Caert-Thresoor was a compact, pocket-sized atlas that combined maps and illustrations with short descriptive texts. It first appeared in 1598 under the imprint of Barent Langenes in Middelburg, with copies available for sale through the Amsterdam publisher Cornelis Claesz. Conceived as an affordable and portable alternative to large-format atlases, it brought together terrestrial, maritime, and cosmographical material in a form intended for both learned readers and a broader public.

The maps and illustrations were engraved chiefly by Pieter van den Keere (#285, #383), with substantial contributions by Jodocus Hondius (including the present plate, #294, #296) The authorship of some plates, including the East Indies map (#388), remains uncertain and may involve either engraver.

This small double-hemisphere celestial map depicts the northern and southern skies populated with mythological representations of the constellations, drawing on the Ptolemaic celestial tradition. Within the atlas, it functions as a cosmographical counterpart to the terrestrial maps, reflecting contemporary ideas about the ordered relationship between the heavens and the Earth.

Framed by decorative strapwork, the image is numbered “9” in the upper right corner, indicating its sequence within the atlas, and marked “A 5” in the lower right, the printer’s signature, denoting the fifth leaf of section A.

Peter van der Krogt, ed., Koeman’s Atlantes Neerlandici, vol. 3 (’t Goy-Houten: HES & De Graaf, 1997–), 376-381 (no. 341:01).

Günter Schilder, Monumenta cartographica Neerlandica, vol. 7 (Canaletto, 2003), 457