As will be seen hereafter, Flinders helped to show that the passage existed.
There were also many smaller points requiring investigation.

Cook in running along the east coast had passed several portions in the night, or at such a distance in the daytime as to render his representation of the coastline doubtful.

Some groups of islands also required to be accurately charted.

Indeed, it may be said that there was no portion of the world where, at this period, there was so much and such valuable work to be done by a competent and keen marine explorer, as in Australia.
A passage in a manuscript by Flinders may be quoted to supplement what has been written above, as it indicates the kind of speculations that were current in the conversation of students of geography.* (* Called an Abridged Narrative--Flinders' Papers.) "The interior of this new region, in extent nearly equal to all Europe, strongly excited the curiosity of geographers and naturalists; and the more so as, ten years after the establishment of a British Colony at Port Jackson on the east coast, and the repeated effort of some enterprising individuals, no part of it beyond 30 leagues from the coast had been seen by an European.

Various conjectures were entertained upon the probable consistence of this extensive space.