Flutterby™! : A Whole New World 2005-04-14 14:27:15.50075+00

A Whole New World

2005-04-14 14:27:15.50075+00 by petronius 3 comments

According to the Times of London, Christies is offering for sale the oldest known map that shows the coast of the Americas and the Pacific, dated 1507. Considering that it took 4 months each way to sail to the New World from Europe, this is a lot of data to gather in a little over a decade. What intrigues me is the projection used, which even 500 years ago was making an attempt to render the continents in their true relative sizes. This is true state of the art imaging for the 16th century, the equivalent of our getting pictures back from the Huygens probe. (Sorry about the tiny picture, but Christies hasn't yet posted a better one. Maybe our imaging systems still need work.)

It's actually a "Globe gore" that was designed to be cut out and applied to a globe. This particular map is described in detail on pg. 42 of Flattening the Earth: Two Thousand Years of Map Projects by John P. Snyder. Waldseemuller was one of several cartographers to resurrect the design of projections in the early 16th century, leading to Mercator in the late 16th century. Ptolemy's projections predate this one by over 1300 years but were still in widespread use until this time.

One of the things that Jonathan Raban

talked about in Passage To Juneau

was how bad longitude measurement was even in 1873. Despite the work on refining clocks in the early 1700s and Harrison's breakthroughs, the most reliable systems still involved a lot of astronomy, so its rather amazing to see that they had most of the continents in roughly the right place in the early 1500s.

According to the Times story, the Waldseemuller map was the product of a research project, where a number of scientists and specialists were brought together to consolidate all the information available. I wonder if they sort of averaged out the reports of various mariners, which might give you a fair idea of where you were. Of course, if longitude was chancy even in 1873....but then, didn't the US Navy have a submarine smack head-on into an uncharted seamount just a few months ago? I understand the Board of Inquiry didn't blame the skipper, but I imagine his career was flooded in all compartments.