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Re: Mendoza's method for clearing lunars.
From: George Huxtable
Date: 2004 Aug 4, 18:18 +0100
From: George Huxtable
Date: 2004 Aug 4, 18:18 +0100
In a message to the list, earlier today, I asked for help about the following question. "There's a further minor-matter arises, in which any members who has access to a pre-1828 version of Norie's may be able to help. In Norie's 1816 text about Mendoza's method, which I quoted earlier, He mentions adding "the proportional logarithm of the Moon's correction (XXX)". In my own, early 20th century edition of Norie's, table XXX just gives the Moon correction, in minutes and seconds, not the proportional log. of that correction. This presents no real problem, because there's a table of proportional logs elsewhere, so the required number can be found by a two-step procedure. It seems that even as early as 1828 (in the Mystic version), Norie's table XXX was the same as in mine. So I ask if anyone can tell me if, in an earlier version of Norie's, (perhaps in the edition current in 1816) table XXX contains the Moon correction in minutes and seconds, or whether it contains the proportional log of that correction, so the step in Mendoza's method can be mode in one go. Conceivably, it might offer columns for both. Perhaps I have simply misunderstood Norie's text about the Mendoza method, and he intendedd a two-step lookup from the start. Please don't send me copies of that table XXX: just a few words about what it contains, is all I am after." ================= Now I find, after a more careful reading of Norie's text, and examining the layout of his standard form for lunars, that I was indeed misunderstanding what Norie was stating. In a list of items to be added together, one of those items was- "the proportional logarithm of the Moon's correction (XXX)". I had taken that to read that table XXX contained the proportional log of the Moon's correction: but the evidence shows that to be wrong. What he was saying was that you should use table XXX to find the correction, then use another table (XXXIV, in fact, though Norie doesn't say so) to obtain the prop. log. of the correction. With that meaning, it's no surprise that table XXXV remained the same in the early 20th century as it was in 1816 and 1828, and there's no discrepancy with Norie's standard form for calculating lunars. All is now understood, and I withdraw my request for help on that matter. George. ================================================================ contact George Huxtable by email at george@huxtable.u-net.com, by phone at 01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ================================================================