Lewis Caroll, blank maps and geoware

"He had brought a large map representing the sea,Without the least vestige of land: And the crew were much pleased when they found it to be A map they could all understand. "What’s the good of Mercator’s North Poles and Equators, Tropics, Zones, and Meridian Lines?" So the Bellman would cry: and the crew would reply "They are merely conventional signs! Other maps are such shapes, with their islands and capes! But we’ve got our brave Captain to thank" (So the crew would protest) "that he’s bought us the best— A perfect and absolute blank!"

Lewis Carroll, The Bellman’s Map (from The Hunting of the Snark, 1876).

The map is an ocean chart that allows the characters of the book to cross the ocean, hunting for "the Snark". The fact is that is only shows the ocean without any further details.

Why do I blog this? Stories about maps are always intriguing, this blank sheet of paper with navigational cues (N,S,E...) is very mysterious and may represent humans clueless about where they were located. But at the same time, a map that we can all understand.

More seriously, this is also about granularity, in the middle of an ocean this map is quite exact and accurate if there is nothing in the portion considered. Blank maps can be very often found when changing the granularity of online map applications, leading to this nonsensical situation.