Navigation Map adjuster of brass with a long and short leg; Map adjuster with two legs; each at the top semi-circular and split and hinged in such a way that the upper part of the legs forms a ring in the closed upper edge. The short leg is pierced and has a slit on the inside. Originally both legs had an iron point. Such a compass was used to adjust distances on the sea chart; Nova Zembla; Behouden Huys; Willem Barendsz; Jacob van Heemskerck; anonymous; c. 1590 - c. 1596; brass (alloy); filing; l 7.9 cm x w 3.3 cm