A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2012 Jul 12, 10:56 -0700
Bryan, you wrote:
"I have many questions about CN and only a basic knowledge of the practice."
Any questions you may have will yield many answers and much conversation here. As I think I said to you in email some weeks ago, there is no better place online for discussions of celestial navigation. So ask away! Just dive right in. :)
Could you maybe tell us a little more about your classes and what you hope to, and need to, achieve? Vinalhaven is a tiny place. How many students do you have? What age ranges? What ranges in mathematical ability and interest do you need to address?
The great thing about celestial navigation is that you can teach aspects of it at multiple levels. There's no end to the options. Some students may want to learn the instruments and the practice with little theoretical background. There's still math in that. The altitude corrections for dip and refraction have plenty of good mathematics and physics in them. Others may find "spherical trigonometry" fascinating and take no interest in actual practice. Still others may be fascinated by the historical development. There are nearly endless calculational tools and tables to be explored. And in addition, there are very modern technological tools, like various star-finding apps on Smartphones, which can connect you to 21st technology and get your students thinking about the math underlying those tools, too.
A trap to avoid: late 20th century celestial navigation, as it stood around 1975, is treated by some celestial navigation enthusiasts as a "perfect system". And indeed it had reached a plateau in development with little prospect for further improvement (a unique kind of perfection!). But this leads to a ritualistic approach to the subject that's bad education and probably bad navigation, for that matter. Many of the tools were no longer developed, not because they were perfect, but because they were completely obsolete. Yet some navigators and navigation educators insist on using them because "that's how it's done". A good specific example of this is the old "HO-2012D Star Finder". It's a device I wouldn't wish on anyone, guaranteed to turn the fun of learning constellations into a mechanical activity. But it's in the books, so many recent navigation students fall into the trap of believing that it is a tool that they must use if they intend to be "real" navigators. That is ritual. On the other hand, I should add that some navigation enthusiasts simply find the old "HO-2102D" fun for its own sake. And of course, to each his own. :)
You should pick up a few books. John Karl's "Celestial Navigation in the GPS Age" includes a lot of math and also good practical advice. It emphasizes solutions by common "scientific calculator". John is also a member of NavList, so if you have any questions you can contact him here. Susan Howell's "Practical Celestial Navigation" is still popular. I also highly recommend David Burch's "Emergency Navigation" which is much more than the title suggests. David Burch is also a NavList member. Ken Gebhart, who owns "Celestaire", a major retailer of sextants and all manner of navigational equipment, books, and other tools, had published a short booklet on basic celestial navigation for high school level education. He may still have these available. The approach is minimalist, but you can have students measuring altitudes with a protractor and finding a rough position fix using circles of position drawn on a globe within just a couple of hours. And of course, Ken Gehbart is also a member of NavList.
You can download numerous historical books related to celestial navigation from Google Books and also archive.org. I maintain a rather large list of these which you can access at the top of the main NavList message boards web page. Here is a direct link to that list: http://www.fer3.com/arc/navbooks2.html. Of them, you should grab an edition of "Bowditch" (The American Practical Navigator). If you have the patience to download a few, I would recommend the editions from 1837, 1888, 1920, and of course the most recent from 2002. Another 19th century navigation resource, highly recommended, is Lecky's "Wrinkles in Practical Navigation". And finally for something historical but more recent you may want to find a copy of Mixter's "Primer of Navigation" from the 1940s. Since it's more recent, it's not available online, but it's not hard to find on the used book market at a reasonable price via amazon.com or abebooks.com (a separate visit to the latter may be redundant).
Please understand that summer is always a quiet time for NavList. Most of our members are northern hemisphere inhabitants, and this is boating season. Nonetheless, if you start asking interesting questions, they will find time after their days on the water to reply to you on the NavList message boards. So if it starts off slowly, don't worry.
And welcome aboard!
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