A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2011 Feb 19, 14:11 -0800
I am teaching two celestial navigation classes at Mystic Seaport in Mystic, Connecticut next month. I am quoting from the Mystic Seaport descriptions so where you see the phrase "the instructor" below, that's me!
We had a number of NavList members at last year's classes, and I would be very happy to see some of you there this year. :) Last year one class filled up, and the other was about two-thirds subscribed, so don't miss out. PLEASE NOTE: to sign up for these classes, visit the web page for the Treworgy Planetarium at Mystic Seaport's web site here:
Note the "underscore" character in that address before the letters "cw". The links to register for the classes are at the upper right on that web page.
"CELESTIAL NAVIGATION: 19th-CENTURY METHODS"
Sat/Sun March 19-20.
"A two-day weekend class devoted to the history and practice of celestial navigation as it was done aboard the whaling vessel Charles W. Morgan during the second half of the 19th century.
Students will learn details of the practical techniques, both the sight-taking methods and the mathematics, of navigation using the Sun and stars aboard 19th century sailing vessels. The instructor, who has extensively studied the navigation methods in the surviving logbooks of Mystic Seaport's whaleship Charles W. Morgan, will recount some of the history of the whaling voyages and teach students exactly how the Sun and Moon were used to navigate in the 19th century. The Charles W. Morgan, currently undergoing an extensive three-year restoration, is not only the centerpiece of Mystic Seaport's collection, but also a prototypical whaling vessel of the 19th century. The celestial navigation methods used aboard the Charles W. Morgan were typical of most American whaling vessels in this period. After this class, students will have in-hand the practical skills of 19th-century navigation, fun and useful for practical navigators, navigation enthusiasts, as well as the professional or armchair historian.
This class is appropriate for adults as well as younger students with good basic math skills. If you can add and subtract, you can do celestial navigation. A basic understanding of latitude and longitude are the only prerequisites for this class. Traditional 19th-century celestial navigation occasionally uses technical astronomical and mathematical terminology like right ascension and logsecant, but have no fear, all of these will be explained.
Students will learn how to take and clear a meridian latitude sight for "latitude by Noon Sun", the single most important sight in the history of celestial navigation. Students will also learn how to take and clear a "time sight" or "longitude by chronometer" sight which was the workaday method of 19th century navigation. Students will also be taught basic sight-taking procedures using an actual 19th-century brass sextant or ebony octant from the instructor's personal collection.
This class isn't just "about" navigation. You will walk away with the skills to do it yourself. A student who completes this two-day course will be proficient in the basic skills of 19th-century celestial navigation and could successfully navigate across an ocean today, with a good dose of luck, using these historical methods. Students will also have an understanding of the navigation of the Charles W. Morgan, as it was actually done, as seen in the primary source evidence of the surviving logbooks.
DAY ONE: two three-hour sessions. Topics covered: Noon Sun, 19th-century approaches to Noon Sun sights, latitude sailing, the essential aspects of finding longitude, navigation on the Charles W. Morgan's maiden voyage 1841-45 as understood from the logbooks. An opportunity to take actual sights, weatherpermitting.
DAY TWO: two three-hour sessions. Topics covered: review of altitude corrections, applies to latitude and longitude sights. Clearing a time sight using simple tables, how to practice 19th century navigation in the 21st century, the limitations of these methods and their relationship to modern navigation, navigation on the Charles W. Morgan's last 19th-century voyage as understood from the logbooks, an opportunity for sight-taking, weather-permitting."
"EASY INTRODUCTORY CELESTIAL NAVIGATION BY NOON SUN"
Sat/Sun March 26-27.
"A two-day weekend class (second day optional) teaching how to use a sextant and how to find latitude AND longitude using simple observations of the altitude of the Sun at noon. This is a modern technique based on classical celestial navigation. It is ideal as a GPS backup. It is also fashioned for the sextant enthusiast interested in using the instrument to get a real position fix without the time and expense of a ten-week course. This is a method of celestial navigation that is easily learned and easily re-learned. Like riding a like, once you've learned it, you can pick it up again, either in an emergency situation or just for fun with just a few minutes' work.
Students will learn how to use and adjust a sextant. We will also provide advice on buying sextants on ebay and elsewhere and how to avoid "counterfeit" sextants. Students will learn how to get latitude and longitude using sights at, and around, local noon. You will also learn how to correct for vessel motion, a critical detail frequently omitted in well-known textbooks and other resources. This class isn't "meta" navigation (not a class "about" navigation); it's real navigation. Students will take away the knowledge and the skills to navigate using sextant observations of the Sun at noon almost anywhere on Earth. A good backup for that rare day when the GPS (and the backup GPS) fail.
DAY ONE: two three-hour sessions. Topics covered: the behavior of the Sun at noon and its connection with navigation, use and adjustment of a marine sextant, latitude by the Noon Sun. Practice with sextants, sight-taking opportunity (weather permitting).
DAY TWO: two three-hour sessions. Topics covered: altitude corrections required for accurate latitude,
longitude by sights around noon and statistical issues. Correcting for vessel motion, essential for a
proper fix. Practice with sextants, sight-taking opportunity (weather permitting). This class is appropriate for adults as well as younger students with basic math skills. If you can add and subtract, you can do celestial navigation. A basic understanding of latitude and longitude are the only prerequisites for this class."
So to summarize, that's "19th century methods" in four weeks, "easy intro by noon sun" in five weeks.
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