De Zeevaert, oft, Conste van ter zee te varen,
De Zeevaert is a 1580 navigation manual by Pedro de Medina, printed in Antwerp by Hendrick Hendricksen for sailors and ship's pilots learning to cross the sea by instrument and table. The page shows two circular compass-style diagrams with radiating divisions above two columns of printed numerical tables with Roman numerals and Dutch headings, set in a dense, ruled layout a designer could borrow for dial-and-grid schematics.
