File talk:Maslens Inland Sea of Australia.jpg

The Australian historian Michael Cathcart shows (The Water Dreamers 2009) that there is no factual basis for the popular claim that most Australian explorers were searching for an inland sea. The only official explorer who seriously believed that there was such a sea was Charles Sturt'.

This map is often used as evidence of this supposedly popular belief. But, as Dr Cathcart points out, this is a very poor source. The author of this map was not Australian and had never been to Australia. He was an Englishman named John Maslen who lived in Yorkshire. What is more, even his belief in the inland sea was very short-lived.

In fact, Maslen published two versions of this map. He had it drawn in 1827 with the title 'The Great River or the Desired Blessing'. As the map shows, he believed the common theory that the westward flowing rivers of New South Wales drained into a great river which flowed across the continent to the northern coast. The map also allowed for the existence of a great lake - as well it might - but this lake was not what excited Maslen. He thought that the river was a manifestation of divine grace.

In 1830, he published the map in his book The Friend of Australia. By then, Maslen had been swayed by a newspaper report that Aborigines had told a grazier that there was a great lake in western New South Wales. As soon as he could, Maslen amended the map to produce the version shown here. The only difference between the two is that he scrubbed out the words 'Desired Blessing' and labelled the lake 'Supposed Sea'.

However, it didn't end there. In 1836 he published a second version of his book in which he explained that he had been wrong about the great lake theory and that evidence pointed to the great river after all.

There are two great ironies to all this. Firstly, the Aborigines' advice to the grazier had been correct: there is indeed a series of great lakes in western New South Wales known as the Menindee Lakes. Secondly, Charles Sturt's belief in an inland sea was based on sound geographical thinking. As Sturt realised, a river could not flow across the continent of Australia because the inland is depressed - like the middle of a saucer. If water did flow into the middle of Australia it would accumulate there, forming a lake. That lake exists. It is now called Lake Eyre. But, because Australia is so arid, the lake is almost always dry.

For more information about the map see Karen S. Cook, 'Thomas John Maslen and "The Great River or Desired Blessing" on his map of Australia', The Globe, no. 61, 2008, p.11.