A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Francis Upchurch
Date: 2014 Nov 28, 07:17 -0800
I've just built a simple prototype using your graphs. It only took about 20 minutes to make (takes days to make a slide rule) and much to my utter amazement, it seems to work!
See attached pics. It is just 2 paper copies of the dot graph baseplate stuck to either side of a plywood sheet. then rotors made from transparency film side A and B. Attached at pivot point with drawing pins. Obviously, this is only for "proof of princiople" test drive. I shall eventyually build a more robust version using acrylic sheets for the rotors. I don't know if you would be able to add the verniers and other extras from the Luykx paper? If so, I will wait for that before starting.
I tested the prototype using the example in Luykx. See pics. It Works well, even though slightly smaller (Xand Y axis just over 7.5 inches , whereas I think the original is 10 inches.) also no vernier which might make it more accurate.
Either way, it is incredibly easy and quick. I got Hc in under a minute. Faster than Bygrave or even calculator.
Cannot understand why this did not "take off" to excuse my pun!
It is so easy to build and use, I would be interested to hear what Gary thinks?
Thanks again Harri for the graphs.