202 J. B. CLELAND. 



As regards the cases mentioned by Rev. G. Taplin, the 

 sound would be carried a long way on the surface of the 

 lake. Some of the speakers in this discussion have men- 

 tioned the theory of the sounds being caused by the splitting 

 of exposed rocks, but I feel doubtful of this. Over most of 

 the region in New South Wales and Queensland to which 

 my own knowledge and that of my informants extends 

 regarding these sounds, there are no great masses of rock 

 visible. Besides, such an explosion would require to be 

 extremely loud to be heard 10 or 20 miles away. A force 

 to cause a report that would travel such a distance might 

 make a perceptible earth tremor, or leave traces which 

 would be observed at the place of occurrence. 



It may be mentioned that gypsum is very plentiful on 

 Yantara Station, near Lake Oobham, where tons of it could 

 easily be obtained. There is also a kind of slacked or 

 rotted gypsum, resembling slacked lime. Gypsum is like- 

 wise plentiful on Kallara Station, near Louth, on the Dar- 

 ling River. Sir Thos. Mitchell found aboriginal articles 

 4 made of lime ' at Fort Bourke, on the Darling. In 1838, 

 Joseph Hawdon noticed a great quantity of crystalized 

 lime or gypsum at Lake Bonney on the Murray River ; it 

 was in masses some tons weight. When I was surveying 

 at Silverton, near Broken Hill, in 1884-5, I saw several 

 outcrops of Limestone, and at one place a small lime-kiln 

 had been formed by the miners. I have merely mentioned 

 the above facts because limestone country is generally 

 iable to have subterranean cavities. Mud-springs — heaps 

 of damp earth or mud, forced up from below, with water 

 oozing out of the sides — are found in the north-western 

 portion of New South Wales. Some that I know of com- 

 mence about Yantabulla and extend to Eulo and Thargo- 

 mindah in Queensland. They follow a general course, 

 winding about much the same as a range of hills, with 



