NavList:

Lars Bergman, quoting a paper by Sølver from 1945, you wrote:
"Then, apart from the traverse calculation, you only had the ancient method of magnetic variation, and although there is no evidence in written documentation so far known, we know after oral tradition that it has been regularly used. Thus told the late Professor Schwartz, Director of the Copenhagen School of Navigation, that in his youth — about 1850 — the masters of the Danish schooners that sailed with salt from St.Yves in Spain to Newfoundland and from there to Denmark with stockfish, understood only calculation of latitude, but knew nothing about longitude calculation by astronomical observations; there was no talk about chronometers for such people at all. They sailed on a north-west course in the Atlantic Ocean until reaching Newfoundland latitude, after which they followed this parallel of latitude westwards until the land came into view. An approximate longitude was calculated according to the traverse, i.e. by noting up the sailed courses and the speed measured with a hand log. Every time there was a good opportunity to do so, e.g. when the Polar Star was visible, observations of variation were taken to determine the longitude. "

Thank you! That's great, and it's one of the things I have been looking for. Crude longitude determination by observations of variation are just one step up from dead reckoning for longitude, and there were communities of navigators who were in that category, either because they were sailing centuries ago, or because, as in this case, they had no time for or interest in the more "scientific" forms of celestial navigation. Commentators on navigation marvel, with good reason, at "seat-of-the-pants" historical Polynesian navigation, but they often scoff in the same breath about the mindless and technically complex mathematics computations of "western" navigation. It's important to know, of course, that western navigation also had roots in some technologies that were closer to nature, especially the Earth's magnetic field, which was a uniquely European element of ocean navigation for centuries.

Continuing from my first post on this topic, I'm now trying to imagine a "minimalist" modern navigator doing an ocean crossing as an experiment or a challenge. What would be the minimal tool set for navigation by compass variation? Could we cross the North Atlantic today or maybe better, the South Atlantic --getting longitude or more generally a variation-based line of position-- without leaning on any electronic tricks...? And if we try it in the South Atlantic, we're denied Polaris, so what other options are available? Anyone have any thoughts? Please jump in... :)

Thanks again,
Frank Reed