But there was a sudden fall to their hopes when a letter was received from him stating that the cliffs, the bay, and the head-lands were all built up on the airy foundation of a mirage.

The elves and sprites of this desolate region had been playing a hoax upon Goyder's party.

But it is no wonder that Goyder had been so open to deception after unexpectedly finding fresh water in the lake that had been so long known as salter than the sea.
On reaching the lake, Freeling found the water still almost fresh; but one of Goyder's men who accompanied him, told him that it had already receded half-a-mile since the latter's visit.

An attempt to float the punt was made, but after dragging it through mud and a few inches of water for a quarter of a mile, the men abandoned the attempt as hopeless.
Freeling and some of the party then started to wade through the slush, but after proceeding three miles, and then sounding only six inches of water, they returned.

Some of the more adventurous extended their muddy wade, but only met with a similar result.