An extremely rare boxwood navigation "Pleinschaal" from around 1700.
Ref.:
17314
A boxwood "Pleinschaal". Overall length 32 cm, width 3 cm. On one side inscribed: "H.Schoenmaker", most likely the name of the Sea-Captain who owned the instrument. On one side 4 different scales and 6 small brass studs to accomodate a dividers point. On the other side 2 additional scales. The pleinschaal was the predecessor of the "Gunters rule" and used exclusively by Dutch rea-farers.