EXPLOSIVE OR BOOMING NOISES IN CENTRAL AUSTRALIA. 201 



that at about the same moment, two or three people saw 

 a bright light flash across the sky towards the point where 

 the explosive sound originated. In considering the general 

 question of these booming noises, he thought the matter 

 was made more difficult and unsatisfactory, because to a 

 large extent the investigation had to be made without the 

 full facts of a particular case being known. 



Mr. R. H. Mathews said; It is quite gratifying to me that 

 Dr. Oleland has taken the trouble to bring this matter 

 before the Society for publication, because several years 

 ago I thought of writing an article upon it myself. The 

 best of any previous descriptions which I have seen is that 

 given by Hev. G. Taplin, to which I drew attention when 

 the present paper was introduced. On a few occasions I 

 have heard the noises myself, and have not infrequently 

 been told of similar experiences by squatters and others 

 living out in the quiet bush in the north-western districts 

 of New South Wales and Southern Queensland. My 

 theory has always been that the 'desert sound' was con- 

 nected with the cracking of the surface of the ground in 

 dry weather. Everyone who has been out in the interior 

 of this country knows of the huge ' sun-cracks ' in the 

 ground in many places. Some of these cracks would 

 extend down to larger fissures already in existence under 

 the ground. Such subterranean fissures would be more 

 or less damp and would lose some of their moisture on 

 the admission of dry air from above. This might cause 

 fracture of the material bounding the cavities and give rise 

 to the explosive sounds. This would account for the 

 rumbling or muffled character of the noises. I am of 

 opinion that the origin of the sounds has not been very 

 far from the places where they were heard. Oapt. Sturt 

 thought one of the explosions described by him was only 

 half a mile distant. 



