A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2016 Oct 4, 11:49 -0700
Ed Popko, you wrote:
"By the Civil War, most vessels were equipped with chronometers, sextants and perhaps a quadrant. The American Nautical Almanac provided ephemeris data. LAN for latitude, time sights for local time and chronometer Greenwich were likely the mainstays. Lunars? Not likely any more."
Yes. And that's as we discussed in my "Celestial Navigation 19th Century Methods" class at Mystic Seaport which you've attended (by the way, for anyone reading along, this is being offered again in three weeks -- see my website).
There are some caveats to consider. What do we mean by "most vessels"? Every navigation culture contains sub-cultures. For example, if we're interested in "American" navigation, then we should split that at least between naval practice and merchant practice. I'll speculate that naval practice was more or less uniform whether the vessels were Union or Confederate since they were all trained at the same "schools", both formal schools and the schooling of practice at sea. To what extent had naval practice in the two American navies begun the transition from "Noon Sun and time sights" to "Sumner lines" (or other methodologies for generating celestial lines of position)? Also were there differences aboard steam vessels compared to pure sail vessels, which were rapidly passing into obsolescence?
You mentioned "LAN". Of course they used "Noon Sun" sights, which many navigators today call LAN sights, every clear day, but maybe it's worth noting that they probably would not have used that specific name "LAN" in the 19th century. Acronyms became all the rage in tech-speak in the mid-20th century.
Also, you said that they had the "American Nautical Almanac" for ephemeris data. Though this would have been an informal name in the Civil War period, the volume was actually the "Almanac for the Use of Navigators" or sometimes "Astronomical Ephemeris for the Use of Navigators", and it was simply an extract, the first half of the complete "American Ephemeris & Nautical Almanac" --quite different from a modern Nautical Almanac or even the American Nautical Almanac of the early 20th century. But did navigators use that? Union naval navigators almost certainly would have had access to that publication or the heavier complete volume. But what of Union merchant vessels and especially the northern whaling fleet, which was still probably the most significant American ocean-going fleet? And what did the Confederate navy use? In wartime, it may still have been easier to acquire a copy of the official British "Nautical Almanac" or a commercial printing of it. And of course many other commercial navigation manuals provided sufficient data for most nautical astronomy (as celestial navigation was known in this period) limited to the Sun and the bright stars.
And you wrote:
"So what were the common practices aboard blue water navy ships both north and south? I would appreciate any NavList-er's suggestion on where I could find out more."
Well, to a large extent, you answered your own question, right? That's what they did! :) If you're looking for statistical details on who used which methods and with what frequency, then I would say that's an academic paper that hasn't been written yet. But it's just the sort of thing that could make a nice graduate studies project for a student with an interest in the topic. There's plenty of primary source information available. Logbooks and other papers exist in vast, intimidating quantities.