Mr. Lapook,

You wrote here that computations I made ("invented") were generally beyond knowledge of of the era sea/air navigators. Certain calculations however , were for them as old as the hills , like computing the LHA (always of the true sun) and the GHA of a heavenly body. Strictly within these limits of skill we (and any navigator henceforth) can establish sunrise time , no N.A.listing ,no rounding , no formulae , in the roads of Howland as described in EJN-2008 / 2011 :

GHA @ 159-07-E 071545 GAT 288-56-18

GHA @ 178-47-W U.L.sun horizon add 87-45-40

________

201-10-38

subtract from 360-00-00

________

In orbit travel of true sun 158-49-22

Divide by 15 deg / hr 10h35m17s

Add : GAT of sunset @ Nukumanu Fix Add 7-15-45

_______

GAT U.L. sun in horizon 17-51-02

Add 03m50s Equation of Time 03-50

_______

GMT of sunrise U.L. 17-54-53

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The sunset fix appears in detail in EJN-2011 , the sunset fix is recomputed , in somewhat other terms as above , in EJN-2008.

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That's nice.

I guess that I should be impressed by your mathematical abilities except that in your two published papers you said that Noonan would have calculated the times of sunrise and sunset by the much simpler method of interpolation of the times in the Nautical Almanac sunrise/sunset tables. You have now had to invent this new, complicated method of computation after I demonstrated to you that your interpolation of the sunrise table method (and you were sure of that one and resisted for some time) doesn't work. I have over 40 editions of the

~~American Practical Navigator~~, going all the way back to the first edition written by Bowditch in 1802. I scanned and sent to you excerpts from the 1863, 1888 and 1914 editions as examples showing that none of them show your sunset/sunrise method for finding longitude. I have reviewed all of my editions (I am not going to scan in any more of them) and, you'll have to take my word for this, none of them contain your sunrise/sunset method for determination of longitude or your newly invented way for calculating that time. They do contain other methods for determining longitude, time sights, lunar distances, eclipses of Jupiter's moons, lunar eclipses, charts of magnetic variation, etc., the list seems pretty complete so I am surprised I found no mention of your method that you claim was standard and known to all navigators.

The American Practical Navigator has been

the standard navigation reference book for American navigators since 1802. Noonan was an American navigator so we can expect that he would have been knowledgeable of it content. But, by the time he was practicing navigation, all of the longitude methods that I just mentioned had become archaic and were no longer in use, having been replaced by the universal use of the LOP (Sumner line) so he would not even have used the time sight, which was the last method of longitude determination deleted from the

American Practical Navigator.

In the past I have asked you to provide the books that you claim contain your methods and you have refused to do so, I have shown you mine but you haven't shown me yours. So, I am not going to continue this conversation with you until you do.

Gary LaPook