Navigation and the magnetic pole, 16th century. Geographer at work with navigational and maritime equipment and devices, including a celestial globe. Ships are seen in the background through the window. At lower left is a lodestone floating in a basin of water. This is an early form of compass, allowing navigation using the earth's magnetic poles. Artwork by Flemish artist Theodor Galle after Jan van der Straet (Stradanus). This illustration, dating from the 1580s, is from Stradanus's 'Nova Reperta' (New Discoveries).