Causa aestus maris
Causa aestus maris is a 1590 Latin treatise on ocean tides and circulation, printed in Ferrara by Benedictus Mammarellus under the name of Pandolfo Sfondrati. The single picture is a woodcut printer's ornament: an oval cartouche framed by crossed keys, a papal tiara, grotesque masks and scrolls, with a diagonal zigzag band inside. A designer could draw on its symmetrical framing devices, mask faces and interlaced strapwork for borders and heraldic-style frames.
