1el norte geográfico
- There had been hopes that the variation of the compass - the angle between the directions of magnetic north and true north - might do the trick, since it was known to vary with position on the earth.
- Oddly, the surveyor used magnetic north in laying out the site, whereas the nearby streets were laid out on a true north bearing.
- An example of the former is that the Bermuda Triangle lies on the 80° meridian, a line that is one of two places on Earth where the magnetic and true north poles are in perfect alignment.
- During his expeditions in the Americas and Europe, he recorded and reported on magnetic declination - the angle between magnetic north and true north at a particular location.
- The eastern side of the Great Pyramid, for example, points only three arcminutes away from a true north - south line, and other pyramids in the group are not much worse.