Note 3 — THE CIRCLE OF THE SCIENCES.

“Mercator’s Chart.” In all the charts in use before Mercator’s, curved lines were drawn representing the meridians and parallels. A vessel which followed these lines always receded too far from the equator, and, if land did not intervene, would describe a spiral course and finally reach the pole. Mercator constructed a map as follows: A line, AB, was drawn representing the equator, and was divided into 36, 24 or 18 equal parts for meridians at 10°, 15°, or 20° apart, and the meridians were then drawn through them perpendicular to AB. The distance of the parallels and the tropics, and the arctic circles were marked from the equator on the sides, and these points joined by straight lines. The map does not give a natural representation, as the polar regions are immensely exaggerated. The distortions in the form of the countries and the relative distances of places are rectified by making the degrees of latitude increase proportionably to those of longitude.