92 AUSTRALIAN WEATHER. 



istics are so obtrusive that they cannot be overlooked, and they 

 are welcomed as the most pleasant relief after the high tempera- 

 tures and oppressive northerly winds which precede them. They 

 come in the late spring, all summer, and part of autumn, but as 

 a rule, in order to get a strong southerly an antecedent excessively 

 hot day or days must be experienced. The duration of a southerly 

 burster may be anything from two hours to ten days, but it is not 

 to be understood that the term burster is applied to the whole 

 period or duration of the southerly wind. What is called a 

 burster is the squall or sudden and violent change of wind direc- 

 tion, and the violent rush or " burst " which marks the advent of 

 this wind. We need not go into all the characteristics ; these will 

 be found in the Abercromby Prize Essay on this subject. 1 It is 

 there explained that the south wind comes in front of an approach- 

 ing anticyclone, and that it is felt from West to Eastern Australia, 

 but it is only on the eastern coast, where, aided by the smaller 

 friction of the ocean and the shelter which the mountains afford 

 from other winds, that the southerly becomes more vigorous and 

 rushes northwards in a squall, which happens so suddenly and 

 with such force, that at times ships drag their anchors in Sydney 

 harbour. 



It is not definitely made out yet that these storms are ever 

 " line storms " in the sense that the change of wind comes as the 

 dip in the isobars passes over each place in succession, but there 

 are many facts which suggest that such is the fact in some instances. 

 Our present purpose is to describe a "burster" as a type of 

 Australian weather. The essential feature of it is a sharp 

 A ; in Chart 31 such a depression is shewn existing over Victoria 

 and Tasmania, with its axis lying from north-north-west to south- 

 south-east. An anticyclone of good energy for this time of the 

 year exists to the west, and hot northerly winds occupy northern 

 Australia ; these are the elements for the good burster that 

 followed. As a general rule, 2 the position and character of two 



1 Journal Royal Society, N. S. Wales, Vol. xxvm. 

 2 See Moving Anticyclones, p. 4. 



