SURVEYORS DECEIVED BY MIRAGE. 393 



Australia, in April 1857, when an exploring party, 

 conducted by the Deputy Surveyor General of the 

 colony, was completely taken in by it. Ascending to 

 the summit of a hill " to the north he saw a belt of 

 gigantic gum trees beyond which appeared a sheet of 

 water, with elevated lands on the far side, wiiile to 

 the east was another large lake." These on further 

 examination, however, were found to consist, the gigantic 

 trees of stunted bushes, and the elevated lands, of 

 clods of earth. But the greatest surprise was when the 

 party reached Lake Torrens. The water was found 

 to be quite fresh, and appeared to stretch away "for 

 fifteen or twenty miles to the north west, with a 

 water horizon; there was an extensive bay to the 

 southward, while to the north a bluff headland, and 

 perpendicular cliffs were clearly discerned by a telescope. " 

 But having no boats with which to navigate the lake, the 

 surveyor returned to Adelaide to report his discovery 

 which created great rejoicing, as the northern frontier 

 had till then been supposed to be a waterless desert. 

 The Surveyor General immediately started, with boats, 

 to explore the newly-found waters. The public 

 disappointment at Adelaide may be imagined, when 

 a letter was received from this officer reporting that 

 "the cliffs, the headlands, and the grassy shores were 

 all built upon the basis of the mirage," and that the 

 lake had already receded half a mile, and was in no 

 place over six inches deep, being evidently a mere 

 flooded lagoon. * 



Before dismissing these phenomena of the desert 



* The History of Australian Exploration, 1788 to 1888, compiled 

 from State documents by Ernest Favense, published Sydney 1889, pp. 

 189 and 190. 



