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Gary Wrote.  I don't know why you want to use the Polaris correction tables when you can just use the declination and the SHA to work the computation just like any other celestial computation.

I don’t want to get into any arguments of rule of thumb v smart phone apps, but to me a Polaris shot was a quick way of getting your latitude at night.  It kind of compares with a Mer-Pass Sun shot by day, except that’s only available around noon.  It was particularly applicable to bubble sextants. So as I see it SHA and dec Polaris for a particular date ought to be fairly easily obtainable, but obtaining a Q correction for use in the field might be more difficult.  Why not act as follows?

Obtain SHA and dec Polaris in advance from wherever. On graph paper mark a point P.  From centre P, draw a circle radius co-dec Polaris using the same scale as the graph paper.  Draw a line vertically down from P.  Where this line crosses the circle would be Q for LHA Polaris = 000, but we want to work with GHA Aries.  So, if the Earth rotates anticlockwise wrt space, space should rotate clockwise wrt the Earth. Therefore, place your Douglas protractor centre at P. and with the N arrow pointing downwards.  Mark off LHA Aries clockwise from the N arrow.  Next rotate your protractor clockwise until the N arrow lies along this new Aries line and mark off a further angle equal to SHA Polaris.  Note where this new line crosses the co-dec circle.  We could call this point X.  Read off the vertical value of X from the graph paper.  This is Q.  I’ll try and produce a decent diagram next time.  It’s still on the back of an envelope at the moment.  Once you know which quadrant your in, you could also find Q using geometry.  Now all you have to do is decide whether to add or subtract it from Hs.  "Why not act as follows?" Probably because I’m completely wrong.  I await comments.  DaveP