# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

**Selection of slide rules, compendium of messages**

**From:**Gary LaPook

**Date:**2011 Nov 23, 22:36 -0800

http://www.fer3.com/arc/m2.aspx?i=108423&y=200905 http://www.fer3.com/arc/m2.aspx?i=108453&y=200905 http://www.fer3.com/arc/m2.aspx?i=108411&y=200905 http://www.fer3.com/arc/m2.aspx?i=108410&y=200905 ht For celnav I, of course, recommend my flat Bygrave. You can find everything you need to make one of your own for less than ten bucks here: https://sites.google.com/site/fredienoonan/other-flight-navigation-information/modern-bygrave-slide-rule Even if you want to use a standard ten inch slide rule then it is advantageous to use Bygrave's formulas and method since this produces more accurate results than the more common sine-cosine formulas. A test was don't and this was proven, see: http://www.fer3.com/arc/m2.aspx?i=108985&y=200907 Other posts about selecting slide rules. You can also go back in the archives to May 2009 where this was discussed. Here are links to some of those messages: tp://www.fer3.com/arc/m2.aspx?i=108370&y=200905 http://www.fer3.com/arc/m2.aspx?i=108361&y=200905 http://www.fer3.com/arc/m2.aspx?i=108346&y=200905 http://www.fer3.com/arc/m2.aspx?i=108342&y=200905 http://www.fer3.com/arc/m2.aspx?i=108344&y=200905 http://www.fer3.com/arc/m2.aspx?i=108660&y=200906 gl |