26 AUSTRALIAN WEATHER. 



of ocean waves might do, while passing under a long, pliable, 

 floating body set at right angles to them. 



BURSTERS PROM SECONDARIES. 



The third and last modification results from a secondary. 

 Of this particular variety very few have been recorded on the 

 weather charts. They develop so suddenly that unless they are 

 actually in a state of evolution at the hour when observations are 

 taken (9 a.m.), the meteorologist has no indication of their 

 proximity. They develop on the south coast of New South Wales 

 through the formation of a " kink " in the outlying isobars of the 

 retreating high pressure. Prior to such a development the baro- 

 metric conditions are neutral or dormant in other words, the 

 existing high and low pressures have little grade, and are only 

 relatively high and low. Southerlies caused in this way partake 

 of the well known characteristics of secondaries, wherever they 

 may occur that is, violent and of small compass, most severe in 

 the extreme south east, and seldom affecting the coastal districts 

 north of Cape St. George. The depression which follows the 

 retreating high pressure brings on the following day, a southerly 

 of the ordinary character, the strength of which is regulated 

 according to the intensification or otherwise which has taken place 

 during the interval in the adjacent high and low pressures. 



BURSTERS NOT CONDUCIVE TO RAIN. 



The next point to be considered is the relation of bursters to 

 rainfall. The burster, on the whole, must be regarded as unfavour- 

 able to rain, for though its advent may benefit the coastal areas 

 to the extent of a few showers it serves as an indication that the 

 country west of the ranges is at least in a temporarily dry con- 

 dition. A succession of bursters especially denotes intermittent 

 rain in the interior. As a proof of this, and also as an evidence of 

 the comparative powerlessness of merely local weather conditions 

 to directly cause, or even to intensify, the burster, it is only neces- 

 sary to point out its frequent occurrence under circumstances 

 apparently most unfavourable for its development. 



