Molyneux' remarkable map, circa 1590, dropped the vast imaginary continent, and displayed a small tongue of land in about the region where the real Australia is; suggesting that some voyager had been blown out of his course, had come upon a part of the western division of the continent, and had jotted down a memorandum of its appearance upon his chart.

It looks like a sincere attempt to tell a bit of the truth.

But speaking generally, the Terra Australis of the old cartographers was a gigantic antipodean imposture, a mere piece of map-makers' furniture, put in to fill up the gaping space at the south end of the globe.
A few minutes devoted to the study of a map of the Indian Ocean, including the Cape of Good Hope and the west coast of Australia--especially one indicating the course of currents--will show how natural it was that Portuguese and Dutch ships engaged in the spice trade should occasionally have found themselves in proximity to the real Terra Australis.

It will also explain more clearly than a page of type could do, why the western and north-western coasts were known so early, whilst the eastern and southern shores remained undelineated until James Cook and Matthew Flinders sailed along them.
A change of the route pursued by the Dutch on their voyages to the East Indies had already conduced to an acquaintance with the Australian coast.
Originally, after rounding the Cape, their ships had sailed north-east to Madagascar, and had thence struck across the Indian Ocean to Java, or to Ceylon.

As long as this course was followed, there was little prospect of sighting the great continent which lay about three thousand miles east of their habitual track.