EXPLOSIVE OR BOOMING NOISES IN CENTRAL AUSTRALIA. 197 



heard at 9 a.m, and one at 3 p.m. As regards the season 

 of the year, they were heard as follows: — Feb. (2), April 

 (1), July (3), August (1), Sept. (2), Oct. (1), Nov. (1). These 

 facts agree with Maso's opinion as to their frequency at 

 niglit, but do not seem to support the view as to their 

 greater prevalence in hot weather, though even in the 

 winter the weather in the interior of Australia may be 

 warm. As the Australian noises have been heard some- 

 times hundreds of miles inland, there can be no connection 

 with the sea ; further, no mountains, only low hills, exist 

 in the neighbourhood of their occurrence. These facts do 

 not fit in with Saderra Maso's suggestions. Earthquakes, as 

 in the Phillipines, can be excluded. What, then, remains as 

 a likely cause for them? It is almost certain they originate 

 in some way in the earth. I have been told they are not 

 uncommon in the Kimberley Districts of Western Australia 

 and that a native, being questioned by a white man con- 

 cerning them, said ' hill tumble down,' by which he meant 

 that huge masses of rock fell down or cracked apart amongst 

 the ranges. I suppose this explanation is a possible one 

 and perhaps the most likely, especially when it is borne in 

 mind that in the dry interior of Australia, the days are 

 often intensely hot and the nights exceedingly cold. This 

 might easily lead to considerable changes in size of the 

 rocks with perhaps the above results. 



It is quite possible, however, that here in Australia, as 

 well as in other parts of the world, as has been suggested, 

 two different phenomena are to be recognised. The sounds 

 heard on Lake Alexandrina by Taplin, on Lough Neagh, on 

 the Delta of the Ganges, and off the coast of Belgium, have, 

 as a common factor, extensive sheets of water. The sounds 

 in these places can hardly be explained by any rock-splittiug 

 hypothesis, and some other explanation is therefore neces- 

 sary. On the other hand, several of the occurrences in 



