NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Norm Goldblatt
Date: 2013 Mar 31, 11:10 -0700
Alan- Yes, after all these years, everything moves smoothly. It's made of plywood and, as in a 'real' slide rule, the 'fit' can be adjusted by loosening the end plates that hold upper to lower scales. The center scale slides in tongue and groove.
As far as expansion, in general, if everything expanded uniformly,and equally, it shouldn't affect the result. You could argue that since the material is inhomogeneous, expansion may be more or less in some places. That would be easy to check by simply aligning the scales and check if all the markings remained aligned (easy for us humans, because of vernier acuity AND ability to communicate) as temp-humidity is changed.
I bet the guys who made the 300+ footers could tell us all about this problem
Norm
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