NavList:

Mark Coady, you wrote:
"It did indeed appear to kick out the known duffer sight...and put me almost dead on, as my variations happened to be minor +/- for the other three. It appeared to prove which sight was best, and It appears I could have taken an altitude and time from the average line instead of the actuals and been really happy as well."

That last bit is one of the unsung virtues of running a line (of pre-determined slope) through a set of sights, whether it's lunars or just ordinary altitudes. It gives you the option to use an average or any convenient point on the line. Typically, you would pick off a value at a convenient "round number" for the time, maybe an even minute value. For example, an average of sight times might turn out to be 18:23:47 UT, but a point on the line could be read at 18:24:00 UT, and the latter is easier to work with --at minimum it reduces the probability of a typo or a transcription error. That time, 18:24:00, also decimalizes easily to 18.4 exactly, and that can help with interpolation and other calculations. Anything on a multiple of six is nice!

You asked:
"Would this line slope technique be considered applicable to all Lunars with our wobbly moon, so long as the sights are a close series within the hour or so? "

Yes within an hour you should have no problems unless the distance is very short or the star is well off the ecliptic. If you clear each sight separately and then run a line through the GMT values, this isn't a concern, but with lunars at distances below twenty degrees or at high angles from the Moon's motion (the ecliptic nearly enough), there are non-linearities that arise from the changing geometry of the triangle on the sky. As for the non-linearities in the Moon's acual motion, these are not significant even over the course of several hours. A little historical proof of this is the fact that the lunar distance tables were published with the data given at three-hour intervals. Linear interpolation between those values worked fine --again, ignoring the cases where the geometry relative to the other body is a problem. Certainly, for the case of Moon-Sun lunars, where the minimum distance is always greater than about 30 degrees and the Sun almost directly in line with the Moon's path on the celestial sphere, the linearity over three hours is a safe bet.

Frank Reed