NavList:

Dear George, Brad, and Wolfgang,

By reference to some just published most recent posts, and working the Aug 04th, 1773 Lunar example, with ONLY the published data and just the following assumptions :

1 - All observations performed at the same time. So, whatever actual Vessel's speed, Kermit will be happy :-)) , and

2 - All angular values corrected for Instrument error, and

3 - deltaT = +16.4 s

IF WE ASSUME HEIGHT OF EYE IS 0 FT, then get the following :

Lunar Distance Observation Time UT = 15h48m29s7, and
Observed position : S 20°28'18" / E 227°25'35", and

IF WE ASSUME HEIGHT OF EYE is 17 FT, then get the following results :

Lunar Distance Observation Time UT = 15h47m52s3, and
Observed position : S 20°53'30" / E 227°42'11", and

IF WE ASSUME HEIGHT OF EYE is 25 FT, then get the following results :

Lunar Distance Observation Time UT = 15h47m46.4, and
Observed position : S 20°57'36" / E 227°44'33"

These results should be consistent with Frank's on Line Computer results. They most always match and give 0.0' error on Lunar Distances when I process them with my resulting positions. No time to cross-check them now, and if any significant difference, I'm taking the blame again for some typo(s).

By the way, alternate position is way up north, somewhere in Siberia, so very limited chances to find any ship there, only Siberia "Wood Tigers".

I think that, for the time being, Paul Hirose also routinely achieves this kind of computations, and maybe Dave also ???

If we assume height of eye close to 20 FT, we then can observe a good agreement between published results and results mentioned here-above.

It is interesting to observe that most certainly the published heights are not corrected for either Augmented Semi-Diameter or Parallax, and that they are also most probably not corrected for height of eye either. I am not sure just from this example whether they have been corrected or not for Refraction, but since they apparently have not been corrected for HOE, and since HOE seems somewhere - to be confirmed - in the vicinity of 20FT, most certainly then such published heights have NOT been corrected for refraction yet.

Here comes my question to Wolfgang :

Wolfgang, if you have access to this entire (wonderful) document, and given the extreme care with which all these results have been BEAUTIFULLY printed at certainly a most expensive cost for the time, there should certainly be somewhere in this book, some detailed information which could give us this kind of definitive answer on this subject.

Thank you again to all

Antoine M. "Kermit" Couëtte

PS : For the time being - 45 minutes before High Tide time - , tide is REALLY high, although not threatening .... sigh of relief !!!

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