any practical sense is very weak. There are many, many "easy" methods, and most of Bowditch's lunars methods were borrowed or lifted from other works with minimal attribution.
And wrote:
"I also was not aware that we were going to start a thread on lifeboat navigation"
Well, that was just a little joke. I thought about putting a 'smiley' next to it, but in this case I felt it was clear that it was just a funny. I had this image of a navigator hauling one of those large celestial globes over the side as his ship is going down. Hey, if it's made of the right material, it might float on its own!
And Henry H wrote:
"on the subject of which I may have a few earthy comments - my sextant box is still fitted for backpacking while going down a manrope in a heavy sea."
I, for one, would love to hear more about this. Did you ever find yourself in desperate circumstances taking celestial sights from a lifeboat??
Frank E. Reed
[ ] Mystic, Connecticut
[X] Chicago, Illinois
"It was not my intent to advocate any method of solution as respects any navigational problem"
I didn't interpret that you were advocating any method.
And:
"There have been enough methods of solution to satisfy most any taste in celestial navigation, however, in the final analysis, practical skill in use of the sextant, or whatever, becomes the governing factor, whether it be in measurement of altitude, lunar distance, horizontal angle, or otherwise, as no method will correct for a bad observation."
Or a bad sextant, or a badly adjusted sextant... One of the things I've noticed when people first start shooting lunars is that they are surprised by the quality problems they encounter (there are a couple of these on the list today). Often it's not an observational problem per se, but a sextant adjustment problem. Do you remember anything like that when you experimented with lunars on your South Atlantic passages?
And wrote:
"I seem to remember it having been Bowditch's intent to reduce the mathematics of
navigation to the understanding of every seaman aboard his ship -including the cook - although I do question his success rate."
The story of the cook is famous and it's in the intro to modern editions of Bowditch. It seems likely to me that Bowditch, or his publisher, was as much a salesman and promoter as a mathematician and navigator. It is surely true that you can teach anyone to shoot and reduce lunars or any other celestial sight. But why? Who needs a ship full of lunarians? When you think about it in p.r. terms, though, it makes sense. A story like that sells books. It also helps to establish the idea that Bowditch's lunar method is easier than the rest (if even a cook can do it). Many people interested in navigation still believe today that this was Bowditch's contribution --an easier method of reducing "difficult" lunars. The case that it is really easier in any practical sense is very weak. There are many, many "easy" methods, and most of Bowditch's lunars methods were borrowed or lifted from other works with minimal attribution.
And wrote:
"I also was not aware that we were going to start a thread on lifeboat navigation"
Well, that was just a little joke. I thought about putting a 'smiley' next to it, but in this case I felt it was clear that it was just a funny. I had this image of a navigator hauling one of those large celestial globes over the side as his ship is going down. Hey, if it's made of the right material, it might float on its own!
And Henry H wrote:
"on the subject of which I may have a few earthy comments - my sextant box is still fitted for backpacking while going down a manrope in a heavy sea."
I, for one, would love to hear more about this. Did you ever find yourself in desperate circumstances taking celestial sights from a lifeboat??
Frank E. Reed
[ ] Mystic, Connecticut
[X] Chicago, Illinois
