This map of the western hemisphere may be based on a 1648 map produced by the renowned Dutch cartographer Joan Blaeu. It shows North and South America and part of one of the islands of present-day New Zealand. Parts of Canada and Alaska were still completely unknown at this time.
Additional information:
In 1742 astronomy teacher Martinus Martens was commissioned to produce a new map for the floor because the original one was showing signs of wear and tear. He probably looked at the latest French maps, adding the changes they showed to the original map. The new map was not inlaid in the floor until the 1950s.