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George H, you wrote:
"Come off it, Frank! That method would, at the very
best, be half as accurate (or twice as inaccurate) as
longitude-by-lunar. So if he could achieve an accuracy of 6 miles
either way, a devout lunarian could correspondingly claim 3 minutes
for a longitude. Both would be related to the unrealistic claim of
angular-distance measurement to 0.1 arc-minutes. Just because some
observations on one occasion, from on land, fell within that bracket
does not imply any such accuracy; as Frank, with a scientific
background, should be well aware."

Well, come off it, George (back at ya)! Your recent experience with
sextants is minimal. Unless something has changed radically, your best
instrument is a cheap, plastic Ebbco sextant [for those unfamiliar, you
can get an old one for about $30 on ebay --they're nice low-accuracy,
backup sextants]. Do you think it's possible that your experience is
tainted by the mediocre accuracy of that tool? I sure do. Additionally,
can you tell me how many times you have watched beginners use a good
metal sextant to shoot a lunar distance? Have you organized sextant
meetings that you're not telling us about??

You also wrote:
"And three of us have asked Frank to show how a position is to be
deduced from a pair of such observations, showing the working. I have
presumed that any delay in responding was because Frank was working on
the details of how to formalise it. We were offered a nice graphical
picture of intersecting cones, but that was not what had been asked
for. Is that all we're going to get?"

George, I explained how to do this TWICE in this thread. In fact, Dave
W. followed the steps I gave and posted his own fix to the list which
differed a couple of miles from mine. But not everyone understands
things in the same fashion. I will think over it tonight and see if I
can come up with an explanation of the clearing process suited to your
unique needs. Now, why don't you see if you can duplicate Dave W.'s
success... Take the observations that I posted earlier, work up two
lines of position, and see where they cross. You do agree, I hope, that
this problem amounts to crossing two lines of position. It's really not
complicated AT ALL.

A general comment:
George, we all know that you have severe 'allergic reactions' to new
ways of looking at celestial navigation. Basically, every time I've
brought up something new on this list in the past three years, you have
sunk into a state of denial, usually launched by a post saying that I
am not answering your questions the way you want them answered. But
you're missing out here, George... There's more than meets the eye in
celestial navigation.

-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars


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