NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: UNK
Date: 2014 Nov 24, 09:04 -0000
Thanks Harri,
Yes , I was confused by the different methods described in the Brown and Luykx papers. The Smithsonian model looks similar to the one described by Luykx, so I’ll try to build a prototype of that and then try both methods to see which works best. Thanks for the “flipped” rotor. That is a good name for it!
Best wishes
Francis
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Harri Ojanen
Sent: 23 November 2014 15:11
To: francisupchurch@gmail.com
Subject: [NavList] Re: Brown-Nassau CN Plotter
Hello Francis,
It is nice to hear that you liked the diagrams. Also good that you pointed out the paper by Lyukx, I had missed that one. Now I got a view of the rotor on the other side also. I wasn't sure which way it is flipped, but now that is clear. There is no problem in creating the diagram for the other rotor also.
Lyukx gives a different description about how the device is used compared to Brown and Nassau. According to Lyukx the rotors are used twice, first to find altitude, then again using altitude to find azimuth. In the description in Brown and Nassau both altitude and azimuth are found in a single step. The rotors shown in the Lyukx paper and in the photo of the device in Smithsonian are missing what Brown and Nassau call azimuth lines. I wonder why the difference. Perhaps azimuth rules became too complicated when the one-step approach was used?
The other things you mentioned are also certainly doable, like the verniers. It takes just some time to do them. I'll post updates of the diagrams, and also the program to create these.
Cheers,
Harri
