NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Bygrave position line slide rule
From: Zvi Doron
Date: 2004 Feb 28, 16:01 -0000
From: Zvi Doron
Date: 2004 Feb 28, 16:01 -0000
Hello, Henry Hughes & Son of London, England used to make a cylindrical 3 part position line slide rule for astro navigationsometims called "Bygrave" that worked on the principal of solving two right angle triangels instea of the complete PZX in one calculation. Francis Chichester used one on his epic solo flight across the Tasman Sea (1931) and Weems in his book "Air Navigation - British Empire Edition" gives a drawing and a few details. I could not find any reference to it on the web. Has anyone - ever used one? got one? seen one? knows if they can be had and for how much? Any information will be gratefuly received. Thanks Zvi
