Early explorations of the southern celestial sky

In this paper the astronomical explorations of the southern celestial sky by Dutch navigators at the end of the sixteenth century are investigated. It is shown that the main motivation for this scientific enterprise stemmed from Dutch cartographic tradition and interests, represented first and foremost by Petrus Plancius and the competing globemakers Hondius and Blaeu. It is shown, too, that at the time actually two surveys were carried out. We have investigated the results of the two surveys by analysing the data presented on celestial globes by Hondius and Blaeu, and in the star catalogue published by De Houtman in 1603. It appears that only after the first survey was it recognized that the stars of the well-known Southern Cross constellation could be matched with stars already recorded by Ptolemy.