NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Poor Line of Position Computer/popularity of slide rule sight reduction
From: Hein Bodahl
Date: 2010 Jan 15, 17:00 +0100
From: Hein Bodahl
Date: 2010 Jan 15, 17:00 +0100
On 15.01.2010 14:54, Brad Morris wrote: > How does the Poor Line of Position computer compare in > accuracy to a Bygrave or to the more accurate tabular methods? From the book: http://ia351430.us.archive.org/3/items/simplifiednavig00poorgoog/simplifiednavig00poorgoog.pdf "With this instrument the calculations are actually performed with a few direct and simple movements, and with an accuracy equiva- lent to that obtained with four place logarithmic tables." > What about the speed of solution? "A comparison of these three methods shows the following number of book openings and aux- iliary figures necessary in each to obtain the re- quired altitude and azimuth: Logarithmic 8 openings and 45 figures. Aquino 2 openings and 64 figures. Mechanical 1 opening and 4 figures." and "With this instrument the calculation of the al- titude, as required by the Saint Hilaire method, is reduced to four (4) simple and direct move- ments, while the azimuth may be found by two (2) movements. The entire calculation is made on the instrument, the work is straight-forward and requires the writing down of one figure only." Could maybe give an idea. Just ordered the book on amazon. Hope it has the foldout of the computer. Hein