Page from Limeneuretikè, sive portuum investigandorum ratio

According to Stevin, observations can best be made with a 'golden compass', invented by Reynier Pietersz. van Twisch (-1613). This instrument makes it possible to orient oneself regardless of the movements of the ship. Stevin, Simon, Limeneuretike Sive, Portuum Investigandorum Ratio, ex officina Plantiniana, Christophorus Raphelengius, Leiden, 1599, Museum Plantin-Moretus, inv. 4 269, p. 19.